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Introduction and Objective: Ticks (Acari:Ixodida) are dangerous ectoparasites and, at the same time, vectors and/or resevoirs of many pathogens, among others Borrelia burgdorferi sensu lato, Anaplasma phagocytophilum and Babesia microti. These ethiological agents of Lyme borreliosis, anaplasmosis and babesiosis are transferred to humans mainly by ticks during feeding. The aim of this study was to estimate the potential risk of human exposure to tick borne infection of B. burgdorferi s.l., A. phagocytophilum and B. microti in selected areas of Poprad Landscape Park in southern Poland [PLP]., Material and Methods: Ixodes ricinus ticks were collected from vegetation by the flagging method. Under a stereoscopic microscope, specimens were determined to the species and developmental stage. In total, DNA was isolated from 363 ticks. To detect B. burgdorferi s.l,.two pairs of primers specific to the flagelline gene were used. In turn, to detect A. phagocytophilum and B. microti, two pairs of primers specific to the 16S rRNA gene fragment and 18S rRNA gene fragment were used, respectively. The amplification products were separated electrophoretically in 2% ethidium bromide stained agarose gels, and visualized under ultra violet light., Results: Generally, pathogens were observed in 19.6% of ticks. Borrelia burgdorferi sensu lato was detected in 11.8% of studied ticks. In turn, A. phagocytophlium and B. microti were presented, respectively, in 0.3% and 7.4% of examined I. ricinus., Conclusions: The study indicated a potentially high risk of human exposure to infection with tick-borne pathogens, mainly B. burgdorferi s.l. and B. microti, in the areas of PLP. In turn, the presence of A. phagocytophilum in lower percentage was shown in the studied ticks.

Background: Understanding how parasitoids respond to temperature is crucial for improving biological control strategies under the context of global warming. This study examined the suitability of Myzus persicae and its parasitoid Aphidius gifuensis to varying temperature conditions, as well as the stage-specific response of A. gifuensis to high temperatures., Results: High temperatures had a significant impact on the both M. persicae and A. gifuensis. When exposed to 36°C, M. persicae developed more slowly and produced smaller adults compared to control, regardless of the duration of exposure (2, 4 or 6 h); additionally, the survival rate of M. persicae nymphs sharply decreased under these conditions. Exposure to 36°C for 4 h negatively impacted the development of A. gifuensis. Female parasitoids exposed to 32°C developed into smaller adults, whereas males exposed to all three temperature levels were smaller compared to control group. Female parasitoids exposed to high temperatures, regardless of the specific heat level and duration, exhibited reduced longevity and decreased fecundity. None of the parasitoids exposed to 36°C for 6 h daily developed into adults. Heat treated during early developmental stages (2 and 4 days old) had a greater influence on parasitoid development, whereas heat treatment at 4 and 6 days old had a more significant impact on its fecundity., Conclusion: High temperatures not only directly affected the performance of A. gifuensis, but also exerted indirect effects by influencing the quality of the host aphids M. persicae. The deleterious effects of high temperature on larvae can persist into the adult stage, affecting the longevity and reproduction of adults. These findings are important for the utilization of A. gifuensis in the control of M. persicae in warming environments. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

In Egypt, tick-borne diseases pose a significant threat to human and animal health, and the threat to dromedaries (Camelus dromedarius), the country's dominant camelid species, is of particular concern. These animals are frequently infested with ticks, and may thus develop tick-borne diseases or become reservoirs of tick-borne pathogens. However, there is a paucity of data on tick infestation in Egyptian camels, especially in the south of the country. Accordingly, we aimed to determine the prevalence of tick infestation in southern Egyptian camel populations (in Luxor and Aswan governorates), and identify the hemoprotozoan parasites carried by camel-infesting ticks. Camels were checked for ticks during veterinary examination at quarantine and household checks, and ticks were collected from infested camels for species identification using morphological examination and PCR analyses. Tick and hemoprotozoan species were identified using Basic Local Alignment Search Tool analysis with subsequent confirmation in phylogenetic analyses. All camel-infesting ticks belonged to the species Hyalomma dromedarii, and were clustered with ticks of this species previously found in Egypt in a phylogenetic tree based on the 16S rRNA gene. Molecular analysis targeting the 18S rRNA gene revealed the presence of hitherto undetected hemoprotozoan parasites, Colpodella spp., in 30/297 (10.1 %) camel-infesting ticks. In phylogenetic analysis, these Colpodella spp. were highly homologous (94-98.6 %) with Colpodella spp. previously deposited in GenBank with accession numbers OQ540590Q, MH208621, and GQ411073, which relate to Colpodella spp. previously detected from Haemaphysalis longicornis, Rhipicephalus haemaphysaloides, and humans in China. PCR analyses with spherical body protein-4 (SBP-4) gene-specific primers revealed Babesia bovis in 16/297 (5 %) of camel-infesting ticks, however, Babesia bigemina and Theileria annulata were not detected. Here, we report the first detection of Colpodella spp. in H. dromedarii in Egypt. Further epidemiological studies are needed to assess the risk to camels and humans, and the transmission dynamics. Based on the high tick infestation rates in Egyptian camels and the identification of previously unreported protozoan hemoparasites in ticks, we consider that the dromedary should be subject to surveillance as a sentinel species for tick-borne diseases in Egypt. Our findings underline the need for surveillance and collecting data on lesser known pathogens circulating in camel-infesting ticks, as part of a public health strategy for dealing with tick-borne diseases in Egypt., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

Background: To improve integrated pest management (IPM) performance it is essential to assess pesticide side effects on host plants, insect pests, and natural enemies. The green peach aphid (Myzus persicae Sulzer) is a major insect pest that attacks various crops. Aphidius gifuensis is an essential natural enemy of M. persicae that has been applied effectively in controlling M. persicae. Thiamethoxam is a neonicotinoid pesticide widely used against insect pests., Results: The current study showed the effect of thiamethoxam against Solanum tuberosum, M. persicae, and A. gefiuensis and the physiological and molecular response of the plants, aphids, and parasitoids after thiamethoxam application. Thiamethoxam affected the physical parameters of S. tuberosum and generated a variety of sublethal effects on M. persicae and A. gefiuensis, including nymph development time, adult longevity, and fertility. Our results showed that different thiamethoxam concentrations [0.1, 0.5, and 0.9 μm active ingredient (a.i.)/L] on different time durations (2, 6, and 10 days) increased the antioxidant enzyme activities SOD, POD, and CAT of S. tuberosum, M. persicae, and A. gefiuensis significantly compared with the control. Our results also showed that different thiamethoxam concentrations (0.1, 0.5, and 0.9 μm a.i./L) on different time durations (2, 6, and 10 days) increased the expression of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), acetylcholinesterase (AChE), carboxylesterase (CarE) and glutathione-S-transferase (GST) genes of S. tuberosum, M. persicae, and A. gefiuensis compared with the control., Conclusion: Our findings reveal that using thiamethoxam at suitable concentrations and time durations for host plants and natural enemies may enhance natural control through the conservation of natural enemies by overcoming any fitness disadvantages. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Females of host-feeding parasitic wasps often partition hosts of different stages for feeding and parasitization, but the underlying behavioral mechanisms are largely unknown, making it difficult to evaluate parasitoid-host interactions and their effects on biological control success. Tamarixia triozae (Burks) is an ectoparasitoid of tomato-potato psyllid Bactericera cockerelli (Šulc), which utilizes nymphs and kills them both by parasitization and host feeding. In this study, we exposed female wasps to 1st- to 5th-instar psyllid nymphs simultaneously and made 13-h continuous video recording of parasitoid-host interactions. We then quantified host stage-dependent handling time for feeding and oviposition and behaviors of parasitoid attacks and host defenses from encountering to successful feeding and oviposition. Female wasps were more likely to encounter and evaluate older hosts. However, the encounter and evaluation did not necessarily result in the success of feeding and oviposition. Our findings suggest that (i) T. triozae continues to assess the host using its ovipositor after the evaluation phase, (ii) females prefer the mid-aged hosts for feeding piercing and feeding and the later instars for oviposition probing and oviposition, (iii) the combination of stage-specific host nutrition value, integument thickness and defense behavior determines the success of feeding attacks, and (iv) the optimal host resource for parasitoid offspring fitness defines host stage selection for oviposition. This study contributes to our understanding of parasitoid-host interactions and mechanisms behind host stage selections., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)

Piroplasms, which include the agents of cattle fever and human and dog babesiosis, are a diverse group of blood parasites of significant veterinary and medical importance. The invasive Asian longhorned tick, Haemaphysalis longicornis , is a known vector of piroplasms in its native range in East Asia and invasive range in Australasia. In the USA, H. longicornis has been associated with Theileria orientalis Ikeda outbreaks that caused cattle mortality. To survey invasive populations of H. longicornis for a broad range of piroplasms, 667 questing H. longicornis collected in 2021 from 3 sites in New Jersey, USA, were tested with generalist piroplasm primers targeting the 18S small subunit rRNA (395–515 bp, depending on species) and the cytochrome b oxidase loci (1009 bp). Sequences matching Theileria cervi type F (1 adult, 5 nymphs), an unidentified Theileria species (in 1 nymph), an undescribed Babesia sensu stricto (‘true’ Babesia , 2 adults, 2 nymphs), a Babesia sp. Coco (also a ‘true Babesia ’, 1 adult, 1 nymph), as well as Babesia microti S837 (1 adult, 4 nymphs) were recovered. Babesia microti S837 is closely related to the human pathogen B. microti US-type. Additionally, a 132 bp sequence matching the cytochrome b locus of deer, Odocoileus virginanus , was obtained from 2 partially engorged H. longicornis. The diverse assemblage of piroplasms now associated with H. longicornis in the USA spans 3 clades in the piroplasm phylogeny and raises concerns of transmission amplification of veterinary pathogens as well as spillover of pathogens from wildlife to humans.

