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European earwig, Forficula auricularia L. sensu lato (Dermaptera: Forficulidae), is a univoltine, resident, omnivorous species and a beneficial predator in pome fruit orchards. Here, three methods were used to investigate pear (Pyrus communis L., Rosaceae) orchard inoculation with European earwig for biocontrol of pear psylla, Cacopsylla pyricola (Foerster) (Hemiptera: Psyllidae), in Washington State, USA. The first method was earwig inoculation experiments. In a first experiment (2019–2020), each of three orchards had one inoculation and one control plot. In a second experiment (2020–2021), there were four inoculation and four control plots in each of the same three orchards. In both experiments, earwigs persisted during the year of inoculation, but earwigs were nearly absent the following season at two orchards that used conventional broad‐spectrum pesticides. At the third orchard, which excluded broad‐spectrum pesticides under an integrated pest management (IPM) program, earwigs became abundant in year two of the second experiment. The second method was case studies. In the first of two case studies, during 2016, 2017, 2022, and 2023, in half of the integrated orchard from above, conventional broad‐spectrum sprays were used. Earwig populations became low in the conventional half. In the second case study, earwigs became abundant after inoculation of an integrated orchard by the grower. Earwigs spread to the edge of the orchard in year two and spilled into a neighboring orchard in years three and four. The third method was an observational study of 36 pear orchards over 5 years. Earwigs were rarely found in conventionally sprayed orchards, and earwigs increased each additional year integrated management was used. The findings suggest conventional pear spray programs in Washington nearly eradicate earwigs, but populations can recover under integrated management with natural dispersal from refuges or with inoculative releases. [ABSTRACT FROM AUTHOR]

A new genus and species of fossil whiteflies (Aleyrodidae) and a psyllid (Psyllidae) were discovered in the Hindon Maar Complex, a Fossil-Lagerstätte within the Dunedin Volcanic Group in Otago, South Island of New Zealand. These represent the first fossil records of these sternorrhynchan families (Hemiptera) from New Zealand. Miotetraleurodes novaezelandiae gen. et sp. nov., is described from specimens of puparia attached to angiosperm leaves. It is assigned to the subfamily Aleyrodinae and represents the first fossil whitefly from New Zealand and the third genus known from puparia globally. The forewing of a psyllid (Psyllidae: Hemiptera) was found in the same stratum, and represents the first fossil record of any fossil taxa of the superfamily Psylloidea in New Zealand. [ABSTRACT FROM AUTHOR]

Boxwood (Buxus sempervirens) is a host for several mite and insect pests, but the species of plant-parasitic psyllid Spanioneura fonscolombii has been observed in Romania for the first time in 2017. Subsequent research has shown that the species is much more spread, our data confirming its presence in western, eastern, and southern Romania. This is also the most south-eastern record of the species in Europe.

The psyllid Aphalara itadori Shinji (Hemiptera: Psyllidae) is a biocontrol agent against invasive knotweed species (Polygonaceae) in Europe and North America. Despite an extensive release program, successful establishment of the agent has never been confirmed. The slow establishment of A. itadori in its introduced range appears to be predominantly the result of nymphal mortality, either through desiccation, predation, or the adaptation of captive populations to low‐stress environments. In 2016, CABI UK collected a new line of psyllids from Murakami, Niigata Prefecture, in Japan, where it was observed causing severe leaf‐roll galling on one of the many varieties of native knotweeds. The induction of leaf‐roll galls by Murakami psyllids on invasive Bohemian knotweed, Reynoutria × bohemica, has the potential to alleviate some or all of the observed nymphal mortality factors. We conducted a series of growth chamber experiments to explore the psyllid behaviors that initiate leaf‐roll galls, and the ways in which the galls might benefit the psyllids and inhibit invasive knotweed. Reynoutria × bohemica exposed to A. itadori for 4 weeks suffered reduced stem elongation and leaf area compared to control plants. Artificial leaf‐roll galls were consistently utilized by developing A. itadori nymphs, and contributed to their survival. Leaf‐roll galling in R. × bohemica was predominantly initiated by early instar nymphs of A. itadori, and only occurred when leaves were attacked at a very early stage in their development. Our results can inform the knotweed biocontrol program in several key ways. Releases of A. itadori should be timed so that developing nymphs have access to newly emerging leaves. Monitoring efforts at release sites should focus on the growing tips of R. × bohemica, where the highly mobile nymphs appear to migrate. Finally, our results provide motivation to seek additional lines of A. itadori that may affect other invasive knotweed species in similar ways. [ABSTRACT FROM AUTHOR]

