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Background Lactobacillus is a genus of Gram-positive non-spore-forming rods usually found in the microbiota of the oral cavity, gastrointestinal tract, and female genitourinary tract. Also, they are commonly used in the food industry as supplements and probiotics. Lactobacilli are normally considered non-pathogenic to the human body, however, under certain circumstances such as immunosuppression, they can cause severe infections, with only a few cases of bacteremia, infective endocarditis, pneumonia, meningitis, and intra-abdominal infections reported. Among these presentations, a pyogenic liver abscess is rather rare. Case presentation We describe the case of a 59-year-old man with a history of diabetes mellitus and multiple abdominal surgeries with the latest being in 2014 presenting with bacteremia and multiple large pyogenic liver abscesses due to Lactobacillus gasseri, which did not appear to be related to the use of probiotics or immunosuppression. Conclusions Given the high prevalence of diabetes mellitus and the increased use of probiotics, it is expected that in the future we will see an increase in infections caused by Lactobacilli. Medical management with antibiotics and percutaneous drainage were successful strategies for the treatment of this unusual case of pyogenic liver abscesses and bacteremia caused by Lactobacillus gasseri.

Fungus farming ambrosia beetles carry their nutritional mutualistic fungi in specialized structures called mycetangia. Fungal propagules are also dispersed phoretically on the beetle’s exoskeleton. We determined the phoretic presence and abundance of Raffaelea lauricola, the causal agent of the laurel wilt disease in avocado, on five ambrosia beetle species: Xyleborus bispinatus, Xyleborus volvulus, Xyleborus affinis, Xyleborinus saxesenii and Xylosandrus crassiusculus. Beetles were captured while in flight, excavated from logs, and from logs placed in emergence chambers. Beetles collected by the three methods were assayed for the presence of internal (gut and mycetangium) and external (attached to the exoskeleton) colony forming units (CFUs) of R. lauricola. The pathogen was recovered from the exoskeleton of all beetle species. The collection method significantly influenced the frequency of pathogen recovery, and the abundance of both internal and phoretic R. lauricola was species-specific. Internal CFUs recovery was greater than phoretic recovery. Besides R. lauricola, other cycloheximide tolerant fungi, including mutualistic and entomopathogenic fungi, were isolated from the beetle’s exoskeleton. However, phoretic CFUs of R. lauricola were more prevalent and abundant than any other mutualistic phoretic fungi across the beetle species. Our results suggest that phoresy is a common mechanism of transportation of wood-inhabiting fungi and that phoretic transmission of R. lauricola may potentially contribute to the infection in avocado.

Studies were conducted from 2015 to 2018 to evaluate spotted lanternfly (SLF) distribution and developmental suitability of different plant species in the U.S. Tree bands on 283 trees spanning 33 species captured 21,006 SLF in 2 yr. More SLF per tree were trapped on tree-of-heaven Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae) than on other species, on average, and most adults were captured on tree-of-heaven. Frequency of detection of adult SLF was higher on tree-of-heaven than on other species but was actually equal or lower on tree-of-heaven than on all other species combined for younger SLF stages in 2015. An enclosed choice test between tree-of-heaven and black walnut Juglans nigra L. (Fagales: Juglandaceae) revealed nymphs showed little consistent preference, whereas adults consistently and significantly preferred tree-of-heaven. No-choice field sleeve studies evaluated SLF survivorship on 26 host plant species in 17 families. Ten plant species supported SLF for an average of ≥45 d, with the rest unable to support SLF for >30 d. Eight species were able to support development from first instar to adult: black walnut, chinaberry Melia azedarach L. (Sapindales: Meliaceae), oriental bittersweet Celastrus orbiculatus Thunb. (Celastrales: Celastraceae), tree-of-heaven, hops Humulus lupulus L. (Rosales: Cannabaceae), sawtooth oak Quercus acutissima Carruthers (Fagales: Fagaceae), butternut Juglans cinerea L, and tulip tree Liriodendron tulipifiera L. (Magnoliales: Magnoliaceae). The ability of SLF to develop to adult on hosts other than tree-of-heaven may impact pest management decisions.

Host plant volatiles play a key role in mediating plant–herbivore interactions. How an array of host plant volatiles guides host preference and attraction in the invasive polyphagous Lycorma delicatula (White), the spotted lanternfly (SLF), is largely unknown. A pernicious phloem feeder, SLF feeds on over 70 species of plants, some with high economic impact. To aid the development of detection and monitoring tools for SLF, we used a two-choice olfactometer to compare 14 host plant species for attraction, first to a blank control, and then to their preferred host Ailanthus altissima (Mill.) Swingle (Sapindales: Simaroubaceae), tree-of-heaven. SLF were significantly attracted to seven host plants compared to a blank control, but no host plant was more attractive than tree-of-heaven. We then used electroantennographic detection (EAD) to screen select host plants for EAD active compounds, hypothesizing that EAD-active plant volatiles act as kairomones and mediate SLF attraction to host plants. Out of 43 unique antennal responses, 18 compounds were identified and tested individually for attraction in a two-choice olfactometer against a blank control and then against methyl salicylate, the current best attractant. Eleven compounds were significantly attractive, and one, sulcatone, was more attractive than methyl salicylate. Blends of kairomones were then tested for attraction, revealing five blends that were significantly more attractive than methyl salicylate, and could be developed into lures for field testing. The presence of these kairomones in volatile profiles of 17 plant species is described. These findings support the hypothesis that the identified volatiles act as kairomones and function in attraction to host plants.

Population outbreaks and failures in controlling Tetranychus urticae Koch (Acari: Tetranychidae) were reported on ornamental plants in Miami-Dade County, Florida. We compared the susceptibility of two T. urticae field populations collected from commercial nurseries with a laboratory population to one new generation (cyflumetofen) and two conventional (abamectin and pyridaben) acaricides. The field populations were collected from hibiscus (Hibiscus rosa-sinensis, Malvaceae) and croton (Codiaeum variegatum, Euphorbiaceae). Resistance ratios based on LC50 values of the field and laboratory populations revealed high resistance levels to the two conventional acaricides (9.64 and 19.28-fold abamectin, 12.34 and 34.08-fold pyridaben), and low levels (1.88 and 2.39-fold) of cyflumetofen resistance in the hibiscus and the croton populations, respectively. Rotation of acaricides with different modes of action and biological control should be implemented to mitigate T. urticae resistance problems in ornamentals in south Florida.

A profile of the hibiscus bud weevil intended for the use of interested laypersons with some knowledge of biology as well as academic audiences. The hibiscus bud weevil, a pest of China rose hibiscus, originates from northeastern Mexico and southern Texas and can cause large economic losses to hibiscus growers. This fact sheet provides nursery owners, homeowners, and other interested people with information on this serious pest.

The spotted lanternfly, Lycorma delicatula (White), is an invasive phloem feeder recently introduced into North America that attacks a broad range of woody plants. When feeding in large numbers, they can seriously damage or kill a tree. Their preferred host is the invasive tree-of-heaven, Ailanthus altissima Swingle (Sapindales: Simaroubaceae), but they are serious pests of grape, Vitis vinifera L. (Vitales: Vitaceae) and a number of other commercially important host plants. Volatile collections were conducted on tree-of-heaven and grape, and the most abundant compounds from these plants present in samples and indicated in the literature were tested for attraction in the laboratory and field. Three compounds, methyl salicylate, (Z)-3-hexenol, and (E,E)-α-farnesene, were found to be highly attractive in laboratory behavioral bioassays. Methyl salicylate was attractive to all stages of L. delicatula, whereas the youngest nymphs were not as attracted to (Z)-3-hexenol or (E,E)-α-farnesene in laboratory bioassays. When comparing individual compounds, methyl salicylate attracted the most L. delicatula. Methyl salicylate lures in the field produced a two- to four-fold increase in captures compared with unbaited controls, and field testing also revealed a significant positive dose response. Of the several types of sticky bands tested, Web-Cote Industries sticky bands were found to be most efficient at trapping L. delicatula adults and nymphs.