Ticks (Ixodida) are ecologically important ectoparasites that may impact human health and economic activities. Parasitoid wasps are natural enemies of ticks and a potential option for its biological control. In the present study, we recorded parasitism of the nymphs of the tick Amblyomma nodosum by the parasitoid wasp Ixodiphagus hookeri. The ticks, in turn, were parasitizing white-bearded manakins, Manacus manacus (Passeriformes: Pipridae) in the União Biological Reserve, one of the last major remnants of lowland rainforest in Rio de Janeiro state, southeastern Brazil. During the collection of ectoparasites from two manakins in this reserve, 20-30 parasitoid wasps hatched spontaneously from two of the ticks collected. The species of the tick nymphs and adult wasps were identified using morphological traits and molecular analyses. This record is the first documented case of I. hookeri parasitizing A. nodosum and the first time that parasitoid wasps have been found in ticks parasitizing birds in Brazil. This is also the first record of Ixodiphagus from southeastern Brazil in more than a century, with the only other record dating back to 1914. The record presented here provides valuable new information on the biology of this tick and its parasitoids, and new insights into this interspecific interaction. Further research on these vertebrate-tick-wasp interactions will be necessary to better understand the respective roles of the organisms involved in these processes., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In recent years, concerns about Chagas disease in the United States have increased. Triatomine bug (Hemiptera: Reduviidae) populations are the vectors of the parasite Trypanosoma cruzi Chagas (Trypanosomatida: Trypanosomatidae), which causes Chagas disease, although the route of transmission is considered inefficient in United States. However, more studies on triatomine feeding and defecation behavior are needed. In this study, six related biological parameters from two populations of Triatoma protracta protracta (Uhler) and T. p. woodi (Uhler) from Mexican locations near the U.S. border were evaluated. The four population life cycles were less than 6 mo (161-171 d), with 9-10 blood meals needed to molt. Mortality rates were similar (31-38%) among the four populations. Triatoma p. woodi from Hidalgo, Coahuila was the most aggressive one. Feeding times were over 10 min, increasing with instar in all populations. Defecation behaviors varied among populations. High percentages of male and female fourth- and fifth-instar nymphs of T. p. protracta from Imuris and both populations of T. p. woodi defecated immediately after or <1 min of feeding. Lower percentages were observed for T. p. protracta from Jacumé. Because most parameters were similar among the four populations, independent of their subspecies and their geographic origin, we considered that T. p. protracta and T. p. woodi are efficient vectors of T. cruzi. In contrast, defecation patterns were noticeably different among some of the four triatomine populations studied. Our results highlight the importance of studying the biological parameters of local triatomine populations. They also contribute to increasing the knowledge of North American triatomine behavior and defecation patterns., (© The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America.All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Vector competence of triatomines (kissing bugs) for Trypanosoma cruzi transmission depends on the parasite-vector interaction and the genetic constitution of both. This study evaluates the susceptibility and vector competence of Rhodnius robustus experimentally infected with T. cruzi IV (TcIV). Nymphs were fed on infected mice or an artificial feeder with blood containing culture-derived metacyclic trypomastigotes (CMT) or blood trypomastigotes (BT). The intestinal contents (IC) and excreta of the insects were examined by fresh examination and kDNA-PCR. The rate of metacyclogenesis was also determined by differential counts. Fifth instar nymphs fed with CMT ingested a greater blood volume (mean of 74.5 μL) and a greater amount of parasites (mean of 149,000 CMT/μL), and had higher positivity in the fresh examination of the IC. Third instar nymphs fed with CMT had higher positivity (33.3%) in the fresh examination of the excreta. On the 20th day after infection (dai), infective metacyclic trypomastigote (MT) forms were predominant in the excreta of 3/4 experimental groups, and on the 30th dai, the different parasitic forms were observed in the IC of all the groups. Higher percentages of MT were observed in the excreta of the 5th instar nymphs group (84.1%) and in the IC of the 3rd instar nymphs group (80.0%). Rhodnius robustus presented high susceptibility to infection since all nymphs were infected, regardless of the method used for blood meal, in addition these insects demonstrated vector competence for TcIV with high rates of metacyclogenesis being evident., (Copyright © 2021. Published by Elsevier Inc.)

Huanglongbing (HLB) is a destructive disease of citrus primarily transmitted by the Asian citrus psyllid (ACP). Biocontrol of ACP is an environmentally sustainable alternative to chemicals. However, the risk of parasitoid rational application in ACP biocontrol has never been evaluated. Here we show, the dominant parasitoid of ACP, Tamarixia radiata, can acquire the HLB pathogen Candidatus Liberibacter asiaticus (CLas) and transmit it horizontally when probing ACP nymphs. If these ACP nymphs survive the probing, develop to adults and move to healthy plants, CLas can be transmitted to citrus leaves during feeding. We illustrate the formerly unrecognized risk that a parasitoid can potentially serve as a phoretic vector of the pathogen transmitted by its host, thus potentially diminishing some of the benefits it confers via biocontrol. Our findings present a significant caution to the strategy of using parasitoids in orchards with different infection status of insect-vectored pathogens., (© 2021. The Author(s).)

In 2017, a single adult Triatoma sanguisuga (LeConte) (Hemiptera: Reduviidae) was identified from Indian Cave State Park in Nemaha County, NE. The following summer, a single adult specimen was found in a 4-H insect collection at the Nebraska State Fair from Richardson County. A subsequent investigation found that these were collected from a residence in Richardson County and three more adults were collected in 2019. In 2020, the latter three kissing bugs were submitted to Public Health Command-Central's DoD Food Analysis and Diagnostic Laboratory (DOD FADL) for confirmatory species identification and diagnostic testing for Trypanosoma cruzi, the causative agent of Chagas disease. One specimen tested positive for T. cruzi using a real-time dual-target PCR screen followed by confirmatory dual-target traditional PCR. Based on these findings, a survey plan was developed for Richardson and surrounding counties in southeast Nebraska. In July of 2020, two adult and seven nymphs (multiple instars) of T. sanguisuga were collected in Richardson County, one of which tested positive for T. cruzi. This is the first record of an established population of T. sanguisuga and T. cruzi-infected kissing bugs in Nebraska., (Published by Oxford University Press on behalf of Entomological Society of America 2021.)

Chagas disease is caused by Trypanosoma cruzi and transmitted by the triatomine Mepraia spinolai in the southwest of South America. Here, we examined the T. cruzi-infection dynamics of field-caught M. spinolai after laboratory feeding, with a follow-up procedure on bug populations collected in winter and spring of 2017 and 2018. Bugs were analyzed twice to evaluate T. cruzi-infection by PCR assays of urine/fecal samples, the first evaluation right after collection and the second 40 days after the first feeding. We detected bugs with: the first sample positive and second negative (+/-), the first sample negative and second positive (-/+), and with both samples positive or negative (+/+; -/-). Bugs that resulted positive on both occasions were the most frequent, with the exception of those collected in winter 2018. Infection rate in spring was higher than winter only in 2018. Early and late stage nymphs presented similar T. cruzi-infection rates except for winter 2017; therefore, all nymphs may contribute to T. cruzi-transmission to humans. Assessment of infection using two samples represents a realistic way to determine the infection a triatomine can harbor. The underlying mechanism may be that some bugs do not excrete parasites unless they are fed and maintained for some time under environmentally controlled conditions before releasing T. cruzi, which persists in the vector hindgut. We suggest that T. cruzi-infection dynamics regarding the three types of positive-PCR results detected by follow-up represent: residual T. cruzi in the rectal lumen (+/-), colonization of parasites attached to the rectal wall (-/+), and presence of both kinds of flagellates in the hindgut of triatomines (+/+). We suggest residual T. cruzi-infections are released after feeding, and result 60-90 days after infection persisting in the rectal lumen after a fasting event, a phenomenon that might vary between contrasting seasons and years., Competing Interests: The authors have declared that no competing interests exist.