The bacterial pathogen Candidatus Liberibacter asiaticus (CLas) is the causal agent of citrus greening disease. This unusual plant pathogenic bacterium also infects its psyllid host, the Asian citrus psyllid (ACP). To investigate gene expression profiles with a focus on genes involved in infection and circulation within the psyllid host of CLas, RNA-seq libraries were constructed from CLas-infected and CLas-free ACP representing the five different developmental stages, namely, nymphal instars 1-2, 3, and 4-5, and teneral and mature adults. The Gbp paired-end reads (296) representing the transcriptional landscape of ACP across all life stages and the official gene set (OGSv3) were annotated based on the chromosomal-length v3 reference genome and used for de novo transcript discovery resulting in 25,410 genes with 124,177 isoforms. Differential expression analysis across all ACP developmental stages revealed instar-specific responses to CLas infection, with greater overall responses by nymphal instars, compared to mature adults. More genes were over-or under-expressed in the 4-5th nymphal instars and young (teneral) adults than in instars 1-3, or mature adults, indicating that late immature instars and young maturing adults were highly responsive to CLas infection. Genes identified with potential for direct or indirect involvement in the ACP-CLas circulative, propagative transmission pathway were predominantly responsive during early invasion and infection processes and included canonical cytoskeletal remodeling and endo-exocytosis pathway genes. Genes with predicted functions in defense, development, and immunity exhibited the greatest responsiveness to CLas infection. These results shed new light on ACP-CLas interactions essential for pathogenesis of the psyllid host, some that share striking similarities with effector protein-animal host mechanisms reported for other culturable and/or fastidious bacterial- or viral-host pathosystems. [ABSTRACT FROM AUTHOR]

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is the major citrus pest worldwide because it can transmit the bacteria associated with citrus greening disease (huanglongbing, HLB). The most common management strategy of this pest is chemical control, but this often results in pest resistance and threatens the sustainability of the citrus culture. There is therefore need for sustainable control strategies such as biological control. Previous experiments showed that the predatory mite Amblyseius herbicolus Chant (Acari: Phytoseiidae) is able to develop and reproduce on D. citri eggs. Here, we studied the population dynamics of this pest on plants with and without A. herbicolus on isolated orange jasmine plants, Murraya paniculata (L.) Jack (Rutaceae), an important host plant of the pest. Predatory mites were released 1 week before the release of D. citri and were provided with twines with pollen as oviposition sites and food source, respectively, to maintain populations of A. herbicolus in the absence of the pest. Densities of adults and nymphs of D. citri on plants with predators were about 85% lower than on plants without predators, showing that A. herbicolus is a potential biocontrol agent of D. citri. However, the stage structure of the D. citri populations at the end of the experiment did not differ significantly between control plants and plants with predators. This led us to investigate whether the predator attacked other stages besides eggs. Indeed, predators were able to feed and reproduce on first and second instar nymphs of D. citri, but not on instars 3–5. Concluding, the release of A. herbicolus with alternative food and oviposition sites can reduce infestations of D. citri. We suggest that field experiments should be done in areas where HLB occurs to test whether releases of this predator limit the spread of this devastating disease. [ABSTRACT FROM AUTHOR]

The Psylloidea, >4000 named species known today, are plant-feeding, sap-sucking insects sleeved under the Sternorrhyncha. Most species of Psylloidea are confined to the tropics. They occur as gall-inducing, free-living, and lerp-forming taxa. Lifecycles and generations of gall-inducing Psylloidea vary in temperate and tropical worlds. The Triozidae, Aphalaridae, and Calophyidae include several taxa that induce galls of diverse morphologies, from simple pits and leaf-margin rolls to complex pouches and of two-tier structures. The feeding mechanism and nutritional physiology of the gall-inducing taxa of the Psylloidea differ from those of the free-living and lerp-forming species. A majority of the gall-inducing Psylloidea are associated with the dicotyledons and a small number with the monocotyledons. The gall-inducing Psylloidea are specific to certain plants. Their host specificity is regulated by specific lipids and sterols. The gall-inducing Psylloidea show conservative behavior in terms of geographical distribution. Although the life histories of several gall-inducing Psylloidea are known today, aspects explaining their association with host plants are little known. Details of nutritional physiology of gall-inducing Psylloidea are less known presently compared with that of the free-living species. A better understanding of the association and level of relationship between gall-inducing Psylloidea and their host plants is necessary.

Boxwood (Buxus sempervirens) is a host for several mite and insect pests, but the species of plant-parasitic psyllid Spanioneura fonscolombii has been observed in Romania for the first time in 2017. Subsequent research has shown that the species is much more spread, our data confirming its presence in western, eastern, and southern Romania. This is also the most south-eastern record of the species in Europe. [ABSTRACT FROM AUTHOR]

Reflective groundcovers can improve crop yield and quality and deter pests by increasing light penetration into plant canopies. In pear (Pyrus communis L.) orchards, this could increase profitability and reduce reliance on insecticides to manage pear psylla (Cacopsylla pyricola [Foerster]). Two types of reflective groundcovers, metallized polyethylene film (metallized film) and white geotextile fabric (reflective fabric), are known to increase pear yield and quality, and metallized film was recently reported to suppress pear psylla. Here, we tested reflective fabric for pear psylla suppression at a research orchard in 2019, then we partnered with five pear orchard managers to test metallized film and reflective fabric for pear psylla suppression at five conventional commercial orchards in 2020 and one organic commercial orchard in 2021. There was evidence of pear psylla suppression by both metallized film and reflective fabric, but effects varied among reflective materials, pear psylla life stages, season and year of study. Reflective groundcovers did not affect fruit size, weight, sunburn or pest mite abundance, and they were compatible with pear psylla biocontrol. Low perceived benefit relative to cost was a barrier to continued trialling and adoption. Whereas orchardists in our study used reflective groundcovers in addition to normal pesticide regimes, previous research studies suggest that reflective groundcovers can profitably replace some insecticides. Future studies are needed to test the outcomes of replacing pesticides with reflective groundcovers in commercial orchards and understand under what circumstances they improve pear quality and yield. [ABSTRACT FROM AUTHOR]