We provide an overview of both traditional and innovative control tools for management of three Xylosandrus ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), invasive species with a history of damage in forests, nurseries, orchards and urban areas. Xylosandrus compactus, X. crassiusculus and X. germanus are native to Asia, and currently established in several countries around the globe. Adult females bore galleries into the plant xylem inoculating mutualistic ambrosia fungi that serve as food source for the developing progeny. Tunneling activity results in chewed wood extrusion from entry holes, sap outflow, foliage wilting followed by canopy dieback, and branch and trunk necrosis. Maintaining plant health by reducing physiological stress is the first recommendation for long-term control. Baited traps, ethanol-treated bolts, trap logs and trap trees of selected species can be used to monitor Xylosandrus species. Conventional pest control methods are mostly ineffective against Xylosandrus beetles because of the pests’ broad host range and rapid spread. Due to challenges with conventional control, more innovative control approaches are being tested, such as the optimization of the push–pull strategy based on specific attractant and repellent combinations, or the use of insecticide-treated netting. Biological control based on the release of entomopathogenic and mycoparasitic fungi, as well as the use of antagonistic bacteria, has yielded promising results. However, these technologies still require validation in real field conditions. Overall, we suggest that management efforts should primarily focus on reducing plant stress and potentially be combined with a multi-faceted approach for controlling Xylosandrus damage. This research was supported by the University of Catania (Project Emergent Pests and Pathogens and Relative Sustainable Strategies - 5A722192113; PhD fellowship to AG). P.H.W.B. was supported by the German Research Foundation (DFG Emmy Noether Grant BI 1956/1–1). Funding to MGW: USDA-NIFA, ARS and APHIS; ISDA Hatch; Hawaii Dept. of Agriculture. JH and YL were funded by the USDA APHIS and USDA Forest Service. HK was partially supported by Japan Society for the Promotion of Science (Grant-in-Aid for Scientific Research, KAKENHI, Nos. 18KK0180, 19H02994 and 20H03026). KH was partially supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes, Brazil; Finance code 001). Open access funding provided by Università degli Studi di Catania within the CRUI-CARE Agreement.

Laurel wilt (LW) is a vascular disease caused by a fungal pathogen transmitted to avocado trees by several ambrosia beetle species and through root grafts among adjacent avocado trees. A critical part of preventing and controlling plant diseases is determining the causal agent so that the appropriate management practices can be implemented to eradicate or contain the outbreak. Proper sampling is a critical step in disease diagnosis and in the determination of the causal agent of disease. This new 3-page publication of the UF/IFAS Horticultural Sciences Department was written by Jonathan Crane, Romina Gazis, Jeff Wasielewski, Daniel Carrillo, Bruce Schaffer, Fredy Ballen, and Edward Evans.https://edis.ifas.ufl.edu/hs1394

Made available in DSpace on 2020-12-12T02:10:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-10-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) U.S. Department of Agriculture Citrus leprosis is a serious viral disease of citrus transmitted by Brevipalpus mites. The disease is present in South America, Central America, and Mexico, but not in the United States. One of its primary vectors, however, is present in Florida and other southern states. Non-viruliferous Brevipalpus yothersi (Acari: Tenuipalpidae) are present in Florida and could facilitate the spread of the disease if citrus leprosis viruses (CiLVs) are introduced into the state. In preparation for the possible incursion of CiLVs, we evaluated the biological control potential of four predatory mite species (Neoseiulus longispinosus, N. californicus, Amblyseius largoensis; Acari: Phytoseiidae) and Hemicheyletia bakeri (Acari: Cheyletidae) that are naturally associated with Brevipalpus spp. in citrus. In laboratory no-choice assays, the phytoseiid mites preyed mostly upon immature stages of B. yothersi, while H. bakeri preyed mainly on adults. In dual choice assays, all predators preferred Tetranychus urticae (Acari: Tetranychidae) over B. yothersi, but A. largoensis consumed more B. yothersi than the other three predators. A greenhouse experiment was performed to evaluate the potential of A. largoensis and H. bakeri to suppress B. yothersi populations on citrus trees. Four predator release treatments consisting of single or combined releases of A. largoensis and H. bakeri at a 1:10 (predator: B. yothersi) ratio were tested. Releases of A. largoensis alone or in combination with H. bakeri effectively suppressed B. yothersi and reduced damage to citrus plants. Release of H. bakeri alone, however, had no suppressive effect on B. yothersi populations. Overall, our results show that A. largoensis could be an efficient biological control agent of B. yothersi and could play an important role in citrus IPM programs tailored to manage citrus leprosis. Tropical Research & Education Center University of Florida, 18905 SW 280th Street Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (FCAV/UNESP) Departamento de Fitossanidade Çukurova University Agricultural Faculty Department of Plant Protection Acarology Lab United States Department of Agriculture Animal and Plant Health Inspection Service Plant Protection and Quarantine Science and Technology Faculdade de Ciências Agrárias e Veterinárias Universidade Estadual Paulista (FCAV/UNESP) Departamento de Fitossanidade

Interest in preventive or therapeutic strategies targeting gut microbiota is increasing. Such strategies may involve the direct replenishment of the gut microbiota with single strains or strain mixtures, or the manipulation of strain abundance through dietary intervention, including lactic acid bacteria. A few candidate species associated with health benefits have been identified, including Faecalibacterium prausnitzii. Given its growth requirements, modulation of this bacterium has not been extensively studied. In this investigation, we explored the capacity of cell-free supernatants of different Lactobacillus, Streptococcus, Lactococcus, and Bifidobacterium strains to stimulate the growth of F. prausnitzii A2-165. Modulation by four strains with the greatest capacity to stimulate growth or delay lysis, Lactococcus lactis subsp. lactis CNCM I-1631, Lactococcus lactis subsp. cremoris CNCM I-3558, Lactobacillus paracasei CNCM I-3689, and Streptococcus thermophilus CNCM I-3862, was further characterized by transcriptomics. The response of F. prausnitzii to cell-free supernatants from these four strains revealed several shared characteristics, in particular, upregulation of carbohydrate metabolism and cell wall-related genes and downregulation of replication and mobilome genes. Overall, this study suggests differential responses of F. prausnitzii to metabolites produced by different strains, providing protection against cell death, with an increase in peptidoglycan levels for cell wall formation, and reduced cell mobilome activity.

Invasive ambrosia beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini) have recently become established in several regions of the US where they vector fungal pathogens responsible for vascular wilt diseases in avocado (Persea americana), woody ornamentals, and native forest trees. These include the redbay ambrosia beetle (Xyleborus glabratus) that vectors the fungus responsible for laurel wilt, and a group of cryptic species morphologically similar to tea shot-hole borer (Euwallacea fornicatus) that vectors the pathogen of Fusarium dieback. Ecologically, these wood-boring beetles function as primary colonizers, capable of attacking healthy unstressed trees. Thus, they are attracted to the volatile terpenoids emitted from host wood (i.e., kairomones used by females for host location). Since essential oils consist of concentrated plant terpenoids, they have provided an ideal substrate for development of lures for these pests. This chapter (a) summarizes the succession of essential oil lures used for redbay ambrosia beetle over the last decade, (b) outlines development of the current lure which is highly enriched in (−)-α-copaene, (c) presents chemical analysis of the α-copaene lure, and (d) describes its recent applications for detection of Euwallacea pests in Florida avocado groves.