Understanding the abiotic and biotic variables affecting tick populations is essential for studying the biology and health risks associated with vector species. We conducted a study on the phenology of exotic Haemaphysalis longicornis (Asian longhorned tick) at a site in Albemarle County, Virginia, United States. We also assessed the importance of wildlife hosts, habitats, and microclimate variables such as temperature, relative humidity, and wind speed on this exotic tick's presence and abundance. In addition, we determined the prevalence of infection with selected tick-borne pathogens in host-seeking H. longicornis. We determined that the seasonal activity of H. longicornis in Virginia was slightly different from previous studies in the northeastern United States. We observed nymphal ticks persist year-round but were most active in the spring, followed by a peak in adult activity in the summer and larval activity in the fall. We also observed a lower probability of collecting host-seeking H. longicornis in field habitats and the summer months. In addition, we detected H. longicornis on several wildlife hosts, including coyote (Canis latrans), eastern cottontail (Sylvilagus floridanus), raccoon (Procyon lotor), Virginia opossum (Didelphis virginiana), white-tailed deer (Odocoileus virginianus), woodchuck (Marmota monax), and a Peromyscus sp. mouse. This latter record is the first detection of a larval H. longicornis on a North American rodent host important to the enzootic maintenance of tick-borne pathogens of humans and animals. Finally, we continued to detect the exotic piroplasm parasite, Theileria orientalis Ikeda, in H. longicornis as well as other pathogens, including Rickettsia felis, Anaplasma phagocytophilum (AP-1), and a Hepatozoon sp. previously characterized in Amblyomma americanum. These represent some of the first detections of arthropod-borne pathogens native to the United States in host-seeking H. longicornis. These data increase our understanding of H. longicornis biology in the United States and provide valuable information into the future health risks associated with this tick and pathogens., (Copyright © 2021. Published by Elsevier GmbH.)

This study aimed to investigate whether the infection intensity of Theileria orientalis Ikeda type organisms within Haemaphysalis longicornis larvae and nymph stages fluctuated over 6 mo after feeding as larvae on infected calves in the field. Naïve larvae, hatched from eggs, were fed on infected calves for 5 days while contained within cotton socks glued over the calves' ears. Larvae were first sampled immediately post-feeding and then sampled every 3 wk for 23 wk in total, after molting to nymphs. All larvae and nymphs were tested for T. orientalis Ikeda organisms using quantitative PCR. The qPCR results showed that the infection intensity of Haemaphysalis longicornis larvae and nymphs was not constant over the sampling period, and after initially dropping after molting to nymphs, it then rose with fasting to a maximum at 17 and 23 wk post-feeding. The significant rise in T. orientalis Ikeda organisms observed at 23 wk postfeeding may explain why more severe clinical cases of bovine theileriosis in New Zealand are seen in the spring when nymphs are the predominant instar questing., (© American Society of Parasitologists 2021.)

Background: Relatively little is known about how pathogens transmitted by vector insects are affected by changing temperatures analogous to those occurring in the present global warming scenario. One expectation is that, like their ectothermic vectors, an increase in temperature could reduce their fitness. Here, we have investigated the effect of high temperatures on the abundance of Trypanosoma cruzi parasites during infection in the vector Triatoma pallidipennis., Methods: We exposed T. pallidipennis nymphs to two strains (Morelos and Chilpancingo) of T. cruzi. Once infected, the fifth-instar bugs were distributed among three different temperature groups, i.e. 20, 30, and 34 °C, and the resulting parasites were counted when the bugs reached adulthood., Results: The number of parasites increased linearly with time at 20 °C and, to a lesser extent, at 30 °C, especially in the Chilpancingo compared to the Morelos strain. Conversely, at 34 °C, the number of parasites of both strains decreased significantly compared to the other two temperatures., Conclusions: These results suggest negative effects on the abundance of T. cruzi in T. pallidipennis at high temperatures. This is the first evidence of the effect of high temperatures on a pathogenic agent transmitted by an insect vector in the context of global warming. Further tests should be done to determine whether this pattern occurs with other triatomine species and T. cruzi strains., (© 2021. The Author(s).)

Borrelia burgdorferi, the spirochete that causes Lyme disease, is endemic and widespread in Wisconsin. Research in the northeastern United States has revealed a positive association between Babesia microti, the main pathogen that causes babesiosis in humans, and Bo. burgdorferi in humans and in ticks. This study was conducted to examine associations between the disease agents in the Upper midwestern United States. Ixodes scapularis Say nymphs (N = 2,858) collected between 2015 and 2017 from nine locations in Wisconsin were tested for Babesia spp. and Borrelia spp. using real-time PCR. Two species of Babesia were detected; Ba. microti and Babesia odocoilei (a parasite of members of the family Cervidae). Prevalence of infection at the nine locations ranged from 0 to 13% for Ba. microti, 11 to 31% for Bo. burgdorferi sensu stricto, and 5.7 to 26% for Ba. odocoilei. Coinfection of nymphs with Bo. burgdorferi and Ba. odocoilei was detected in eight of the nine locations and significant positive associations were observed in two of the eight locations. The prevalence of nymphal coinfection with both and Bo. burgdorferi and Ba. microti ranged from 0.81 to 6.5%. These two pathogens were significantly positively associated in one of the five locations where both pathogens were detected. In the other four locations, the observed prevalence of coinfection was higher than expected in all but one site-year. Clinics and healthcare providers should be aware of the association between Ba. microti and Bo. burgdorferi pathogens when treating patients who report tick bites., (© The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America.All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Ticks (Ixodidae, also known as hard ticks) as principal vectors of zoonotic diseases such as severe fever with thrombocytopenia syndrome (SFTS), Lyme borreliosis, relapsing fever, anaplasmosis, ehrlichiosis, babesiosis, coxiellosis (Q fever), and tularemia pose a major public health threat. This study was conducted to identify the distribution profile of ticks and tick-borne pathogens in Daejeon and the adjacent areas in South Korea, where no such epidemiological study has been conducted. From April to October 2019, 16,765 ticks were collected from three genera and four species: Haemaphysalis longicornis (n = 14,949; 89.2 %), Haemaphysalis flava (n = 987; 5.9 %), Ixodes nipponensis (n = 828; 5.0 %), and Amblyomma testudinarium (n = 1; 0.01 %). Homogenized samples of ticks were screened by real-time reverse transcription polymerase chain reaction (PCR), real-time PCR, and PCR for the presence of the following tick-borne pathogens: SFTS virus (SFTSV), Borrelia spp., Babesia microti, Coxiella burnetii, Francisella tularensis, Anaplasma phagocytophilum, and Ehrlichia spp. As a result, SFTSV (2 cases), Borrelia spp. (32 cases), and Babesia microti (7 cases) were detected. The findings of this study will contribute to the prevention and management of tick-borne zoonoses., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Triatomine bugs aggregate with conspecifics inside shelters during daylight hours. At dusk, they leave their refuges searching for hosts on which to blood feed. After finding a host, triatomines face the threat of being killed, because hosts often prey on them. As it is known that many parasites induce the predation of intermediate hosts to promote transmission, and that ingestion of Trypanosoma cruzi-infected bugs represents a very effective means for mammal infection, we hypothesized that trypanosomes induce infected bugs to take increased risk, and, as a consequence, be predated when approaching a host. Therefore, we evaluated whether the predation risk and predation rates endured by Rhodnius prolixus increase when infected with T. cruzi. Assays were performed in square glass arenas offering one central refuge to infected and uninfected 5th instar nymphs. A caged mouse was introduced in each arena after a three-day acclimation interval to activate sheltered insects and induce them to approach it. As hypothesized, a significantly higher proportion of infected insects was predated when compared with uninfected ones (36% and 19%, respectively). Indeed, T. cruzi-infected bugs took higher risk (Approximation Index = 0.642) when compared with healthy ones (Approximation Index = 0.302) and remained outside the shelters when the host was removed from the arena. Our results show that infection by T. cruzi induces bugs to assume higher risk and endure higher predation rates. We reveal a hitherto unknown trypanosome-vector interaction process that increases infected bug predation, promoting increased rates of robust oral transmission. The significant consequences of the mechanism revealed here make it a fundamental component for the resilient maintenance of sylvatic, peridomestic and domestic cycles., Competing Interests: The authors have declared that no competing interests exist.