Psyllaephagus sp. (Hymenoptera: Encyrtidae) is a newly recognized and important parasitoid of Cacopsylla chinensis (Yang and Li) (Hemiptera: Psyllidae), a pest of pear orchards. Its parasitism potential and rearing were studied in the laboratory. The studies showed that the most suitable hosts were fourth- and fifth-instar nymphs of pear psyllids (C. chinensis). The development duration of Psyllaephagus sp. females and males was 15.25 ± 0.37 and 13.57 ± 0.27 days when laying eggs in fourth-instar psyllid nymphs. The wasps did not survive longer than three days when they were fed only water, while they survived about an average of 20 days (23.20 ± 1.12 for females and 19.00 ± 0.80 for males) when fed 20% honey water. The provision of honey water could thus increase adult parasitoid longevity significantly. The lifetime fecundity of Psyllaephagus sp. females was 21.60 ± 0.88. Tests of parasitoid efficiency showed that the wasp's functional response was Holling type II, with the number of hosts parasitized increasing with the host density to a maximum parasitism rate. The model suggested that a single Psyllaephagus sp. female could parasitize a maximum of 13.66 nymphs per day. The mutual interference of foraging Psyllaephagus sp. females occurred at high parasitoid densities. Psyllaephagus sp. has potential as a biocontrol agent for use against C. chinensis. [ABSTRACT FROM AUTHOR]

The Psylloidea, >4000 named species known today, are plant-feeding, sap-sucking insects sleeved under the Sternorrhyncha. Most species of Psylloidea are confined to the tropics. They occur as gall-inducing, free-living, and lerp-forming taxa. Lifecycles and generations of gall-inducing Psylloidea vary in temperate and tropical worlds. The Triozidae, Aphalaridae, and Calophyidae include several taxa that induce galls of diverse morphologies, from simple pits and leaf-margin rolls to complex pouches and of two-tier structures. The feeding mechanism and nutritional physiology of the gall-inducing taxa of the Psylloidea differ from those of the free-living and lerp-forming species. A majority of the gall-inducing Psylloidea are associated with the dicotyledons and a small number with the monocotyledons. The gall-inducing Psylloidea are specific to certain plants. Their host specificity is regulated by specific lipids and sterols. The gall-inducing Psylloidea show conservative behavior in terms of geographical distribution. Although the life histories of several gall-inducing Psylloidea are known today, aspects explaining their association with host plants are little known. Details of nutritional physiology of gall-inducing Psylloidea are less known presently compared with that of the free-living species. A better understanding of the association and level of relationship between gall-inducing Psylloidea and their host plants is necessary. [ABSTRACT FROM AUTHOR]

Essential oils (EOs) are promising sources of effective bioactive compounds for insect pest control, especially in heavily treated agrosystems like orchards. Plants belonging to the Amaryllidaceae family – onion, garlic (Allium sativum L.), and others – present an interesting potential in apple (Malus domestica Borkh.) and pear (Pyrus communis L., both Rosaceae) tree integrated pest management due to the repellent and deterrent properties of their chemical compounds. This study explores the potential disruption by garlic EOs of the behavior of two hemipteran pests towards their host trees: rosy apple aphid, Dysaphis plantaginea (Passerini) (Aphididae), on cultivated apple, and pear psyllid, Cacopsylla pyri (L.) (Psyllidae), on pear. Effects on orientation and feeding behavior were evaluated using choice tests and the electropenetrography (EPG) technique. The results revealed that garlic EOs delivered through rubber dispensers were intrinsically repellent, but when combined with the attractive host plant, the repellents and attractants canceled each other out for the two studied hemipterans. Garlic EOs caused disruptions in the feeding behavior of the two insects, particularly the psyllids, which showed a decrease in phloem sap intake. This study highlights the mechanisms disrupting the process of host‐plant colonization, in particular the possible masking of host‐locating cues or the involvement of confusing chemical stimuli due to EO volatiles. [ABSTRACT FROM AUTHOR]