Until recently, the Old World bollworm (OWB) Helicoverpa armigera (H&uuml, bner) and the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) were geographically isolated. Both species are major pests of agricultural commodities that are known to develop insecticide resistance, and they now coexist in areas where H. armigera invaded the Americas. This is the first study to compare the susceptibility of the two species to conventional insecticides. The susceptibility of third instar H. armigera and H. zea larvae to indoxacarb, methomyl, spinetoram, and spinosad was determined using a diet-overlay bioassay in a quarantine laboratory in Puerto Rico. Mortality was assessed at 48 h after exposure for up to eight concentrations per insecticide. Spinetoram exhibited the highest acute toxicity against H. armigera, with a median lethal concentration (LC50) of 0.11 &micro, g a.i./cm2, followed by indoxacarb and spinosad (0.17 &micro, g a.i./cm2 for both) and methomyl (0.32 &micro, g a.i./cm2). Spinetoram was also the most toxic to H. zea (LC50 of 0.08 &micro, g a.i./cm2), followed by spinosad (0.17 &micro, g a.i./cm2) and methomyl (0.18 &micro, g a.i./cm2). Indoxacarb was the least toxic to H. zea, with an LC50 of 0.21 &micro, g a.i./cm2. These findings could serve as a comparative reference for monitoring the susceptibility of H. armigera and H. zea to indoxacarb, methomyl, spinetoram, and spinosad in Puerto Rico, and may facilitate the detection of field-selected resistance for these two species and their potential hybrids in areas recently invaded by H. armigera.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae) is a vector of the bacterium that causes huanglongbing (HLB), a disease heavily impacting citrus production in many areas worldwide. Neither the psyllid nor the disease have been found in the Mediterranean yet, where citrange Carrizo (Citrus sinensis Osb. x Poncirus trifoliata L. Raf.) is extensively used as citrus rootstock. This study evaluated the suitability of this rootstock as a host for D. citri in both laboratory and greenhouse conditions. The suitability of sour orange (Citrus aurantium L.) (highly susceptible) and trifoliate orange (Poncirus trifoliata L. Raf.) (highly resistant) was also assessed. Host suitability was determined based on host plant selection, oviposition, and survival of D. citri. Under laboratory conditions the psyllid preferentially chose and oviposited on citrange Carrizo and sour orange rather than on P. trifoliata. Greenhouse experiments demonstrated that oviposition on P. trifoliata was nil and provided evidence that citrange Carrizo is an extremely favorable host for D. citri development and reproduction. This information is important for the Mediterranean region, where HLB could prove devastating for the citrus industry because of the widespread use of citrange Carrizo as rootstock.

The lethal laurel wilt epidemic affecting avocado trees in Florida is caused by a fungal pathogen-ambrosia beetle complex (LW-AB). The death of over 120,000 commercial avocado trees in Florida may be attributed to LW-AB. Recommendations for control and mitigation of this epidemic are needed to guide commercial producers in their decision-making process. This new 8-page publication of the UF/IFAS Horticultural Sciences Department outlines the LW-AB epidemic, provides information on the pathogen and ambrosia beetle vectors, provides a brief outline of current research findings, and offers recommendations for the control and mitigation of LW-AB. Written by Jonathan H. Crane, Daniel Carrillo, Edward A. Evans, Romina Gazis, Bruce Schaffer, Fredy Ballen, and Jeff Wasielewski. Correction as of 3/30/2020: Under "Prophylactic Fungicide Injections," this document previously said that when using Tilt, growers needed to have in their possession a Section 18 special local needs label (SLN). This has been corrected to read that they need a Section 18 Emergency Exemption label.

Avocado trees are a popular choice for homeowners in Florida, with over 600,000 growing in Florida home landscapes. However, avocado trees as well as others in the Lauraceae family are susceptible to laurel wilt disease, which can kill a tree in as few as three weeks. This new publication of the UF/IFAS Horticultural Sciences Department provides home owners recommendations for identifying and mitigating laurel wilt disease in the home landscape. Written by Jonathan H. Crane, Jeff Wasielewski, Daniel Carrillo, Romina Gazis, Bruce Schaffer, Fredy Ballen, and Edwards Evans.https://edis.ifas.ufl.edu/hs1358

Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) bore into tree xylem to complete their life cycle, feeding on symbiotic fungi. Ambrosia beetles are a threat to avocado where they have been found to vector a symbiotic fungus, Raffaelea lauricola, the causal agent of the laurel wilt disease. We assessed the repellency of methyl salicylate and verbenone to two putative laurel wilt vectors in avocado, Xyleborus volvulus (Fabricius) and Xyleborus bispinatus (Eichhoff), under laboratory conditions. Then, we tested the same two chemicals released from SPLAT flowable matrix with and without low-dose ethanol dispensers for manipulation of ambrosia beetle populations occurring in commercial avocado. The potential active space of repellents was assessed by quantifying beetle catch on traps placed ‘close’ (~5–10 cm) and ‘far’ (~1–1.5 m) away from repellent dispensers. Ambrosia beetles collected on traps associated with all in-field treatments were identified to species to assess beetle diversity and community variation. Xyleborus volvulus was not repelled by methyl salicylate (MeSA) or verbenone in laboratory assays, while X. bispinatus was repelled by MeSA but not verbenone. Ambrosia beetle trap catches were reduced in the field more when plots were treated with verbenone dispensers (SPLAT) co-deployed with low-dose ethanol dispensers than when treated with verbenone alone. Beetle diversity was highest on traps deployed with low-dose ethanol lures. The repellent treatments and ethanol lures significantly altered the species composition of beetles captured in experiment plots. Our results indicate that verbenone co-deployed with ethanol lures holds potential for manipulating ambrosia beetle vectors via push-pull management in avocado. This tactic could discourage immigration and/or population establishment of ambrosia beetles in commercial avocado and function as an additional tool for management programs of laurel wilt.

The bacterial and fungal community involved in ambrosia beetle fungiculture remains poorly studied compared to the famous fungus-farming ants and termites. Here we studied microbial community dynamics of laboratory nests, adults, and brood during the life cycle of the sugarcane shot hole borer, Xyleborus affinis. We identified a total of 40 fungal and 428 bacterial operational taxonomic units (OTUs), from which only five fungi (a Raffaelea fungus and four ascomycete yeasts) and four bacterial genera (Stenotrophomonas, Enterobacter, Burkholderia, and Ochrobactrum) can be considered the core community playing the most relevant symbiotic role. Both the fungal and bacterial populations varied significantly during the beetle’s life cycle. While the ascomycete yeasts were the main colonizers of the gallery early on, the Raffaelea and other filamentous fungi appeared after day 10, at the time when larval hatching happened. Regarding bacteria, Stenotrophomonas and Enterobacter dominated overall but decreased in foundresses and brood with age. Finally, inferred analyses of the putative metabolic capabilities of the bacterial microbiome revealed that they are involved in (i) degradation of fungal and plant polymers, (ii) fixation of atmospheric nitrogen, and (iii) essential amino acid, cofactor, and vitamin provisioning. Overall, our results suggest that yeasts and bacteria are more strongly involved in supporting the beetle-fungus farming symbiosis than previously thought., Research reported in this publication was supported by CONACyT-FORDECYT number 292399, Spanish Ministry of Economy and Competitiveness under award numbers SAF2015-65878-R and PGC2018-099344-B-I00, cofinanced by the European Regional Development Fund (ERDF), and from Generalitat Valenciana (project Prometeo/2018/A133). P.H.W.B. was supported by the German Research Foundation (DFG Emmy Noether grant BI 1956/1-1).