Three behaviors of epidemiological importance, namely feeding latency, feeding duration and defecation latency, for six populations of Meccus phyllosomus longipennis (Usinger) from areas of central, western and north-central Mexico with high (HP) and low (LP) prevalence of Trypanosoma cruzi (Chagas) human infection were evaluated in this study. The median feeding latency (the time taken to begin feeding) was highly variable between instars. Within-instar comparisons showed that at least 65% of the LP populations (N3 to adult) started to feed significantly (P < 0.05) later than the HP population, with N1 showing no difference, and N2 from LP populations feeding sooner than those from HP populations. The six populations had similar median feeding durations within instars. A higher (P < 0.05) percentage of the instars from HP populations defecated faster than the respective instars from the three LP populations. Approximately 25% of the young nymphs (N1 to N3) and females in the HP populations defecated < 2 min postfeeding, compared with 4%-6% of the young nymphs and 1.3%-3% of females in the LP populations. Moreover, 17.7%-38.8% of the older nymphs (N4 to N5) in the HP populations and 6.8%-13.4% in the LP populations defecated during or immediately after feeding. Our results indicate that the HP populations have a greater potential than the LP populations to transmit T. cruzi infections, which may underlie the differences in the prevalence of T. cruzi infection in some areas where M. p. longipennis is currently distributed., (© 2020 Institute of Zoology, Chinese Academy of Sciences.)

Ixodiphagus endoparasitoid wasps are natural tick enemies that can reduce their abundance. In this study, we investigated the presence of Ixodiphagus hookeri in Haemaphysalis concinna and Ixodes ricinus ticks in the Slovak Karst (southern Slovakia) and analysed the ecological and physiological relationships in the parasitoid-host system. Unfed H. concinna and I. ricinus nymphs harvested from vegetation were fed on rabbits. The engorged specimens were kept at 25 °C and 75% RH until the emergence of the adult wasps. For the first time in Europe, we found the presence of I. hookeri in two species of ticks collected in the same locality and compared their development in these tick species. The prevalence of wasps in H. concinna and I. ricinus during their spring activity was estimated at 10.64% and 27.78%, respectively. The presence of the wasps did not affect the duration of nymph feeding. Engorged wasp-infected ticks achieved higher body mass than non-infected specimens. In both tick species, there were no differences in the length of the development period and the number and sex ratio of adult I. hookeri. The analysed indicators and characteristics of the I. hookeri wasp-tick system can be used in research on tick control.

Background: Babesia microti, a malaria-like pathogen, is increasing in mammal and human populations in endemic areas and is unlikely to be the sole result of horizontal pathogen transmission., Methods: Peromyscus leucopus mice, natural reservoir hosts, were infected via Ixodes scapularis nymphs. Infected parental females (n = 6) produced F1 offspring (n = 36) that were screened for B. microti using quantitative PCR. Xenodiagnostic larvae were fed on infected offspring to determine horizontal transmission and pathogen viability. Fifty engorged larvae were screened; the rest were allowed to molt and then screened to determine transstadial transmission. Infected F1 generation offspring were placed in breeding groups, producing 34 F2 offspring and screened for B. microti infection. Chronic infection was monitored in parental females since time of initial vector infection., Results: Vertical transmission of B. microti was 74% efficient in offspring born in the first 6 months. Horizontal transmission occurred in larvae (61% prevalence) and molted nymphs (58% prevalence); these nymphs were able to infect susceptible hosts. F2 generation offspring infection prevalence was 38%. Chronic infection persisted for 1 year in some adults., Conclusions: These results demonstrate that vertical transmission is an important nonvector-mediated pathway of B. microti transmission in the natural reservoir host., (© The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Rice (Oryza sativa L.) is the main cereal crop in many Asian countries. The Asian rice planthoppers, Nilaparvata lugens (Stål) (brown planthopper), Sogatella furcifera (Horváth) (white-backed planthopper), and Laodelphax striatellus (Fallén) (small brown planthopper) (Hemiptera: Delphacidae), are the most economically important pests of rice. These three rice planthopper species often co-occur in the same paddy field. Traditionally, species identification of individuals of the three rice planthopper species has relied on morphological characters, but accurate discrimination of early-instar nymphs is very difficult, even for expert researchers. In this study, we developed a rapid one-step multiplex PCR assay using conserved and species-specific 5.8S-ITS2 rDNA gene primers for simultaneous identification of individuals of the three rice planthopper species. The multiplex PCR results showed that the three rice planthopper species could be identified accurately based on the length of the resultant amplicon, regardless of the individual developmental stage. Furthermore, we applied this assay for the first accurate quantification of early-instar nymphs of each rice planthopper species in paddy fields. Notably, we found that the species composition of early-instar nymphs cannot be extrapolated from that of adults. Thus, the multiplex PCR assay developed here facilitates detection of each rice planthopper species at the beginning of outbreaks in paddy fields., Competing Interests: Toshihisa Yashiro is an inventor on a Japanese patent application related to this work filed by National Agriculture and Food Research Organization (No. 2020-146157, filed 31 August 2020) on the “Method, primer set, and kit for species identification of rice planthoppers”. This does not alter our adherence to PLOS ONE policies on sharing data and materials. Sachiyo Sanada-Morimura has no conflict of interest

Even though Paranosema locustae is widely used in China as a biological agent for controlling grasshoppers, the mortality rate is initially quite low. This study sought to determine whether the simultaneous use of P. locustae and Beauveria bassiana would be a more effective control strategy. Additionally, changes in the intestinal microbial communities of migratory locusts infected with the two pathogens were analyzed to investigate the roles of gut microbes in pathogen-host interactions. The mortality rate of locusts inoculated with B. bassiana and P. locustae simultaneously was not significantly higher than expected, but the mortality rates of locusts inoculated with B. bassiana 3, 6, and 9 days after inoculation with P. locustae were significantly higher than if their effects were additive, indicating synergism. A MiSeq analysis found that Weissella was the most common bacterium, representing 41.48% and 51.62% of the total bacteria in the mid- and hindguts, respectively, and the bacterial declines were greatest during dual infections with B. bassiana and P. locustae. The appropriately timed combined application of P. locustae and B. bassiana was more effective against locusts than either treatment alone. Moreover, the combined inoculation of the two pathogens changed the gut microflora of locusts, indicating the potential relevancy of their synergistic effects on locust control., (© 2020 Institute of Zoology, Chinese Academy of Sciences.)

Background: Migratory birds can cross geographical and environmental barriers and are thereby able to facilitate transmission of tick-borne pathogens both as carriers of infected ticks and as reservoirs of pathogenic microorganisms. Ixodes ricinus is one of the most abundant tick species in the Northern Hemisphere and a main vector of several Babesia species, some which pose a potential threat to human and animal health. At present only two cases of overt babesiosis in humans have so far been reported in Sweden. To better understand the potential role of birds as disseminators of zoonotic Babesia protozoan parasites, we investigated the presence of Babesia species in ticks removed from migratory birds., Methods: Ticks were collected from birds captured at Ottenby Bird Observatory, south-eastern Sweden, from March to November 2009. Ticks were molecularly identified to species, and morphologically to developmental stage, and the presence of Babesia protozoan parasites was determined by real-time PCR., Results: In total, 4601 migratory birds of 65 species were examined for tick infestation. Ticks removed from these birds have previously been investigated for the presence of Borrelia bacteria and the tick-borne encephalitis virus. In the present study, a total of 1102 ticks were available for molecular analysis of Babesia protozoan parasites. We found that 2.4% of the ticks examined, all I. ricinus, were positive for mammal-associated Babesia species. Out of all Babesia-positive samples, Babesia venatorum was the most prevalent (58%) species, followed by Babesia microti (38%) and Babesia capreoli (4.0%). B. venatorum and B. capreoli were detected in I. ricinus larvae, whereas B. microti was only present in I. ricinus nymphs. This supports the view that the two first-mentioned species are vertically (transovarially) transmitted in the tick population, in contrast to B. microti. The largest number of Babesia-infected ticks was removed from the common redstart (Phoenicurus phoenicurus) and European robin (Erithacus rubecula)., Conclusions: This study reveals that Babesia protozoan parasites are present in ticks infesting migratory birds in south-eastern Sweden, which could potentially lead to the dissemination of these tick-borne microorganisms into new areas, thus posing a threat to humans and other mammals.

The escape kinetics from the anterior midgut (AM) of Trypanosoma cruzi during the initial steps of infection was assessed in Triatoma infestans, as well as its ability to survive migration in the digestive tract of the vector. All the four strains evaluated survived and reached variable parasite densities. After 49-50 days, YuYu [discrete typing units (DTU) I] strain reached the highest parasite numbers in the rectum followed by Bug (DTU V), CL-Brener (DTU VI) and Dm28c (DTU I). All strains accomplished metacyclogenesis. Bug strain reached the highest numbers of metacyclic trypomastigotes followed by YuYu and CL-Brener/Dm28c. A remarkable parasite reduction in the AM for Bug strain, but not Dm28c was noticed at 72 h of infection. In the posterior midgut + rectum high densities of parasites from both strains were detected at this period indicating the parasites crossed the AM. For Dm28c strain, in infections initiated with trypomastigotes, parasites left AM faster than those starting with epimastigotes. In conclusion, T. cruzi strains from different DTUs were able to infect T. infestans reaching variable parasite densities. The kinetics of migration in the digestive tract may be affected by strain and/or the evolutive form used for infection.