Simple Summary: Pear psyllids are responsible for transmitting the pathogen 'Candidatus Phytoplasma pyri', causing the pear decline disease. Specific repellents are a potential method for controlling this pest and reducing the spreading of phytoplasma pear in orchards. Little is known about the chemical ecology of these insects. Based on recent literature, we tested the behavioral reactions of Cacopsylla pyri and Cacopsylla pyricola to the major synthetic compounds of clove essential oil in olfactometer experiments. In addition, we developed new nanofiber-based repellents dispensers and evaluated their repellent and host-odor masking activity in the laboratory and later in the field. Results demonstrate that only the synthetic mixture of the three major compounds of the clove essential was repellent to both psyllids species. When volatiles were formulated in nanofibers, they were not only repellent but could mask the odors of pear plants, disrupting the insects from finding the host. In the field, no differences in psyllids captures were observed in color-attractive sticky traps with repellent-loaded nanofibers or nanofibers without repellent. Our study also evaluated the release rates of volatiles from the nanoformulation. We discussed using nanofibers as volatile dispensers and the improvements necessary to use repellents as a management tool for pear psyllids in the field. Pear psyllids are the main vectors of the pathogen 'Candidatus Phytoplasma pyri' causing pear decline. Based on earlier reports, we tested the behavioral activity of the major synthetic compounds of clove essential oil (eugenol, eugenyl acetate, and β-caryophyllene) against Cacopsylla pyri and C. pyricola. Of six mixtures tested in olfactometer assays, a formulation consisting of three specific compounds (M6 mixture) demonstrated a repellent effect on both psyllid species. In addition, this formulation masked the odor of the host Pyrus communis cv. Williams Christ, disturbing the host finding ability of C. pyri. Electrospun fibers were produced with biocompatible polymers poly(ε-caprolactone), cellulose acetate, and solvents formic acid and acetic acid, loaded with the repellent mixture to test their efficacy as dispensers of repellents in laboratory and field. The fibers produced were repellent to C. pyri and effectively masked the odors of pear plants in olfactometer tests. In a pear orchard, we compared the captures of pear psyllids in green-colored attractive traps treated with nanofibers loaded with M6 mixture or unloaded nanofibers (blank). The result showed no differences in the captures of C. pyri between treatments. The release rates of volatiles from the fibers were evaluated weekly over 56 days. The fibers were able to entrap the major compound of the M6 mixture, eugenol, but the release rates were significantly reduced after 21 days. Our results suggest that biodegradable dispensers could be produced with electrospinning, but further improvements are necessary to use repellents as a management tool for pear psyllids in the field. [ABSTRACT FROM AUTHOR]

Bumblebees are opportunistic resource consumers and have been known to visit extrafloral nectaries and harvest aphid and scale honeydew. We report the first observation of bumblebees foraging psyllid honeydew in a tritrophic system in the boreal forest of Yukon Territory, Canada.In this system, a willow (Salix alaxensis) develops bizarrely enlarged petiole bases which act as nursery cavities for large numbers of psyllid immatures of Cacopsylla macleani (Homoptera: Psyllidae), with later instars dispersing over the underside of the leaf.These immatures produced abundant honeydew which was vigorously and persistently foraged by several bumblebees of multiple species (we identified Bombus vancouverensis, Bombus melanopygus and Bombus mckayi). Ants and vespid wasps were also present but in lower numbers.Salix alaxensis and Salix‐feeding psyllids are common throughout arctic and boreal regions, so honeydew production is potentially a supplementary food source for Bombus when floral nectar flows are limited due to low temperatures or drought. [ABSTRACT FROM AUTHOR]

Improved methods of integrated pest management of the pear psyllid Cacopsylla pyri (L.), the primary pest of pear in Europe and North America, are needed. Trechnites insidiosus (Crawford) is the most abundant parasitoid of C. pyri in pear orchards, where it is present early in the psyllid infestation period. However, little is known about its general biology, interaction with its host and potential as a control agent. The objective of this laboratory study was to evaluate the behaviour of a specialist parasitoid when presented with different larval instars of C. pyri, and assess the quality of the next generation of parasitoids. T. insidiosus was able to insert its ovipositor into all host instars. However, the fourth instar of the host appeared to be the most suitable in terms of behavioural acceptance, time spent walking, antennal activity and progeny development (mummy formation, development time and tibial length). In addition, we report a low frequency of host-feeding behaviour by this parasitoid. From a biological control perspective, we suggest that favouring T. insidiosus, either through mass releases or conservation of naturally present populations, when the first generation of psyllids reach the fourth instar, would maximize the chance of controlling psyllid populations in pear orchards.

Cacopsylla burckhardti Luo, Li, Ma & Cai, 2012 (Hemiptera, Psylloidea, Psyllidae) is a pear psyllid species, distributed in the East Asia. The complete mitogenome of C. burckhardti is obtained in this study for the first time. The mitogenome of C. burckhardti is circular form and 14,798 bp long, which consists of 13 protein-coding genes, 22 tRNAs and two rRNAs. The base composition is 38.80% for A, 34.89% for T, 9.99% for G and 16.33% for C, with the higher A + T contents (73.69%). The phylogenetic analysis, using 13 protein-coding genes, shows that C. burckhardti is clustered with other Cacopsylla species and nested in the Psyllidae clade within the superfamily Psylloidea. [ABSTRACT FROM AUTHOR]

This study investigated the effectiveness of field releases of nymphs of Anthocoris nemoralis (F.) (Hemiptera: Anthocoridae) in controlling the olive psyllid, Euphyllura olivina Costa (Hemiptera: Psyllidae). Field trials were conducted in two successive years (2014 and 2015) in two organic olive orchards located in the region of Sfax (Tunisia) using two treatments: low (release of 10 A. nemoralis nymphs/tree) and high (release of 40 A. nemoralis nymphs/tree) applied two times, the first on March 3 and second on March 17. In both olive orchards, the high treatment was the most effective in controlling the increase of E. olivina in the spring. The A. nemoralis population grew gradually and reached a single peak towards the end of April. In control and low treatment plots, despite the significant increase in predator populations, psylla abundance was not controlled. After the second release, however, in high treatment plots a reduction in psyllid density was recorded. An expected effect of the A. nemoralis releases was a reduced parasitic activity of Psyllaephagus euphyllurae (Masi) (Hymenoptera: Encyrtidae).