Survival of ambrosia beetles relies on obligate nutritional relationships with fungal symbionts that are cultivated in tunnels excavated in the sapwood of their host trees. The dynamics of fungal associates, along with the developmental biology, and gallery construction of the ambrosia beetle Xyleborus bispinatus were elaborated. One generation of this ambrosia beetle was reared in an artificial medium containing avocado sawdust. The developmental time from egg to adult ranged from 22 to 24 d. The mean total gallery length (14.4 cm and 13 tunnels) positively correlated with the number of adults. The most prevalent fungal associates were Raffaelea arxii in the foundress mycangia and new galleries, and Raffaelea subfusca in the mycangia of the F1 adults and the final stages of the galleries. Raffaelea sp. PL1001, Raffaelea subalba and seven yeast species were also recovered. These results indicate flexibility in the association between X. bispinatus and its symbiont species, and that this beetle may use more than one Raffaelea species as a food source. These results are important, as X. bispinatus has been associated with the transmission of Raffaelea lauricola, the causal agent of laurel wilt, a lethal disease affecting avocado trees.

Ambrosia beetles have emerged as significant pests of avocado ((Persea americana Mill. [Laurales: Lauraceae])) due to their association with pathogenic fungal symbionts, most notably Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), the causal agent of the laurel wilt (LW) disease. We evaluated the interaction of ambrosia beetles with host avocado trees by documenting their flight height and daily flight periodicity in Florida orchards with LW. Flight height was assessed passively in three avocado orchards by using ladder-like arrays of unbaited sticky traps arranged at three levels (low: 0-2 m; middle: 2-4 m; high: 4-6 m). In total, 1,306 individuals of 12 Scolytinae species were intercepted, but six accounted for ~95% of the captures: Xyleborus volvulus (Fabricius) (Coleoptera: Curculionidae), Xyleborinus saxesenii Ratzeburg (Coleoptera: Curculionidae), Euplatypus parallelus (Fabricius) (Coleoptera: Curculionidae), Xyleborus bispinatus Eichhoff (Coleoptera: Curculionidae), Xyleborus affinis Eichhoff (Coleoptera: Curculionidae), and Hypothenemus sp. (Coleoptera: Curculionidae). The primary vector of R. lauricola, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae), was not detected. Females of X. volvulus showed a preference for flight at low levels and X. bispinatus for the low and middle levels; however, captures of all other species were comparable at all heights. At a fourth orchard, a baiting method was used to document flight periodicity. Females of X. saxesenii and Hypothenemus sp. were observed in flight 2-2.5 h prior to sunset; X. bispinatus, X. volvulus, and X. affinis initiated flight at ~1 h before sunset and Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae) at 30 min prior to sunset. Results suggest that ambrosia beetles in South Florida fly near sunset (when light intensity and wind speed decrease) at much greater heights than previously assumed and have species-specific patterns in host-seeking flight.

Ambrosia beetles in the cryptic species complex Euwallacea nr. fornicatus vector a fungal pathogen responsible for Fusarium dieback, a disease that impacts avocado (Persea americana), woody ornamentals, and numerous native trees in the USA (California, Florida), Israel, and other countries. Currently, these pests are detected with quercivorol lures (containing p-menth-2-en-1-ol isomers), but recent research identified an essential oil enriched in (-)-α-copaene as a new attractant. In this study, lure longevity and efficacy were assessed in three 12-week field tests conducted in Florida by deploying traps baited with quercivorol, α-copaene, and a combination of the two. A fourth test compared different formulations of quercivorol. Concurrent with field experiments, gas chromatographic analyses were conducted to quantify initial lure contents as well as volatile emissions from lures field-aged for 12 weeks. In all tests, the lure combination captured significantly more E. nr. fornicatus than the individual lures; and in two trials, synergistic attraction was observed. Field life of the combination lure was 12 weeks; longevity of single lures varied from 9 to 12 weeks. Twelve terpenoids were detected from the α-copaene-enriched oil, suggesting there may be additional attractants. Analysis of the quercivorol lure showed it contained 88% trans- and 9% cis-p-menth-2-en-1-ol. Results indicate that the combination of quercivorol and α-copaene provides a long-lasting, effective lure for early detection of E. nr. fornicatus in Florida. Further research is needed to determine which isomer of p-menth-2-en-1-ol is attractive to Florida E. nr. fornicatus, and if other members of the species complex are attracted to (-)-α-copaene.

Caribbean fruit fly, also known as Caribfly or Anastrepha suspensa, is a major tephritid pest of guavas. A virulent entomopathogenic nematode (EPN) species was investigated to suppress the fruit-to-soil stages of Caribflies, which are also attacked by the koinobiont parasitoid Diachasmimorpha longicaudata in south Florida. The main objective was to develop a feasible and cost-effective EPN-application method for integrated pest management (IPM) of Caribfly to improve guava production. Naturally infested guavas were treated with increasing Heterorhabditis bacteriophora infective juvenile (IJ) concentration or rate (0, 25, 50, …, 1,600 IJs cm−2) in field trials to measure the optimum IJ rate and then examine sensitivity of producing guavas to inclusion of Heterorhabditis bacteriophora in Caribfly IPM plans. Relative survival of Caribfly in treatments significantly decreased with increasing IJ rate from 0 to 100 IJs cm−2. Similarly, probability of observing large numbers of parasitoid wasps (Diachasmimorpha longicaudata) in EPN treatments significantly declined with increasing IJ rate (0–100 IJs cm−2), even though the non-target effects of Heterorhabditis bacteriophora on relative survival of Diachasmimorpha longicaudata could not be determined because of few emerging parasitoid wasps. Optimum suppression (⩾ 60%) of Caribfly was consistently achieved at 100 IJs cm−2 or 17,500 IJs fruit−1. Profitability analysis showed that Heterorhabditis bacteriophora can be included in Caribfly IPM tactics to produce guavas. Costs of EPNs in Caribfly IPM are minimized if Heterorhabditis bacteriophora is strategically applied by spot treatment of fruit. Repayment of costs of EPN-augmentation by spot treatments appears achievable by recovering 5.71% of the annual yield losses (⩾1,963 kg ha−1 ≈ US$ 8,650 ha−1), which are largely due to Caribfly infestation. Hectare-wide EPN-augmentation (or broadcasting) method requires more fruit recovery than the total annual yield losses to repay its high costs. Profitability of guava production in south Florida will not be very sensitive to marginal costs of the spot treatment method, when compared to the field-wide broadcasting of Heterorhabditis bacteriophora.

Intraguild interactions can be crucial for the success of biological control programs involving multiple natural enemies. The two-spotted spider mite (TSSM), Tetranychus urticae (Acari: Tetranychidae) is a major pest of papaya, Carica papaya, in south Florida, where a newly naturalized predator, Neoseiulus longispinosus (Acari: Phytoseiidae), has become the most abundant predator associated with this pest. Amblyseius largoensis and Neoseiulus californicus are other, less common, phytoseiid predators on papaya and the exotic predator, Amblyseius swirskii, is often released to control other mite and insect pests of this crop. We investigated intra- and interspecific interactions among these four predatory mite species and their effects on biological control of TSSM. Cannibalism and intraguild predation were evaluated in the laboratory for all four predator species in the absence and presence of TSSM. Neoseiulus longispinosus was the most cannibalistic species in the absence of spider mites, and A. largoensis when spider mites were available. Whereas A. swirskii was the most aggressive intraguild predator, N. longispinosus was the least aggressive and most often the intraguild prey of other predators. Single and combined releases of A. swirskii and N. longispinosus were evaluated to assess the effects of cannibalism and intraguild predation on biocontrol of TSSM on potted papaya plants. Single releases of N. longispinosus significantly suppressed TSSM populations but releases of A. swirskii alone or in combination with N. longispinosus resulted in gradual increases in TSSM populations. Our results showed that N. longispinosus has potential to control TSSM on papaya, but the level of control can be negatively affected by 1) high levels of cannibalism at low prey densities, 2) intraguild predation by other mite predators and 3) releases of aggressive intraguild predators like A. swirskii.