The potential of the parasitoid Psyllaephagus bliteus Riek for the biological control of the eucalyptus pest Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae) nymphs is high. This research sought to analyze the courtship, male competition, and mating behavior of P. bliteus at the proportions of 1:1 and 2:1 males to female in a Petri dish (5 cm diameter), and to describe the ovary histology of virgin and mated females of this parasitoid. At 1:1, males touch the antennae and thorax-abdomen of females during courtship, but females avoid mate attempts before they are 48 h old. At 2:1, the competition between male parasitoids inhibits mating. The histology of ovaries of virgin and mated P. bliteus females is similar, with two well-defined germarium and vitellarium regions, with oocytes at different developmental stages, including mature ones rich in yolk and with eggshell. A clearer understanding of the reproductive behavior and histology of P. bliteus aids in the use of this parasitoid for the biological control of G. brimblecombei., (© The Author(s) 2021. Published by Oxford University Press on behalf of Entomological Society of America.)

Anaplasma phagocytophilum and some piroplasm species are pathogens mainly transmitted by Ixodes ricinus. Considering that this tick species is predominant in north-western Spain, individual specimens (652 nymphs, 202 females and 202 males) and 23 larval pools were processed to determine the prevalence of these pathogens in questing I. ricinus from that region. Additionally, Dermacentor marginatus, Dermacentor reticulatus, Ixodes frontalis and Ixodes acuminatus were individually analysed. The groESL operon as well as the 16S rRNA and msp2 genes of Anaplasma were analysed. Similarly, piroplasms were identified at the 18S rRNA gene and the ITS1 of Babesia spp. and Theileria spp. Babesia venatorum (1.5%), A. phagocytophilum (0.7%), Babesia microti (0.3%) and Theileria sp. OT3 (0.2%) were detected in I. ricinus. A single I. frontalis (8.3%) tested positive to A. phagocytophilum. Although a low percentage of I. ricinus were infected with A. phagocytophilum and piroplasms, a potentially human pathogenic variant of A. phagocytophilum was detected, and both Babesia species found were zoonotic. Since the vector of Theileria sp. OT3 remains unknown, further investigations are needed to unravel the role of I. ricinus in the transmission of this piroplasm., (© 2020 The Royal Entomological Society.)

This study evaluated ticks and tick-borne agents in 104 captures of the maned wolf Chrysocyon brachyurus (50 different individuals and 54 recaptures) in the Serra da Canastra National Park (SCNP), a Cerrado preserved area in southeastern Brazil, from 2005 to 2012. From the 104 capture events, a total of 1,206 ticks were collected on 94 occasions (90.4 %), and identified into five species: Amblyomma tigrinum (77.3 % of all collected ticks), Amblyomma sculptum (16.6 %), Amblyomma ovale (0.1 %), Amblyomma brasiliense (0.1 %), Rhipicephalus microplus (0.1 %), and Amblyomma spp. larvae (5.8 %). Molecular analyses of A. tigrinum adult ticks revealed the presence of 'Candidatus Rickettsia andeanae', Rickettsia parkeri sensu stricto, two different haplotypes of 'Ca. Midichloria sp.', and a Hepatozoon canis haplotype. Molecular analyses of maned wolf blood samples revealed two distinct haplotypes of Hepatozoon spp., one identical to the H. canis genotype that was detected in the A. tigrinum ticks, and a Hepatozoon americanum-like haplotype. None tick or blood samples yielded amplicons through PCR assays targeting the genera Ehrlichia, Anaplasma, Babesia, Rangelia, Cytauxzoon, and Theileria. Maned wolf serum samples were tested by immunofluorescence assay against antigens of five Rickettsia species (R. parkeri, R. rickettsii, R. amblyommatis, R. rhipicephali, and R. bellii) and Ehrlichia canis. Among 78 serum samples (45 captures plus 33 recaptures), 74 (95 %) were reactive to at least one Rickettsia species, with R. parkeri eliciting the highest endpoint titers. Some maned wolves that were recaptured during the study were shown to seroconvert to R. parkeri. Serum-reactiveness to E. canis was detected in 36 % (16/45) maned wolves. During the study, general clinical signs of tick-borne diseases were not found in any of the captured animals, indicating that they were under a good health status in the SCNP, despite of been exposed to ticks (mostly A. tigrinum) and some tick-borne agents (Rickettsia, Hepatozoon, Ehrlichia). The results of the present study might represent baseline data for the conservation of the maned wolf in its natural habitat, which should be used to interpret further studies about ticks and tick-borne diseases in maned wolves within human-modified landscapes., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

In order to control the spread of the huanglongbing (HLB) disease in citrus plants, one of the main approaches is management of its vector, the Asian citrus psyllid, Diaphorina citri Kuwayama. The intensive use of chemicals to control the psyllid has caused concern due to the damage to the environment and human health, and biological control has been a more sustainable and environmentally safe strategy. For D. citri, the parasitoid wasp Tamarixia radiata Waterston has been used successfully in the state of São Paulo, Brazil, reducing populations of D. citri nymphs by up 80% in some municipalities. Mass rearing of wasps is required to provide efficient control, which implies that quality control is required, especially in storage and transportation. In most cases, the insects are not used on the same day of emergence, which makes it necessary to develop strategies to delay development without negatively affecting the wasps. Here, we evaluated the survival of T. radiata adults over eight different exposure times (2, 4, 6, 8, 10, 12, 14, and 16 days) in three different temperatures (7, 9, and 11°C). After these periods, they were transferred to climate chambers at 25°C and their survival curves over 30 days were analyzed. We concluded that adults can be maintained at 9°C for up to 6 days without significant damage to their survival during and after the exposure period, functioning well for D. citri IPM implementation.