Bactericera gobica is the major pest of Goji berry plants and causes severe damage. Psyllids mainly use the antennal sensilla to recognize olfactory cues necessary to find host plants and mates. However, the structure and function of the antenna and the antennal sensilla of B. gobica remains previously unexplored. Here, we identify the external and internal morphology of the antennal sensilla of B. gobica using both scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We found seven types of sensilla on the filiform antennae, including apical setae (LAS, SAS), sensilla basiconica (SB1, SB2), sensilla campaniform (SCA), sensilla chaetica (ChS1, ChS2), cavity sensilla (CvS1, CvS2), antennal rhinaria (AR1, AR2), and sensilla trichodea (ST). Five of these sensilla types--apical setae, sensilla basiconica, sensilla chaetica, cavity sensilla, and antennal rhinaria--may have olfactory functions based on their porous surfaces and internal dendritic outer segments (DOS). We also found several differences between the two sexes of B. gobica in the sensilla array and internal structure. ChS and DOS in the protrusions of AR were more abundant in males than females. Altogether, we comprehensively revealed the fine structure and probable function of B. gobica antennae and identified differences in the distribution and structure between psyllid sexes. Our findings provide important insights for future studies on defining the olfactory function of psyllid antenna using electrophysiological methods. [ABSTRACT FROM AUTHOR]

Psyllaephagus sp. (Hymenoptera: Encyrtidae) is a newly recognized and important parasitoid of Cacopsylla chinensis (Yang and Li) (Hemiptera: Psyllidae), a pest of pear orchards. Its parasitism potential and rearing were studied in the laboratory. The studies showed that the most suitable hosts were fourth- and fifth-instar nymphs of pear psyllids (C. chinensis). The development duration of Psyllaephagus sp. females and males was 15.25 ± 0.37 and 13.57 ± 0.27 days when laying eggs in fourth-instar psyllid nymphs. The wasps did not survive longer than three days when they were fed only water, while they survived about an average of 20 days (23.20 ± 1.12 for females and 19.00 ± 0.80 for males) when fed 20% honey water. The provision of honey water could thus increase adult parasitoid longevity significantly. The lifetime fecundity of Psyllaephagus sp. females was 21.60 ± 0.88. Tests of parasitoid efficiency showed that the wasp’s functional response was Holling type II, with the number of hosts parasitized increasing with the host density to a maximum parasitism rate. The model suggested that a single Psyllaephagus sp. female could parasitize a maximum of 13.66 nymphs per day. The mutual interference of foraging Psyllaephagus sp. females occurred at high parasitoid densities. Psyllaephagus sp. has potential as a biocontrol agent for use against C. chinensis.

Improved methods of integrated pest management of the pear psyllid Cacopsylla pyri (L.), the primary pest of pear in Europe and North America, are needed. Trechnites insidiosus (Crawford) is the most abundant parasitoid of C. pyri in pear orchards, where it is present early in the psyllid infestation period. However, little is known about its general biology, interaction with its host and potential as a control agent. The objective of this laboratory study was to evaluate the behaviour of a specialist parasitoid when presented with different larval instars of C. pyri, and assess the quality of the next generation of parasitoids. T. insidiosus was able to insert its ovipositor into all host instars. However, the fourth instar of the host appeared to be the most suitable in terms of behavioural acceptance, time spent walking, antennal activity and progeny development (mummy formation, development time and tibial length). In addition, we report a low frequency of host-feeding behaviour by this parasitoid. From a biological control perspective, we suggest that favouring T. insidiosus, either through mass releases or conservation of naturally present populations, when the first generation of psyllids reach the fourth instar, would maximize the chance of controlling psyllid populations in pear orchards. [ABSTRACT FROM AUTHOR]

Pear psyllids are the main vectors of the pathogen ‘Candidatus Phytoplasma pyri’ causing pear decline. Based on earlier reports, we tested the behavioral activity of the major synthetic compounds of clove essential oil (eugenol, eugenyl acetate, and β-caryophyllene) against Cacopsylla pyri and C. pyricola. Of six mixtures tested in olfactometer assays, a formulation consisting of three specific compounds (M6 mixture) demonstrated a repellent effect on both psyllid species. In addition, this formulation masked the odor of the host Pyrus communis cv. Williams Christ, disturbing the host finding ability of C. pyri. Electrospun fibers were produced with biocompatible polymers poly(ε-caprolactone), cellulose acetate, and solvents formic acid and acetic acid, loaded with the repellent mixture to test their efficacy as dispensers of repellents in laboratory and field. The fibers produced were repellent to C. pyri and effectively masked the odors of pear plants in olfactometer tests. In a pear orchard, we compared the captures of pear psyllids in green-colored attractive traps treated with nanofibers loaded with M6 mixture or unloaded nanofibers (blank). The result showed no differences in the captures of C. pyri between treatments. The release rates of volatiles from the fibers were evaluated weekly over 56 days. The fibers were able to entrap the major compound of the M6 mixture, eugenol, but the release rates were significantly reduced after 21 days. Our results suggest that biodegradable dispensers could be produced with electrospinning, but further improvements are necessary to use repellents as a management tool for pear psyllids in the field.