In the present study, we report the in-vitro antifungal activity of ZnO nanoparticles (NPs) against three species of the ambrosia beetle mutualistic fungi, Raffaelea arxii, Raffaelea subfusca, Raffaelea lauricola. The latter is the causal agent of laurel wilt, a deadly vascular disease of avocado. The effect of coating and size of two kinds of ZnO-NPs on the antifungal activity against those mutualistic is presented. The NPs obtained by the hydrothermal method (hyd-ZnO) were uncoated plate-like NPs with sizes between 200 and 600 nm, while the NPs obtained by sol–gel (sg-ZnO) were PEG-coated semi-spherical NPs with ~60 nm in size. Although the inhibition percentage was higher than 80% for both kinds of NPs (at a concentration of 0.5 mg/ml), the highest antifungal capacity was exhibited by the hyd-ZnO-NPs. Here we show that despite the size of the NPs, which is a crucial parameter, the coating of ZnO-NPs is the most critical factor for the improvement of their antifungal properties.

Entomopathogenic nematode (EPN) species richness merits studies towards making rational decisions for effective management of Caribfly, Anastrepha suspensa (Loew) in southern Florida. Competition for Caribfly and efficacies of EPN biodiversity were examined under laboratory conditions. Similar EPN species treatments to Caribfly-infested fruits, periodically obtained from the ground in groves which were also infested by the parasitoid Diachasmimorpha longicaudata Ashmead (Braconidae), were studied in a series of field trials. Treatments with individual EPN species and their mixtures caused similar mortalities of Caribfly larvae, though the various EPN species competed for larvae in multiple-species treatments. Laboratory trials showed that mortalities of EPN-treated Caribfly pupae were mostly inversely related to EPN diversity. In the field, population densities of emerging adult Caribfly increased with increasing number of EPN species combined in treatments. Thus, single-EPN species treatments proved to be more effective for the management of fruit-to-soil stages of Caribfly. Relative to controls, the proportions of surviving adult Caribfly observed in EPN treatments with Heterorhabditis bacteriophora (exotic in Florida), Steinernema feltiae (exotic EPN) and Heterorhabditis indica (the endemic species) in field plots were 22.5 ± 6, 45 ± 13 and 47 ± 13%, respectively. Number of emerging D. longicaudata in each of EPN species treatments was similar to that observed in control, suggesting that none of the EPN species significantly affected the emergence of D. longicaudata, a parasitoid of Caribfly. Heterorhabditis bacteriophora will be more promising, with insignificant side effects on D. longicaudata in Caribfly-integrated pest management.

Like other ambrosia beetles, Xyleborus volvulus Fabricius (Coleoptera: Curculionidae) lives in a mutualistic symbiotic relationship with fungi that serve as food source. Until recently, X. volvulus was not considered a pest, and none of its symbionts were considered plant pathogens. However, recent reports of an association between X. volvulus and Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), the cause of the laurel wilt disease of avocado (Persea americana Mill. [Laurales: Lauraceae]), and its potential role as vector of the pathogen merit further investigation. The objective of this study was to evaluate three artificial media containing sawdust obtained from avocado or silkbay (Persea humilis Nash) for laboratory rearing of X. volvulus. The effect of R. lauricola in the media on the beetle's reproduction was also evaluated. Of the three media, the one with the lowest content of sawdust and intermediate water content provided the best conditions for rearing X. volvulus. Reproduction on this medium was not affected by the sawdust species or the presence of R. lauricola. On the other two media, there was a significant interaction between sawdust species and R. lauricola. The presence of R. lauricola generally had a negative effect on brood production. There was limited colonization of the mycangia of X. volvulus by R. lauricola on media inoculated with the pathogen. From galleries formed within the best medium, there was 50% recovery of R. lauricola, but recovery was much less from the other two media. Here, we report the best artificial substrate currently known for X. volvulus.

Ambrosia beetles subsist on fungal symbionts that they carry to, and cultivate in, their natal galleries. These symbionts are usually saprobes, but some are phytopathogens. Very few ambrosial symbioses have been studied closely, and little is known about roles that phytopathogenic symbionts play in the life cycles of these beetles. One of the latter symbionts, Raffaelea lauricola, causes laurel wilt of avocado, Persea americana, but its original ambrosia beetle partner, Xyleborus glabratus, plays an uncertain role in this pathosystem. We examined the response of a putative, alternative vector of R. lauricola, Xyleborus bispinatus, to artificial diets of R. lauricola and other ambrosia fungi. Newly eclosed, unfertilized females of X. bispinatus were reared in no-choice assays on one of five different symbionts or no symbiont. Xyleborus bispinatus developed successfully on R. lauricola, R. arxii, R. subalba and R. subfusca, all of which had been previously recovered from field-collected females of X. bispinatus. However, no development was observed in the absence of a symbiont or on another symbiont, Ambrosiella roeperi, recovered from another ambrosia beetle, Xylosandrus crassiusculus. In the no-choice assays, mycangia of foundress females of X. bispinatus harbored significant colony-forming units of, and natal galleries that they produced were colonized with, the respective Raffaelea symbionts; with each of these fungi, reproduction, fecundity and survival of the beetle were positively impacted. However, no fungus was recovered from, and reproduction did not occur on, the A. roeperi and no symbiont diets. These results highlight the flexible nature of the ambrosial symbiosis, which for X. bispinatus includes a fungus with which it has no evolutionary history. Although the “primary” symbiont of the neotropical X. bispinatus is unclear, it is not the Asian R. lauricola.

Avocado trees in Florida and California are under attack, respectively, from laurel wilt and Fusarium dieback, two diseases caused by fungi that live in symbiosis with ambrosia beetle species. As a first step to identify possible bacteria that can be utilized as biocontrol agents against these important diseases of avocados, we isolated microorganisms from avocado trees in Florida to determine their potential for use as biocontrol antagonists against the pathogens responsible for laurel wilt and Fusarium dieback. In addition, we assessed the potential of other strains not isolated from avocado to determine their effectiveness as biocontrol antagonists. A total of 50 strains were identified as strong antagonists against the laurel wilt pathogen, Raffaelea lauricola. Fifteen of the most active strains were, in turn, evaluated for antagonism against Fusarium euwallaceae, the causal agent of Fusarium dieback on avocados. Four strains representing three Paenibacillus species and one Bacillus species were found to be active against both R. lauricola and F. euwallaceae. This study is the first to report antifungal or antagonist activity of bacterial strains effective against avocado pathogens vectored by ambrosia beetles, and it is also the first to report the effectiveness of Paenibacillus thiaminolyticus or Paenibacillus apiarius against a phytopathogen.