Seasonal migration of birds between breeding and wintering areas can facilitate the spread of tick species and tick-borne diseases. In this study, 151 birds representing 10 different bird species were captured on Ponza Island, an important migratory stopover off the western coast of Italy and screened for tick infestation. Ticks were collected and identified morphologically. Morphological identification was supported through sequencing a fragment of the 16S mitochondrial gene. In total, 16 captured birds carried ticks from four tick species: Hyalomma rufipes (n = 14), Amblyomma variegatum (n = 1), Amblyomma sp. (n = 1), and Ixodes ventalloi (n = 2). All specimens were either larvae (n = 2) or nymphs (n = 16). All ticks were investigated for tick-borne pathogens using published molecular methods. Rickettsia aeschlimannii was detected in six of the 14 collected H. rufipes ticks. Additionally, the singular A. variegatum nymph tested positive for R. africae. In all 14 H. rufipes specimens (2 larvae and 12 nymphs), Francisella-like endosymbionts were detected. Four H. rufipes ticks tested positive for Borrelia burgdorferi sensu lato in a screening PCR but did not produce sufficient amplicon amounts for species identification. All ticks tested negative for tick-borne encephalitis virus, Crimean-Congo hemorrhagic fever virus, Coxiella burnetii, Coxiella-like organisms, Babesia spp., and Theileria spp. This study confirms the role of migratory birds in the spread and establishment of both exotic tick species and tick-borne pathogens outside their endemic range., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Trypanosomes are blood-borne parasites infecting a range of mammalian hosts worldwide. In Australia, an increasing number of novel Trypanosoma species have been identified from various wildlife hosts, some of which are critically endangered. Trypanosoma noyesi is a recently described species of biosecurity concern, due to a close relationship to the South American human pathogen, Trypanosoma cruzi. This genetic similarity increases the risk for introduction of T. cruzi via a local vector. Unfortunately, there is a lack of knowledge concerning the vectorial capacity of Australian invertebrates for native Trypanosoma species. Australian ixodid ticks (Ixodidae), which are widespread ectoparasites of mammalian wildlife, have received the most attention as likely candidates for trypanosome transmission and have been previously implicated as vectors. However, as all studies to date have focused on blood-fed ticks collected directly from infected mammalian hosts, the question of whether ticks maintain a trypanosome infection between blood meals is unknown. In this study, we investigated the presence of Trypanosoma within 148 Australian adult and nymph questing ticks of the species Amblyomma triguttatum, Ixodes australiensis, Ixodes myrmecobii and larvae Ixodes spp., collected from an endemic region of south-west Australia. Using a novel HRM-qPCR detection method that can discriminate between species of Trypanosoma based on primer melting temperature (T m ), we report the first molecular detection of Trypanosoma DNA in Australian questing ticks, with 6 ticks DNA positive for T. noyesi. Additionally, the presence of intact T. noyesi parasites within all (n = 3) smeared gut and gland contents of questing ticks was confirmed using a fluorescence in situ hybridisation (FISH) assay. Whilst this study was unable to determine the in situ tissue location of trypanosomes for the purpose of discerning a potential route of transmission, these combined molecular and FISH smear data indicate that trypanosomes can persist in ticks between blood meals and that ticks are possibly vectors in the transmission of T. noyesi between native wildlife. Transmission experiments are still required to evaluate the competency of Australian ticks as vectors for T. noyesi. Nevertheless, these novel findings warrant further investigation concerning potential life stages and the development of trypanosomes in both Australian, and other, tick species., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Trombidiformes and Mesostigmata mites, as well as Ixodida ticks, infest ectothermic tetrapods worldwide, potentially acting as vectors of bacteria, viruses and protozoa. The relationship among ectoparasites, transmitted pathogenic agents (e.g., Borrelia spp., Coxiella spp., Hepatozoon spp., and Rickettsia spp.) and ectothermic hosts has been scarcely investigated. This research focuses on a large collection of Brazilian herpetofauna screened for the presence of arthropod ectoparasites and vector-borne microbial agents. Reptiles (n = 121) and amphibians (n = 49) from various locations were infested by ectoparasites. Following genomic extraction, microbial agents were detected in 81 % of the Acari (i.e. n = 113 mites and n = 26 ticks). None of the mites, ticks and tissues from amphibians yielded positive results for any of the screened agents. Blood was collected from reptiles and processed through blood cytology and molecular analyses (n = 48). Of those, six snakes (12.5 %) showed intraerythrocytic alterations compatible with Hepatozoon spp. gamonts and Iridovirus inclusions. Hepatozoon spp. similar to Hepatozoon ayorgbor and Hepatozoon musa were molecularly identified from seven hosts, two mite and two tick species. Rickettsia spp. (e.g., Rickettsia amblyommatis, Rickettsia bellii-like, Rickettsia sp.) were detected molecularly from four mite species and Amblyomma rotundatum ticks. Phylogenetic analyses confirmed the molecular identification of the above-mentioned microbial agents of mites and ticks related to snakes and lizards. Overall, our findings highlighted that the Brazilian herpetofauna and its ectoparasites harbour potentially pathogenic agents, particularly from the northern and south-eastern regions. The detection of several species of spotted fever group Rickettsia pointed out the potential role of ectothermic hosts and related arthropod ectoparasites in the epidemiological cycle of these bacteria in Brazil., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Tickborne diseases are an increasing public health concern in the United States, where the majority of notifiable cases are caused by pathogens vectored by Ixodes ticks. To better monitor changes in acarological risk of human encounters with these ticks and their associated pathogens, the Centers for Disease Control and Prevention (CDC) recently established a national tick and tickborne pathogen surveillance program. Here, we describe and evaluate a new Multiplex PCR Amplicon Sequencing (MPAS) assay for potential use in surveillance programs targeting two common human-biting vector ticks, Ixodes scapularis and Ixodes pacificus. The ability of the MPAS assay to detect five Ixodes-associated human pathogens (Borrelia burgdorferi sensu stricto, Borrelia mayonii, Borrelia miyamotoi, Anaplasma phagocytophilum and Babesia microti) was compared to that of a previously published and routinely used probe-based (TaqMan) PCR testing algorithm for pathogen detection in Ixodes ticks. Assay performance comparisons included a set of 175 host-seeking Ixodes nymphs collected in Connecticut as well as DNA from our pathogen reference collection. The MPAS assay and the CDC standard TaqMan PCR pathogen testing algorithm were found to have equivalent detection sensitivity for Ixodes-associated human pathogens. However, the MPAS assay was able to detect a broader range of tick-associated microorganisms, more effectively detected co-infections of multiple pathogens in a single tick (including different species within the Borrelia burgdorferi sensu lato complex), and required a smaller volume of test sample (thus preserving more sample for future testing)., (Published by Elsevier GmbH.)

Background: The relationship between environmentally transmitted tick parasites, Ixodes spp., and their main reproductive host, deer, is generally thought to be positive. However, measuring host abundance and density directly can be challenging and indirect methods are often used. The observed relationship between the parasite and host may be affected by sampling scale and season, which could lead to different inferences being made. Here, we aimed to test the effect of sampling scale and season on the relationship between density of deer and the density of questing Ixodes ricinus nymphs., Methods: The density of deer (primarily Dama dama) was estimated using line transect distance sampling of deer dung quantified in different seasons (winter and summer) and measured at three different nested scales (site, transect and observation level). Questing nymph density was measured using blanket drag methods and estimates were calculated at the same scales as deer density estimates. General linear models were used to evaluate the relationship between questing nymphs, deer density and other environmental variables at each sampling scale and each season deer density was measured at., Results: While a positive relationship between deer density and questing nymph density was detected at the site and transect scale, no relationship was apparent at the observation level. This was likely due to increased variation and reduced precision of deer dung counts at the finest sampling scale. Seasonal changes in deer populations were observed likely reflecting seasonal shifts in habitat usage. The summer estimates of deer density explained questing nymph density whereas winter estimates did not., Conclusions: Our results show that the scale of sampling can affect the detectability of the positive association between host and vector species. Furthermore, such associations can be obscured if hosts exhibit seasonal changes in habitat use. Thus, both sampling scale and season are important to consider when investigating the relationship between host and vector species.

The Asian longhorned tick, Haemaphysalis longicornis, has recently become established in the United States. In East Asia, Australia, and New Zealand, the native and previously introduced ranges, this tick is a vector of an important pathogen of cattle, Theileria orientalis. In 2017, the pathogenic Ikeda genotype of T. orientalis was associated with cattle mortalities in Virginia and in 2018 the exotic H. longicornis was detected at this same site. To investigate the possible role of this exotic tick in the epidemiology of theileriosis in Virginia, we tested host-seeking H. longicornis for piroplasm infections. We document the detection of exotic Theileria orientalis Ikeda genotype in 12.7 % (15/118) environmentally collected H. longicornis using both the 18S rRNA and major piroplasm surface protein (MPSP) gene targets. This is the first detection of a pathogen in H. longicornis in its introduced range in the United States and offers new insight into the animal health risks associated with the introduction of this exotic tick species to North America., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

The province of Santo Domingo de los Tsáchilas in Ecuador is a strategic place for cattle production and trade. The lack of knowledge about tick species, tick control and tick-borne diseases in Ecuador prompted this study with the goal of identifying the cattle-tick species and tick-borne agents present in the area and molecularly determining the potential acaricide resistance to amitraz of the major cattle tick species. Eighty-four cattle farms were visited and in 88 % of them, cattle were infested with ticks. Additionally, 24 historical samples from other surrounding Ecuadorian provinces, were screened as well. Besides morphological keys, PCR-RFLP MspI was used to confirm the presence of the Rhipicephalus ticks. The tick samples were also screened for tick-borne agents using PCR-RFLP BseDI and Hhal tests to identify circulating Babesia sp. and Anaplasma spp. Furthermore, the PCR-RFLP EciI technique was used to identify the amitraz resistance gene in populations of Rhipicephalus microplus in the province. Pooled testing was used to determine prevalence at individual-tick level. The presence of R. microplus and Amblyomma cajennense sensu lato (s.l.) ticks was found in 83 % and 21 % of the cattle farms respectively, showing R. microplus is widespread in the province of Santo Domingo de los Tsáchilas. Regarding tick-borne agents, only Anaplasma marginale was observed in 50 % of the visited farms of the province, while about 27 % of the ticks tested positive according to estimations from the data of the tick pools. The presence of Babesia bigemina was only confirmed in samples collected outside the province. The amitraz resistance allele in R. microplus was found in 62 % of the farms, but the percentage of farms with cattle ticks completely resistant to this acaricide was low (2%). The findings of this study should prompt cattle producers and animal health authorities to monitor control strategies, which address the management of resistant tick populations and the epidemiologically-unstable areas of tick-borne diseases., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Hyalomma aegyptium (L., 1758) (Ixodida: Ixodidae) is a hard tick and the main host for adults are Palearctic tortoises of the genus Testudo, while larvae and nymphs are less host-specific and nymphs also attach to humans. In the present study, a total of 261 H. aegyptium ticks were removed from 26 Testudo graeca L., 1758 in Corum Province of Turkey. The most prevalent pathogens identified molecularly in the ticks were Hemolivia mauritanica (51.9 %), followed by Rickettsia aeschlimannii (32.6 %), Ehrlichia spp. (30.2 %), and Bartonella bovis (0.8 %). All samples were negative for Coxiella burnetii, Francisella tularensis, Anaplasma phagocytophilum, Babesia spp., Hepatozoon spp. and Theileria spp. Overall, 97.4 % of the examined adult ticks and 26.3 % of nymphs were infected with at least one pathogen, while 40.9 % of all ticks were infected with only one pathogen, 27.4 % with two pathogens, and 9.9 % with three pathogens, concomitantly. Overall, 80.8 % of the examined blood smears of tortoises were H. mauritanica-positive, and the mean intensity of parasitemia was 4.8 % (1-21). As a conclusion, since the examined tortoises were sampled in gardens and vineyards close to human habitation, and as a relatively large percentage of them were infested with ticks carrying pathogenic agents affecting also humans, the importance of tortoises, their ticks and pathogens in terms of the public health should be farther examined., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Plants typically release large quantities of volatiles in response to herbivory by insects. This benefits the plants by, for instance, attracting the natural enemies of the herbivores. We show that the brown planthopper (BPH) has cleverly turned this around by exploiting herbivore-induced plant volatiles (HIPVs) that provide safe havens for its offspring. BPH females preferentially oviposit on rice plants already infested by the rice striped stem borer (SSB), which are avoided by the egg parasitoid Anagrus nilaparvatae , the most important natural enemy of BPH. Using synthetic versions of volatiles identified from plants infested by BPH and/or SSB, we demonstrate the role of HIPVs in these interactions. Moreover, greenhouse and field cage experiments confirm the adaptiveness of the BPH oviposition strategy, resulting in 80% lower parasitism rates of its eggs. Besides revealing a novel exploitation of HIPVs, these findings may lead to novel control strategies against an exceedingly important rice pest., Competing Interests: XH, SS, QL, YJ, YP, YL, TT No competing interests declared, (© 2020, Hu et al.)