Diaphorina citri Kuwayama (Hemiptera, Psyllidae) ou psilídeo-dos-citros, inseto exótico que se alimenta nas brotações das plantas cítricas, causa o encrespamento das folhas, reduz a produção de frutas e é o vetor da bactéria Candidatus Liberibacter, agente causal do “greening”. A sua excreção favorece a colonização pelo fungo Capinodium citri Berk & Desm., que causa a fumagina nas plantas. Infestação deste psilídeo foi observada em um pomar de citros localizado em Chapecó, em outubro de 2004, sendo o primeiro relato da sua ocorrência no Estado de Santa Catarina.

This study investigated the effectiveness of field releases of nymphs of Anthocoris nemoralis (F.) (Hemiptera: Anthocoridae) in controlling the olive psyllid, Euphyllura olivina Costa (Hemiptera: Psyllidae). Field trials were conducted in two successive years (2014 and 2015) in two organic olive orchards located in the region of Sfax (Tunisia) using two treatments: low (release of 10 A. nemoralis nymphs/tree) and high (release of 40 A. nemoralis nymphs/tree) applied two times, the first on March 3 and second on March 17. In both olive orchards, the high treatment was the most effective in controlling the increase of E. olivina in the spring. The A. nemoralis population grew gradually and reached a single peak towards the end of April. In control and low treatment plots, despite the significant increase in predator populations, psylla abundance was not controlled. After the second release, however, in high treatment plots a reduction in psyllid density was recorded. An expected effect of the A. nemoralis releases was a reduced parasitic activity of Psyllaephagus euphyllurae (Masi) (Hymenoptera: Encyrtidae). [ABSTRACT FROM AUTHOR]

Fluorescence in situ hybridization (FISH) is a technique used to determine the chromosomal position of DNA and RNA probes. The present study contributes to knowledge on jumping plant-lice genomes by using FISH with 18S rDNA and telomeric (TTAGG)n probes on meiotic chromosomes of Psylla alni (2n = 24 + X), Cacopsylla mali (2n = 22 + neo-XY and 20 + neo-X1X2Y), C. sorbi (2n = 20 + neo-XY), Baeopelma foersteri (2n = 14 + X), and Rhinocola aceris (2n = 10 + X). This is the first study that has used FISH on the hemipteran superfamily Psylloidea. We found that the chromosomes of all studied species contain the insect-type telomere motif, (TTAGG)n. In C. mali and C. sorbi, the neo-sex chromosomes originating from autosome-sex chromosome fusions showed no interstitially located clusters of TTAGG repeats, suggesting their loss or inactivation. Similarly, no interstitial (TTAGG)n clusters were detected in an extremely large autosome pair of B. foersteri that most likely originated from a fusion of at least five ancestral chromosome pairs. Clusters of 18S rDNA were detected on the fused and second largest autosome pairs of B. foersteri and on one of the large autosome pairs of the remaining species. In C. mali and B. foersteri, the rDNA clusters were shown to coincide with the NORs as detected by the AgNOR method. Finally, we speculate, based on the obtained FISH markers, on the mechanisms of karyotype evolution of psylloid species differing in chromosome numbers and sex chromosome systems.

The occurrence of biological stages and population fluctuation of Euphyllura phillyreae Foerster (Hem.: Psyllidae) on Memecik olive trees (Olea europaea L. cv. Memecik) in Bornova and Kemalpaşa districts (İzmir) were investigated during the years of 2015-2016. The eggs of E. phillyreae in olive groves were found between 8 March-12 May and its nymphs between 16 March and 18 June. The first eggs laid during the formation period of flower clusters and at the beginning of budding period in Bornova were seen 2-3 weeks before Kemalpaşa. Egg and nymph stages were only appeared between early March till middle of June. The average temperatures of March, April and May respectively were: 11.9/14.9/22.6 °C in Bornova, 9.6/12.6/20.2 °C in Kemalpaşa in 2015; and it was 13.4/18.2/21.2 °C in Bornova, 11.0/16.9/18.4 °C in Kemalpaşa in 2016. The number of nymphs reached highest level in the last week of April. Also, in both years, nymphs were seen in Bornova until the third week of June (medium-large green fruit period) and until the end of May (fruit set period) in Kemalpaşa. Adults were collected from olive groves throughout the year. Although it changes over the years, new adults firstly emerged during the closed flower bud, flower bud opening, beginning of flowering or 50% flowering periods of olive trees between 28 April and 29 May. It was determined that the adult population was higher during the summer months and then gradually decreased. The lowest adult numbers were obtained in January and February. It was concluded that E. phillyreae was univoltine in Izmir. [ABSTRACT FROM AUTHOR]