Banisia myrsusalis Walker (Lepidoptera: Thyrididae) has been regarded as the most damaging pest of sapodilla, Manilkara zapota (L.) van Royen (Sapotaceae), in Florida, where it causes extensive damage to blooms. Two commercial sapodilla groves were surveyed for lepidopteran eggs and larvae affecting floral buds and mature flowers. All collected specimens were raised in the laboratory until adult emergence. A careful revision of reared individuals and specimens deposited in institutional collections since 1990 brought into question the identity of Banisia species affecting sapodilla in southern Florida. Specimens initially identified as B. myrsusalis are herein re-identified as Banisia argutula Whalley, based on female and male genitalic characters. Total DNA was extracted from 2 specimens raised in the survey and the COI gene sequence determined and deposited in GenBank. Larvae of B. argutula were observed chewing holes in the base of floral buds or mature flowers, entering the flower, and consuming all floral structures except the sepals. A single larva would tend to clump several flowers and floral buds together by using silk. Larvae could also fold leaves or bore into the fruit and could complete their immature development feeding on folded leaves, flowers, or inside a fruit. In contrast, B. myrsusalis is reported as strictly a leaf-folder. Banisia myrsusalis was found to be a minor part of the sapodilla pest complex. Banisia argutula was the dominant sapodilla borer in southern Florida. Resumen Banisia myrsusalis Walker (Lepidoptera: Thyrididae) ha sido considerado como la plaga mas danina del zapote Manilkara zapota (L.) van Royen (Sapotaceae) en Florida, causando un excesivo dano a las florez. Dos huertos comerciales de zapote fueron monitoreados debido a que huevos y larvas de lepidopteros afectaban los brotes florales y las flores maduras. Todos los especimenes colectados fueron criados en el laboratorio hasta la emergencia del adulto. Una revision minuciosa de los especimenes criados y de los especimenes depositados en colecciones institucionales desde 1990, puso en cuestion la identidad de la especie de Banisia que afectaba al zapote en el sur de Florida. Especimenes identificados inicialmente como B. myrsusalis son aqui re-identificados como Banisia argutula Whalley basado en las caracteristicas de la genitalia del macho y la hembra. El ADN total fue extraido de dos especimenes criados en el estudio y la secuencia de COI fue determinada y depositada en GeneBank. Las larvas de B. argutula fueron observadas masticando agujeros en la base de los brotes florales y flores maduras, entrando a las flores y consumiendo todas las estructuras florales excepto los sepalos. Una simple larva tiende a agrupar varias flores y brotes florales usando seda. Las larvas pueden incluso enrollar las hojas o perforar dentro de los frutos, y pueden completar su desarrollo inmaduro alimentandose de hojas dobladas, flores o dentro de un fruto. En contraste, B. mysusalis esta reportada estrictamente como enrollador de hojas. Banisia myrsusalis fue encontrada como una parte minoritaria del complejo de plagas de zapote. Banisia argutula es el perforador de zapote comun en el Sur de Florida. View this article in BioOne

Laurel wilt kills American members of the Lauraceae plant family, including avocado (Persea americana). The disease threatens commercial production in the United States and other countries, and currently impacts the avocado industry in Florida. As laurel wilt spreads, the National Germplasm Repository for avocado in Miami (USDA-ARS) and commercial and residential production in other states (e.g., California and Hawaii), U.S. protectorates (Puerto Rico), and other countries are at risk. In the United States, value-added production of avocado of more than $1.3 billion/year is threatened. This recovery plan was produced as part of the National Plant Disease Recovery System (NPDRS), called for in Homeland Security Presidential Directive Number 9 (HSPD-9) to insure that the tools, infrastructure, communication networks, and capacity required to mitigate the impact of high-consequence plant disease outbreaks are such that a reasonable level of crop production is maintained. It is intended to provide a brief primer on the disease, assess the status of critical recovery components, and identify disease management research, extension, and education needs.

Mallodon dasystomus Say (Coleoptera: Cerambycidae: Prioninae) is a pest of hardwood trees in the southern United States that recently began attacking trees in avocado groves in Miami-Dade County, Florida. The larvae feed hidden inside the tree, and adult attractants have not been commercialized; consequently, this species is difficult to find in field environments. It was of interest to consider the potential use of insect acoustic detection devices to help survey the magnitude and locations M. dasystomus populations in commercial avocado groves so that the extent of their economic damage could be estimated. An insect acoustic detection system was tested in 2 avocado groves on 11 trees suspected of harboring infestations. Four infested trees were identified and 6 were correctly classified as uninfested. One uninfested tree was classified as infested, possibly due to the occurrence of wind during signal recording. The use of acoustic methods to detect M. dasystomus can be of benefit in estimating its economic damage to the Florida avocado industry already facing losses from laurel wilt, caused by Raffaelea lauricola, Harrington, Fraedrich, and Aghayeva (Ophiostomataceae), vectored by redbay ambrosia beetle Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae) (Ploetz et al. 2017), and Fusarium (Hypocreaceae) dieback, vectored by Euwallacea nr. fornicatus (Coleoptera: Curculionidae) (Carrillo et al. 2016; Kendra et al. 2017).

The ambrosia beetle Xyleborus volvulus Fabricius has been reported as a potential vector of the plant pathogen Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva that is affecting avocado orchards in South Florida. In this study, we examined its life cycle, process of gallery formation, gallery structure, and fungal associates by rearing one generation on avocado sawdust medium under control conditions. The adult foundress excavated a vertical tunnel that constituted the main gallery with a length of 2.5 cm, followed by the construction of up to six secondary galleries with a total length of 4.4 cm. The time period for one generation (egg to adult) was 28 days. Teneral males emerged 3 days after the emergence of the first females. The F(1) generation did not significantly contribute to gallery expansion. Four species of Raffaelea and nine yeast species were recovered from galleries and beetles. Raffaelea arxii and Candida berthetii were the most frequent symbionts recovered from new adults and galleries. Candida berthetii dominated during the early stages of the gallery development, whereas R. arxii was most frequent in later stages. Other Raffaelea species were inconsistently isolated from galleries, which suggests a strong association between Xyleborus volvulus and both R. arxii and C. berthetii. These results suggest that R. arxii is the primary nutritional symbiont of X. volvulus and that yeast species may be pioneer colonizers that assist with the growth of fungal symbionts. IMPORTANCE Ambrosia beetles cultivate fungi in tunnels bored into weakened host trees. This obligate interaction is required for their survival as beetles feed on these symbiotic fungi, and the fungi benefit from transportation by the beetles. Xyleborus volvulus carries many nonpathogenic symbionts; however, recently the acquisition of Raffaelea lauricola (the causal agent of a lethal vascular disease of lauraceous trees) by this beetle has altered its status from wood degrader to potential pest in avocado. We conducted a study to understand the relationship of this beetle and its fungal associates. Our results show that X. volvulus has a multipartite flexible association with different Raffaelea species. The lack of fidelity in the mutualistic association may explain the acquisition of R. lauricola. Knowing the beetle biology and its mutualistic interactions furthers an understanding of the beetle’s role as a potential vector and in disease transmission.

Laurel wilt and Fusarium dieback are vascular diseases caused by fungal symbionts of invasive ambrosia beetles (Coleoptera: Curculionidae: Scolytinae). Both diseases threaten avocado trees in Florida. Redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of the laurel wilt pathogen, Raffaelea lauricola, but in recent years this symbiont has been transferred laterally to at least nine other species of ambrosia beetle, which now comprise a community of secondary vectors. Dieback disease, caused by Fusarium spp. fungi, is spread by shot hole borers in the Euwallacea fornicatus species complex. In this study, we conducted field tests in Florida avocado groves to compare efficacy of four trap designs for detection of Scolytinae. Treatments included an 8-funnel Lindgren trap, black 3-vane flight interception trap, green 3-vane interception trap, white sticky panel trap, and an unbaited sticky panel (control). In two tests targeting E. nr. fornicatus and X. glabratus, traps were baited with a two-component lure (α-copaene and quercivorol). In a test targeting other species, traps were baited with a low-release ethanol lure. For E. nr. fornicatus, sticky panels and black interception traps captured significantly more beetles than Lindgren traps; captures with green traps were intermediate. With ethanol-baited traps, 20 species of bark/ambrosia beetle were detected. Trap efficacy varied by species, but in general, sticky traps captured the highest number of beetles. Results indicate that sticky panel traps are more effective for monitoring ambrosia beetles than Lindgren funnel traps, the current standard, and may provide an economical alternative for pest detection in avocado groves.