As solitary nymphal parasitoids of Paratrioza sinica, the ectoparasitoid Tamarixia lyciumi and the endoparasitoid Psyllaephagus arenarius act as effective biocontrol agents. Thus, it is necessary to facilitate mass productions of both species. Despite showing an excellent parasitic ability, Ps. arenarius is often trapped fatally inside 5th-instar nymphs of Pa. sinica due to strong host immunity. To improve the emergence rate of Ps. arenarius, we evaluated whether Ps. arenarius could utilize T. lyciumi venom via multiparasitism, so the parasitism characteristics of both species were examined between separate-existence (monoparasitism only) and co-existence (mono- and multiparasitism) systems. Further, the parasitism characteristics of Ps. arenarius on venom-injected hosts with/without T. lyciumi eggs were tested to further identify the facilitator. The results showed the parasitism rate of T. lyciumi was increased while that of Ps. arenarius did not change from separate-existence to co-existence systems. The intrinsic performances of two species in monoparasitism did not differ between separate- and co-existence systems. From monoparasitism (separate-existence) to multiparasitism (co-existence), no differences were detected in the intrinsic performances of T. lyciumi, but those of Ps. arenarius were greatly improved. After T. lyciumi venom injection, the parasitism characteristics of Ps. arenarius did not differ between venom-injected hosts with T. lyciumi eggs and those without, further indicating Ps. arenarius benefited from the venom of T. lyciumi females rather than T. lyciumi egg/larval secretions. Instead of negative effects, multiparasitism with ectoparasitoids improves endoparasitoids due to ectoparasitic venom. The study increases host resource utilization and provides creative ways for mass production of endoparasitoids., (© 2019 Institute of Zoology, Chinese Academy of Sciences.)

The risk of contracting babesiosis after a tick bite in Sweden and on the Åland Islands, Finland, is unknown. We investigated clinical and serological outcomes in people bitten by Ixodes ricinus ticks positive for Babesia species. Ticks, blood and questionnaires were obtained from study participants in Sweden and on the Åland Islands. Sixty-five of 2098 (3.1 %) ticks were positive by real-time PCR. Three Babesia species were detected, Babesia microti (n = 33), B. venatorum (n = 27) and B. capreoli (n = 5), the latter species not known to cause human infection. Half (46 %) of the Babesia PCR-positive ticks also contained Borrelia spp. Fifty-three participants bitten by a Babesia PCR-positive tick and a control group bitten by a Babesia PCR-negative tick were tested for B. microti IgG antibodies by IFA. The overall seroprevalence was 4.4 %, but there was no significant difference between the groups. None of the participants seroconverted and no participant with a Babesia PCR-positive tick sought medical care or reported symptoms suggestive of babesiosis. Given the prevalence of Babesia in I. ricinus ticks in southern Sweden and on the Åland Islands, babesiosis should be considered a possible diagnosis in symptomatic residents who seek medical care following tick exposure., (Copyright © 2020 Elsevier GmbH. All rights reserved.)

Triatomine bugs carry the parasitic protozoa Trypanosoma cruzi, the causal agent of Chagas disease. It is known that both the parasite and entomopathogenic fungi can decrease bug survival, but the combined effect of both pathogens is not known, which is relevant for biological control purposes. Herein, the survival of the triatomine Meccus pallidipennis (Stal, 1872) was compared when it was coinfected with the fungus Metarhizium anisopliae (Metschnikoff) and T. cruzi, and when both pathogens acted separately. The immune response of the insect was also studied, using phenoloxidase activity in the bug gut and hemolymph, to understand our survival results. Contrary to expectations, triatomine survival was higher in multiple than in single challenges, even though the immune response was lower in cases of multiple infection. We postulate that T. cruzi exerts a protective effect and/or that the insect reduced the resources allocated to defend itself against both pathogens. Based on the present results, the use of M. anisopliae as a control agent should be re-considered.

Background: Triatomine bugs are responsible for the vectorial transmission of the parasite Trypanosoma cruzi, etiological agent of Chagas disease, a zoonosis affecting 10 million people and with 25 million at risk of infection. Several triatomine species of the genus Rhodnius have been found inhabiting palm crowns where insects can find shelter in leaves axils and blood from palm-associated vertebrates. Rhodnius prolixus insects have been collected in oil palms in Colombia, and high T. cruzi infection rates were found. Since pest control is carried out in oil palm plantations, continuous exposure to insecticides could be occurring in these triatomines. Some insecticides suggested for pest control in oil palm plantations are also recommended for triatomine control in human dwellings. In this study, our objective was to assess if triatomines inhabiting oil palms exhibit resistance to deltamethrin, an insecticide used for vector control., Methods: Rhodnius prolixus nymphs were sampled in oil palms located in Tauramena, Colombia. To determine deltamethrin resistance, biological and biochemical assays were carried out on fifth-instar nymphs from the F1 generation. For biological assays, pure and commercial deltamethrin were used, and in biochemical assays, activities of detoxifying enzymes related to pyrethroid resistance, such as oxidases, esterases and transferases, were quantified., Results: Deltamethrin lethal dosage 50 and 90 in R. prolixus from oil palms was significantly higher than in those from a susceptible colony suggesting possible deltamethrin resistance. Moreover, mortality with commercial deltamethrin was very low in insects from oil palms. In biochemical assays, the activity of evaluated detoxifying enzymes was significantly higher in R. prolixus from oil palms than in those from the susceptible colony., Conclusions: Possible deltamethrin resistance found in R. prolixus insects from oil palms could threaten traditional vector control strategies in urban settings if insecticide-resistant triatomines can migrate from oil palms plantations. In palm oil producer countries such as Colombia, the oil palm plantations are growing constantly during the last years. We suggest that pest control strategies in oil palm crops should include triatomine surveillance and toxicological monitoring, especially in zones with several Chagas disease cases.

Here we describe the new trypanosomatid, Phytomonas borealis sp. n., from the midgut of the spiked shieldbugs, Picromerus bidens (Linnaeus), collected in two locations, Novgorod and Pskov Oblasts of Russia. The phylogenetic analyses, based on the 18S rRNA gene, demonstrated that this flagellate is a sister species to the secondary monoxenous Phytomonas nordicus Frolov et Malysheva, 1993, which was concurrently documented in the same host species in Pskov Oblast. Unlike P. nordicus, which can complete its development (including exit to haemolymph and penetration into salivary glands) in Picromerus bidens, the new species did not form any extraintestinal stages in the host. It also did not produce endomastigotes, indispensable for transmission in other Phytomonas spp. These observations, along with the fact that P. bidens overwinters at the egg stage, led us to the conclusion that the examined infections with P. borealis were non-specific. Strikingly, the flagellates from the Novgorod population contained prokaryotic endosymbionts, whereas the parasites from the second locality were endosymbiont-free. This is a first case documenting presence of intracellular symbiotic bacteria in Phytomonas spp. We suggest that this novel endosymbiotic association arose very recently and did not become obligate yet. Further investigation of P. borealis and its intracellular bacteria may shed light on the origin and early evolution of endosymbiosis in trypanosomatids.