A fossil specimen of the jumping plant-louse genus Cacopsylla (Insecta, Hemiptera, Psylloidea) is described from lacustrine sediments of the middle Pleistocene Miyajima Formation of the Shiobara Group in Tochigi Prefecture, central Japan. It is the first report of a psylloid fossil from Japan. The specimen is a compression fossil of almost whole insect body, and the superb preservation of forewings with delicate veins and membrane tissues strongly suggests that it can be most probably identified as Cacopsylla abieti (Kuwayama), which is a common extant psyllid species in the fossil locality, or possibly its most closely relative of continental east Asia, Cacopsylla pseudosieboldiani (Konovalova and Loginova). The fossil-yielding stratum is a Lagerstätte known for the abundant fossil leaves and other fossil organisms. Extant C. abieti feeds on Siebold's maple Acer sieboldianum, and remains of various species of Acer including A. sieboldianum are common components of Shiobara fossil biota. [ABSTRACT FROM AUTHOR]

Psyllids are oligophagous phytophagous insects with many specialist willow (Salix spp.) feeding species in two genera (Cacopsylla and Bactericera). We examine the patterns of distribution and co-occurrence of willow-feeding species at 42 willow sites across Europe forming a transect from Greece (lat. 38.8 °N) to arctic Norway (lat. 70.6 °N). The transect and sites have been described in previous papers. [ABSTRACT FROM AUTHOR]

Increases in the frequency and duration of droughts under global climate change could have implications for plant–insect interactions, and could either increase or decrease the effects of weed biological control agents. In this study, we used greenhouse and field experiments to examine the impacts of drought stress on the abundance and impacts of the adventive psyllid Arytainilla spartiophila Forster (Hemiptera: Psyllidae, Arytaininae) on its target weed Scotch broom, Cytisus scoparius (L.) Link (Fabaceae), in California, USA. The psyllid impacted plant growth in both field and greenhouse experiments, whereas drought stress affected plant growth in the greenhouse only, suggesting that other factors besides water availability may be more limiting for plants in the field. Effects on psyllid survival were consistent with the plant vigor hypothesis, which predicts that herbivores will perform better on vigorously growing plants; psyllid numbers were lower on drought‐stressed plants in the greenhouse and were correlated with plant growth in both the greenhouse and the field. In the greenhouse, the combined effects of the psyllid and drought stress were additive, indicating that the effects of the psyllid were consistent across unstressed and drought‐stressed plants. Although the psyllid is unlikely to control Scotch broom on its own, results suggest that it may work in conjunction with drought stress to suppress Scotch broom. [ABSTRACT FROM AUTHOR]

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The psyllids Cacopsylla melanoneura and Cacopsylla picta reproduce on apple (Malus × domestica) and transmit the bacterium ‘Candidatus Phytoplasma mali’, the causative agent of apple proliferation. Adult psyllids were collected by the beating-tray method from lower and upper parts of the apple tree canopy in the morning and in the afternoon. There was a trend of catching more emigrant adults of C.melanoneura in the morning and in the lower part of the canopy. For C.melanoneura remigrants, no differences were observed. The findings regarding the distribution of adults were reflected by the number of nymphs collected by wash-down sampling. The density of C.picta was too low for a statistical analysis. The vector monitoring and how it is commonly performed, is suitable for estimating densities of C.melanoneura. Nevertheless, above a certain temperature threshold, prediction of C.melanoneura density might be skewed. No evidence was found that other relatively abundant psyllid species in the orchard, viz. Baeopelma colorata, Cacopsylla breviantennata, Cacopsylla brunneipennis, Cacopsylla pruni and Trioza urticae, were involved in ‘Candidatus Phytoplasma mali’ transmission. The results of our study contribute to an advanced understanding of insect vector behavior and thus have a practical impact for an improved field monitoring.

The superfamily Psylloidea includes numerous species which play a key role in Australian ecology and biodiversity, as well as pests and biological control agents, and sometimes threatened species of conservation concern. Different psyllid sampling and collection techniques are usually performed depending on the nature and aim of the study: from the beating and sweeping of psyllid host plants for conservation and biodiversity assessment, to suction and sticky traps in agriculture. Due to a general lack of information on its efficacy for psyllids, however, light trapping has not usually been employed. Here we present the results obtained trapping psyllids using different light sources and we discuss the strengths and weaknesses of this technique to assess psyllid biodiversity. In particular, we highlight the strength of using this methodology paired with DNA barcoding, to cast some light on psyllid biodiversity. The results obtained here suggest that the psyllid fauna of Australia is heavily understudied and the number of undescribed species might be many times higher than previously expected. Additionally, we report, for the first time, the species Trioza adventicia Tuthill 1952, and Cryptoneossa triangula Taylor 1990 in the state of Queensland.

Studies of prey suitability are needed to develop efficient mass rearing programs for generalist predators and to understand their potential contribution to integrated pest management. A laboratory study was conducted to evaluate the development and reproductive success of two predatory coccinellids, Oenopia conglobata (L.) and Cheilomenes sexmaculata (Fabricius), reared on diets of the common pistachio psyllid, Agonoscena pistaciae Burckhardt & Lauterer, the cotton aphid, Aphis gossypii (Glover) or a reference diet of Ephestia kuehniella Zeller eggs. Development and reproductive performance of the two coccinellids varied with diet, but egg fertility and immature survival did not. The developmental period (egg-adult) was shortest for both species on A. gossypii. This prey also yielded the shortest preoviposition period and greatest fecundity for C. sexmaculata. The psyllid diet was superior for reproduction in O. conglobata. For both predators, eggs of E. kuehniella were a better diet for development than for reproduction. Life table data indicated that the arboreal O. conglobata was better adapted to A. pistaciae on pistachio trees and might be a more effective biocontrol agent for this pest, despite the fact that C. sexmaculata had a higher intrinsic rate of increase on all diets.