Carrillo, J.D., Rugman-Jones, PF., Husein, D., Stajich, J.E., Kasson, M.T., Carrillo, D., Stouthamer, R., and Eskalen, A. 2019. Members of the Euwallacea fornicatus species complex exhibit promiscuous mutualism with ambrosia fungi in Taiwan. A number of ambrosia beetles have come to prominence in recent years because of the damage they inflict on a variety of trees within invaded habitats across the globe. Ambrosia beetles rely on symbiotic microorganisms, mainly fungi, as a dedicated food source and carry those microorganisms around with them within specialized organs termed mycangia. Investigation of members of the Euwallacea fornicatus species complex and their fungal symbionts in Taiwan revealed promiscuous symbioses with ambrosial Fusaria clade (AFC) members, Graphium spp., and Paracremonium spp. based on co-phylogenetic analyses. For AFC members, a novel diagnostic PCR assay targeting mating type genes MAT1-1-1 and MAT1-2-1 was developed and validated by amplicon size and sequencing. Mating type screening of AFC members revealed the isolates screened are all heterothallic (self-sterile), with both MAT types represented and recovered from fungi vectored by E. fornicatus (tea shot hole borer), E. kuroshio (Kuroshio shot hole borer), and E. whitfordiodendrus (polyphagous shot hole borer) in Taiwan. Members of the Euwallacea fornicatus species complex and the variety of ambrosia fungi they utilize further confirms that their relationship with these fungi are more likely promiscuous in native areas, as opposed to strictly obligate to a specific combination of fungi as observed in invaded areas.

The tea shot-hole borer (THSB), a member of the Euwallacea fornicatus (Eichhoff 1868) complex of species, harboring the plant pathogenic symbiotic fungi (AF-6, AF-8, and Fusarium sp.) (Curculionidae: Scolytinae) attacks avocado (Persea americana Miller) and other tree species in Florida. Currently, their management is limited to prevention and sanitation; therefore, the development of novel control alternatives is critical to mitigate pest outbreaks and avoid massive crop losses. Here, we report on the antifungal activity of copper nanoparticles (Cu-NPs) against the beetle/fungus complex and their effect on the beetle's reproduction. The results revealed that the synthesized Cu-NPs were pure metallic Cu with an average size of 240.88 ± 62.66 nm measured by electron microscopy. The antifungal test for symbionts showed that 0.75 mg/mL of Cu-NPs caused growth inhibition above 60%. However, strong alterations in the morphology of fungal cells were observed at Cu-NPs concentrations as low as 0.1 mg/mL. Additionally, treatments with 0.25, 0.5, and 1 mg/mL of Cu-NPs led to a reduction in offspring production in a concentration dependent manner. According to our findings, the application of Cu-NPs could be potentially considered as an alternative for the control of the beetle-fungi complex or even be integrated into novel disease management strategies.

Pitaya or Dragon Fruit is a recent crop in South Florida; it belongs to the Cactaceae family, and its scientific name is Hylocereus undatus (Haworth) Britton & Rose. This fruit crop has grown rapidly and shows a good potential for commercialization. This fact sheet contains some of the pests and beneficial insects associated with it.

BACKGROUND Caribbean fruit fly (Caribfly) is a serious economic insect pest because of development of larvae that hatch from eggs oviposited into fruits by female adults. This study assessed the virulence of twelve entomopathogenic nematode (EPN) isolates to Caribfly in laboratory bioassays as a starting point toward evaluation of management strategies for the fruit-to-soil-dwelling stages of A. suspensa in fields infested by Caribfly. RESULTS Inoculation of A. suspensa with 1 mL of ca 200 IJs larva−1 killed Caribfly at either larval or pupal stage. Pupae were more resistant to EPN infections than larvae. Adult emergence from inoculated pupae in soil microcosms was significantly lower than that observed in filter paper assays. Longest or largest steinernematids suppressed emergence of more adult Caribfly from pupae in soils, whereas shorter heterorhabditids were more infectious to Caribfly larvae. The highest mortalities of A. suspensa were caused by exotic nematodes Steinernema feltiae and Heterorhabditis bacteriophora, followed by the native Heterorhabditis indica and the exotic Steinernema carpocapsae. CONCLUSION Entomopathogenic nematodes reduced the development of Caribfly larvae and pupae to adult in our bioassays, suggesting that EPNs have potential for biological control of A. suspensa. Future work will assess management strategies, using the virulent EPNs, in orchards infested by A. suspensa. © 2016 Society of Chemical Industry

Several species of the ambrosia beetle Euwallacea (Coleoptera: Curculionidae: Scolytinae) cultivate Ambrosia Fusarium Clade (AFC) species in their galleries as a source of food. Like all other scolytine beetles in the tribe Xyleborini, Euwallacea are thought to be obligate mutualists with their fungal symbionts. Published diversification-time estimates suggest that the Euwallacea – Fusarium symbiosis evolved once approximately 21 million years ago. Female Euwallacea possess paired oral mycangia within which foundresses transport their Fusarium symbiont vertically from their natal gallery to new woody hosts. During the past two decades, exotic Asian Euwallacea – Fusarium mutualists have been introduced into the United States, Israel and Australia. Because these invasive pests attack and can reproduce on living woody hosts, they pose a serious threat to native forests, urban landscapes and the avocado industry.

Parasitoid wasps reproduce by laying their eggs on or inside of a host insect, which triggers a defense response in the host insect that kills the developing wasp. To counteract the host's lethal response, some parasitoid wasps are associated with symbiotic viruses that alter host metabolism and development to promote successful development of the wasp embryo. These symbiotic viruses display a number of characteristics that differ from those of pathogenic viruses, but are poorly understood with the exception of one group, the polydnaviruses. Here, we characterize the genome of a non-polydnavirus associated with parasitoid wasps, Diachasmimorpha longicaudata rhabdovirus (DlRhV), and assess its role as a potential mutualistic virus. Our results show that the DlRhV genome contains six open reading frames (ORFs). Three ORFs show sequence homology to known viral genes and one ORF encodes a previously identified protein, called parasitism-specific protein 24 (PSP24), that has been hypothesized to play a role in promoting successful parasitism by D. longicaudata. We constructed a phylogeny that shows that DlRhV is most closely related to other insect-infecting rhabdoviruses. Finally, we report that DlRhV infection does not occur in all populations of D. longicaudata, and is not required for successful parasitism.

Recent molecular studies have found that the ambrosia beetle Euwallacea fornicatus Eichhoff (Coleoptera: Curculionidae: Scolytinae) is a complex of cryptic species, each carrying a different species of symbiotic fungus, in the genus Fusarium, which they farm within galleries inside woody hosts. Several of these beetle species have become invasive pests around the world for attacking and infecting healthy trees with their phytopathogenic fungal symbionts. Diet and rearing protocols were developed for two members of the E. fornicatus species complex, polyphagous shot hole borer (PSHB) and tea shot hole borer (TSHB), using sawdust from host trees, allowing collection of data on beetle biology, phenology and sex ratios. Adults developed within 22 days at 24 °C. Single PSHB or TSHB foundresses averaged 32.4 and 24.7 adult female offspring, respectively, and up to 57 and 68 female adults within 6–7 weeks. A strong predictor of the number of offspring in a colony was the number of entry holes. Average sex ratios (% male) for PSHB and TSHB, respectively, were 7.4% and 7.2%. Being haplodiploid, virgin PSHB foundresses were able to produce and mate with male offspring, then subsequently produce female offspring, confirming that they have arrhenotokous reproduction. A cold tolerance study found significant mortality rates among PSHB colonies exposed to −5° or −1 °C but not colonies exposed to 0°, 1° or 5 °C. Given Hamilton's local mate competition (LMC) theory, a number of LMC predictions were violated. PSHB sex ratios were not affected by the number of foundresses; approximately 14% of broods did not contain males; males did not usually eclose before females but eclosed around the same time (22–23 days); and PSHB males were found walking outside of their natal galleries on the trunk of a heavily infested tree in the field. Alternatives to LMC are considered, such as early forms of sociality (maternal care, cooperative brood care), local resource enhancement and kin selection.