Elevated concentrations of atmospheric CO 2 can alter plant secondary metabolites, which play important roles in the interactions among plants, herbivorous insects and natural enemies. However, few studies have examined the cascading effects of host plant secondary metabolites on tri-trophic interactions under elevated CO 2 (eCO 2 ). In this study, we determined the effects of eCO 2 on the growth and foliar phenolics of Medicago truncatula and the cascading effects on two color genotypes of Acyrthosiphon pisum (pink vs. green) and their parasitoid Aphidius avenae in the field open-top chambers. Our results showed that eCO 2 increased photosynthetic rate, nodule number, yield and the total phenolic content of M. truncatula. eCO 2 had contrasting effects on two genotypes of A. pisum; the green genotype demonstrated increased population abundance, fecundity, growth and feeding efficiency, while the pink genotype showed decreased fitness and these were closely associated with the foliar genstein content. Furthermore, eCO 2 decreased the parasitic rate of A. avenae independent of aphid genotypes. eCO 2 prolonged the emergence time and reduced the emergence rate and percentage of females when associated with the green genotype, but little difference, except for increased percentage of females, was observed in A. avenae under eCO 2 when associated with the pink genotype, indicating that parasitoids can perceive and discriminate the qualities of aphid hosts. We concluded that eCO 2 altered plant phenolics and thus the performance of aphids and parasitoids. Our results indicate that plant phenolics vary by different abiotic and biotic stimuli and could potentially deliver the cascading effects of eCO 2 to the higher trophic levels. Our results also suggest that the green genotype is expected to perform better in future eCO 2 because of decreased plant resistance after its infestation and decreased parasitic rate., (© 2018 Institute of Zoology, Chinese Academy of Sciences.)

Ixodes scapularis is currently known to transmit 7 pathogens responsible for Lyme disease, anaplasmosis, babesiosis, tick-borne relapsing fever, ehrlichiosis, and Powassan encephalitis. Ixodes scapularis can also be colonized by endosymbiotic bacteria including those in the genus of Rickettsia . We screened 459 I. scapularis ticks submitted to the Connecticut Agricultural Experiment Station Tick Testing Laboratory with the objectives to (1) examine differences in infection prevalence of Borrelia burgdorferi , Anaplasma phagocytophilum , Babesia microti , and Borrelia miyamotoi , (2) evaluate whether prevalence of co-infections occur at the same frequency that would be expected based on single infection, and (3) determine the presence of rickettsial endosymbionts in I. scapularis . The prevalence of infection in I. scapularis was highest with Bo. burgdorferi sensu lato (nymph = 45.8%; female = 47.0%), followed by A. phagocytophilum (nymph = 4.0%; female = 6.9%), Ba. microti (nymph = 5.7%; female = 4.7%), and Bo. miyamotoi (nymph = 0%; female = 7.3%). We also identified rickettsial endosymbionts in 93.3% of I. scapularis . Nymphs were significantly more likely to be infected with Bo. burgdorferi if they were infected with Ba. microti , whereas adult females were significantly more likely to be infected with Bo. burgdorferi if they were infected with A. phagocytophilum . Our study suggests that the infection prevalence of Bo. burgdorferi is not independent of other co-circulating pathogens and that there is a substantially higher infection of Bo. miyamotoi in I. scapularis females compared with nymphs in this study. High prevalence of infection and co-infection with multiple pathogens in I. scapularis highlights the public health consequences in Connecticut, a state endemic for Lyme and other tick-borne diseases.

The different components of the mouthparts of hard ticks (Ixodidae) enable these parasites to penetrate host skin, secrete saliva, embed, and suck blood. Moreover, the tick's mouthparts represent a key route for saliva-assisted pathogen transmission as well as pathogen acquisition from blood meal during the tick feeding process. Much has been learned about the basic anatomy of the tick's mouthparts and in the broad outlines of how they function in previous studies. However, the precise mechanics of these functions are little understood. Here, we propose for the first time an animated model of the orchestration of the tick mouthparts and associated structures during blood meal acquisition and salivation. These two actions are known to alternate during tick engorgement. Specifically, our attention has been paid to the mechanism underlining the blood meal uptake into the pharynx through the mouth  and how ticks prevent mixing the uptaken blood with secreted saliva. We animated function of muscles attached to the salivarium and their possible opening /closing of the salivarium, with a plausible explanation of the movement of saliva within the salivarium and massive outpouring of saliva.

Nosema maddoxi Becnel, Solter, Hajek, Huang, Sanscrainte, & Estep, a microsporidian species native to the United States, has been found infecting the invasive brown marmorated stink bug, Halyomorpha halys (Stål). Microsporidian infections in insects often shorten lifespans, decrease fecundity, prolong development, and stunt growth. This study was conducted to determine the impact of N. maddoxi on H. halys fitness. Adult females (2 doses) and nymphs (1 dose) drank suspensions of N. maddoxi spores to promote infection. Adult females receiving a high dose died faster than the controls. Nosema maddoxi infections impacted female egg production and egg viability at both doses compared with the controls. Infections were transmitted to 34.9% of adult males caged with infected females. As the number of days after inoculation increased, infection intensity (# spores found within an infected individual) for both adult treatments transitioned from low-intensity to high-intensity. Infected nymphs died significantly sooner than the controls. Of the treated nymphs, 55.9% died before molting into the fourth instar and only 26.5% eclosed to adults. Nymphal development rate and size were not impacted by N. maddoxi infection. These results indicate that N. maddoxi infection can negatively impact the lifespan of adult females, female fecundity, egg viability, and nymphal survival, which we hypothesize would negatively impact H. halys population densities., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Ixodiphagus hookeri (Hymenoptera: Encyrtidae) is a parasitoid wasp specialized in parasitizing the larvae and nymphs of ticks (Acari: Ixodidae). As parasitized ticks die prior to reproduction, I. hookeri is seen as a prime biological control agent candidate. Despite this, little is known of their occurrence or ecology in northern Europe. The main aim of the current study was to determine whether adult wasps or parasitized ticks can be found from a tick-infested island in southwestern Finland, using field collections and molecular methods. Following the initial discovery of an adult I. hookeri female on Seili Island, we set out to collect further specimens via sweep netting and Malaise trappings between May and October 2017. Furthermore, 1310 Ixodes ricinus (1220 nymphs, 90 adults) collected from the island during 2012-2014 were screened for I. hookeri DNA using qPCR. Whereas no further wasp specimens could be collected via sweep netting or Malaise trappings, I. hookeri DNA was consistently detected in I. ricinus nymphs (annual minimum infection rates in 2012, 2013, and 2014: 2.3, 0.4, and 0.5%, respectively), whereas all adult samples were negative. Although the annually repeated detections of parasitized ticks suggest that the wasp inhabits the island, further field and molecular surveys are needed to more comprehensively determine the status and stability of the population.

The aim of this study was to investigate the foraging behavior of Aphidius matricariae (Haliday) (Hymenoptera: Braconidae) as a biological control agent of Myzus persicae nicotianae Blackman (Hemiptera: Aphididae), a key and cosmopolitan pest of tobacco fields. To achieve a strategy for the control of this pest and a mass-rearing program of the parasitoid, host stage preference, switching, functional response, and mutual interference of A. matricariae were investigated at 25 ± 1°C, 70 ± 5% RH and 16:8 h L:D photoperiod. The parasitoid showed a preference for third- and fourth-instar nymphs of tobacco aphid in both choice and no-choice experiments. Using the Murdach's model, switching behavior was observed in A. matricariae between different density proportions of third- and fourth-instar nymphs. Further, the parasitoid exhibited a type II functional response when it was offered to third-instar nymphs of M. persicae nicotianae at six densities (2, 4, 8, 16, 32, and 64). Based on the linear regression analysis, there was a significance difference between the logarithm of per capita searching efficiency and the logarithm of parasitoid density. As the wasp density increased, per capita searching efficiency decreased. The result of this study revealed that A. matricariae is an effective agent in the integrated management of M. persicae nicotianae. In addition, application of these results can be important in mass-rearing program of A. matricariae.

Fifty nymphal Ixodes ricinus ticks collected in Alsace, France, identified by morphological criteria and using MALDI-TOF MS, were tested by PCR to detect tick-associated bacteria and protozoan parasites. Seventy percent (35/50) of ticks contained at least one microorganism; 26% (9/35) contained two or more species. Several human pathogens were identified including Borrelia burgdorferi s.s. (4%), Borrelia afzelii (2%), Borrelia garinii (2%), Borrelia valaisiana (4%), Borrelia miyamotoi (2%), Rickettsia helvetica (6%) and "Babesia venatorum" (2%). Bartonella spp. (10%) and a Wolbachia spp. (8%) were also detected. The most common co-infections involved Anaplasmataceae with Borrelia spp. (4%), Anaplasmataceae with Bartonella spp. (6%) and Anaplasmataceae with Rickettsia spp. (6%). Co-infection involving three different groups of bacteria was seen between bacteria of the family Anaplasmataceae, Borrelia spp. and Bartonella spp. (2%). Results highlight the panel of infectious agents carried by Ixodes ricinus. Co-infection suggests the possibility of transmission of more than one pathogen to human and animals during tick blood feeding., (Copyright © 2019 Elsevier GmbH. All rights reserved.)