Fifteen species of Psyllaephagus from China are studied. Three species, P.clavus Zou & Zhang, sp. nov. , P.obliquus Zou & Zhang, sp. nov. , and P.tangae Zou & Zhang, sp. nov. , are described as new to science. A diagnosis or a description/redescription, figures of the characters, as well as the known distribution and hosts of each species are provided. A dichotomous key is also given to facilitate the identification of species., Competing Interests: The authors have declared that no competing interests exist., (Boyu Zou, Hongying Hu, Lanwei Zhang, Yanzhou Zhang.)

Fluorescence in situ hybridization (FISH) is a technique used to determine the chromosomal position of DNA and RNA probes. The present study contributes to knowledge on jumping plant-lice genomes by using FISH with 18S rDNA and telomeric (TTAGG)n probes on meiotic chromosomes of Psylla alni (2n = 24 + X), Cacopsylla mali (2n = 22 + neo-XY and 20 + neo-X1X2Y), C. sorbi (2n = 20 + neo-XY), Baeopelma foersteri (2n = 14 + X), and Rhinocola aceris (2n = 10 + X). This is the fi rst study that has used FISH on the hemipteran superfamily Psylloidea. We found that the chromosomes of all studied species contain the insecttype telomere motif, (TTAGG)n. In C. mali and C. sorbi, the neo-sex chromosomes originating from autosome-sex chromosome fusions showed no interstitially located clusters of TTAGG repeats, suggesting their loss or inactivation. Similarly, no interstitial (TTAGG)n clusters were detected in an extremely large autosome pair of B. foersteri that most likely originated from a fusion of at least fi ve ancestral chromosome pairs. Clusters of 18S rDNA were detected on the fused and second largest autosome pairs of B. foersteri and on one of the large autosome pairs of the remaining species. In C. mali and B. foersteri, the rDNA clusters were shown to coincide with the NORs as detected by the AgNOR method. Finally, we speculate, based on the obtained FISH markers, on the mechanisms of karyotype evolution of psylloid species differing in chromosome numbers and sex chromosome systems. [ABSTRACT FROM AUTHOR]

Authors made regular insect collections between 2010 and 2017, especially on ornamental trees and shrubs, on streets, parks, in city greenery, forests, botanical gardens and private gardens, in various localities of Hungary. Trioza soniae Rapisarda, 1994 and Trioza scottii Löw, 1880 are reported for the first time in Hungary. New host, locality and habitat data are given. [ABSTRACT FROM AUTHOR]

Baccharis spicata is a plant native to the south of South America And is infected by psyllids of the Baccharopelma genus, which induce a fold gall in its leaves. This infection induces a series of anatomical and phytochemical variations compared to the healthy leaf: the content of total phenolic compounds and total hidroxycinnamic derivatives is lower, though the chlorogenic acid measured by HPLC remains the same and the 4,5 dichlorogenic acid content is near the half of the one observed in the one in the healthy leaf. Regarding to its anatomy, the gall has an homogeneous mesophyll and flavonoids in its outer epidermis compared to an isobilateral mesophyll and epidermal flavonoidic idioblasts observed in the leaf. The increase in the expression of waxes suggests it is a protective function against the desiccation by preventing water evaporation in the structure. The results here exposed suggest that the psyllid manipulates plant tissues, inducing hyperplasia and hypertrophy in the tissues, differentiating them from healthy structures and inducing changes in the biosynthesis of secondary polyphenolic metabolites that act like intermediary between the gall and the environment. [ABSTRACT FROM AUTHOR]

Oenopia conglobata is one of the most common ladybird species in urban green areas of the Mediterranean region. We have obtained data about its prey acceptability and prey preferences. In a laboratory experiment, we investigated the acceptability of seven aphid and one psyllid species as prey for this coccinellid: the aphids Chaitophorus populeti, Aphis gossypii, Aphis craccivora Monelliopsis caryae, Eucallipterus tiliae, Aphis nerii (on white poplar, pomegranate, false acacia, black walnut, lime, and oleander, respectively), and the psyllid Acizzia jamatonica on Persian silk tree. These species are abundant in urban green areas in the Mediterranean region. In addition, we tested the acceptability of Rhopalosiphum padi on barley, an aphid species easily reared in the laboratory. We also tested preferences of the predator in cafeteria experiments with three aphid species and one aphid and the psyllid. Adults and larvae of the coccinellid accepted all of the preys offered, except A. nerii, with a clear preference for M. caryae. The predator also showed preference for M. caryae when it was offered in a cafeteria experiment with other aphid species or with the psyllid. The aphid R. padi obtained a good acceptability and could be used for rearing O. conglobata in the laboratory. [ABSTRACT FROM AUTHOR]