The lychee erinose mite, Aceria litchii (Keifer) (Acari: Eriophyidae), is an important pest of lychee (Litchi chinensis Sonn.; Sapindaceae). Its recent interception in Lee County, Florida, USA, resulted in a quarantine whereby no lychee material, including fruit, can be transferred outside the county. Therefore, there is an urgent need for post-harvest treatments that can disinfest the fruit of the pest. Results of this study indicate that post-harvest dips in paraffinic oil solutions, 3 and 5%, for 60 s can achieve complete disinfestation of lychee fruit of A. litchii motile stages as well as other arthropods. In both ‘Mauritius' and ‘Brewster’ cultivars the treatments had a beneficial effect on fruit quality for the first 10 d after treatment. Post-harvest dips in paraffinic oil showed effective control of A. litchii without a noticeable reduction in fruit quality. Hence, this treatment might allow growers in Lee County to transport lychee fruit outside the quarantine zone.

The lychee erinose mite (LEM), Aceria litchii (Keifer) is a serious pest of lychee (Litchi chinensis Sonn.). LEM causes a type of gall called &lsquo, erineum&rsquo, (abnormal felty growth of trichomes from the epidermis), where it feeds, reproduces and protects itself from biotic and abiotic adversities. In February of 2018, LEM was found in a commercial lychee orchard on Pine Island, Florida. Infestations were recorded on young leaves, stems, and inflorescences of approximately 30 young trees (1.5&ndash, 3.0 yrs.) of three lychee varieties presenting abundant new growth. Although LEM is present in Hawaii, this mite is a prioritized quarantine pest in the continental USA and its territories. Florida LEM specimens showed small morphological differences from the original taxonomic descriptions of Keifer (1943) and Huang (2008). The observed differences are probably an artifact of the drawings in the original descriptions. Molecular comparisons were conducted on the DNA of LEM specimens from India, Hawaii, Brazil, Taiwan, Australia and Florida. The amplified COI fragment showed very low nucleotide variation among the locations and thus, could be used for accurate LEM identification. The ITS1 sequences and partial 5.8S fragments displayed no nucleotide differences for specimens from any of the locations except Australia. Consistent differences were observed in the ITS2 and 28S fragments. The ITS1-ITS2 concatenated phylogeny yielded two lineages, with Australia in one group and Hawaii, India, Brazil, Florida and Taiwan in another. Specimens from Taiwan and Florida present identical ITS and rDNA segments, suggesting a common origin, however, analysis of additional sequences is needed to confirm the origin of the Florida population.

Invasive species, those that are nonnative and cause economic damage, are one of the main threats to ecosystems around the world. Ambrosia beetles are some of the most common invasive insects. Currently, severe economic impacts have been increasingly reported for all the invasive shot hole borers in South Africa, California, Israel, and throughout Asia. This 7-page fact sheet written by Demian F. Gomez, Jiri Hulcr, and Daniel Carrillo and published by the School of Forest Resources and Conservation describes shot hole borers and their biology and hosts and lists some strategies for prevention and control of these pests. http://edis.ifas.ufl.edu/fr422

Mutualistic symbiosis and eusociality have developed through gradual evolutionary processes at different times in specific lineages. Like some species of termites and ants, ambrosia beetles have independently evolved a mutualistic nutritional symbiosis with fungi, which has been associated with the evolution of complex social behaviors in some members of this group. We sequenced the transcriptomes of two ambrosia complexes (Euwallacea sp. near fornicatus&ndash, Fusarium euwallaceae and Xyleborus glabratus&ndash, Raffaelea lauricola) to find evolutionary signatures associated with mutualism and behavior evolution. We identified signatures of positive selection in genes related to nutrient homeostasis, regulation of gene expression, development and function of the nervous system, which may be involved in diet specialization, behavioral changes, and social evolution in this lineage. Finally, we found convergent changes in evolutionary rates of proteins across lineages with phylogenetically independent origins of sociality and mutualism, suggesting a constrained evolution of conserved genes in social species, and an evolutionary rate acceleration related to changes in selective pressures in mutualistic lineages.

Laurel wilt is a disease threatening the avocado industry in Florida. The causative agent of the disease is a fungus vectored by ambrosia beetles that bore into the trees. Until recently, management strategies for the vectors of the laurel wilt fungus relied solely on chemical control and sanitation practices. Beneficial entomopathogenic fungi (EPF) are the most common and prevalent natural enemies of pathogen vectors. Laboratory experiments demonstrated that commercial strains of EPF can increase the mortality of the primary vector, Xyleborus glabratus, and potential alternative vectors, Xylosandrus crassiusculus, Xyleborus volvulus and Xyleborus bispinatus (Coleoptera: Curculionidae: Scolytinae). Our study provides baseline data for three formulated commercially-available entomopathogenic fungi used as potential biocontrol agents against X. crassiusculus, X. volvulus and X. bispinatus. The specific objectives were to determine: (1) the mean number of viable spores acquired per beetle species adult after being exposed to formulated fungal products containing different strains of EPF (Isaria fumosorosea, Metarhizium brunneum and Beauveria bassiana); and (2) the median and mean survival times using paper disk bioassays. Prior to being used in experiments, all fungal suspensions were adjusted to 2.4 × 106 viable spores/mL. The number of spores acquired by X. crassiusculus was significantly higher after exposure to B. bassiana, compared to the other fungal treatments. For X. volvulus, the numbers of spores acquired per beetle were significantly different amongst the different fungal treatments, and the sequence of spore acquisition rates on X. volvulus from highest to lowest was I. fumosorosea > M. brunneum > B. bassiana. After X. bispinatus beetles were exposed to the different suspensions, the rates of acquisition of spores per beetle amongst the different fungal treatments were similar. Survival estimates (data pooled across two tests) indicated an impact for each entomopathogenic fungus per beetle species after exposure to a filter paper disk treated at the same fungal suspension concentration. Kaplan–Meier analysis (censored at day 7) revealed that each beetle species survived significantly shorter in bioassays containing disks treated with EPF compared to water only. This study demonstrated that ambrosia beetles associated with the laurel wilt pathogen in avocados are susceptible to infection by EPF under laboratory conditions. However, the EPF needs to be tested under field conditions to confirm their efficacy against the beetles.

Ambrosia beetles harbor fungal symbionts that serve as food sources for larvae and adults. These beetles lay their eggs along tunnels in xylem sapwood, which is the substrate for fungal growth. Symbiotic fungi of the genus Raffaelea found in invasive and indigenous ambrosia beetles include the highly virulent plant pathogen Raffaelea lauricola affecting members of the Lauraceae family. R. lauricola is responsible for the deaths of > 500 million trees since 2005. Infection by as few as 100 spores can kill a healthy tree within months. Our data show that R. lauricola is cold-adapted with optimal growth between 16 and 26 °C, with little to no growth at temperatures ≥ 30 °C. The fungus is halophilic and shows a dramatic decrease in growth at pH ≥ 6.8. Fungicide resistance profiling revealed sensitivity of R. lauricola to prochloraz, dichlorofluanid, most conazoles, dithiocarbamates, and zineb (zinc fungicide), whereas the related species Raffaelea arxii showed more limited fungicide sensitivity. Entomopathogenic fungi potentially useful for beetle control were generally highly resistant to most fungicides tested. Coupling pH decreased the concentration for 95% inhibition of fungal growth (IC95) of the most potent R. lauricola fungicides by 3–4-fold. Use of avocado bark plug insect bioassays revealed that commercially available Beauveria bassiana can be used as a biological control agent capable of effectively killing the beetle vectors. These data provide simple and practical recommendations to specifically target R. lauricola while having minimal effects on other symbiotic and entomopathogenic fungi, the latter of which can be used to manage the beetle vectors.

Nutritional mutualisms that ambrosia beetles have with fungi are poorly understood. Although these interactions were initially thought to be specific associations with a primary symbiont, there is increasing evidence that some of these fungi are associated with, and move among, multiple beetle partners. We examined culturable fungi recovered from mycangia of ambrosia beetles associated with trees of Persea humilis (silk bay, one site) and P. americana (avocado, six commercial orchards) that were affected by laurel wilt, an invasive disease caused by a symbiont, Raffaelea lauricola, of an Asian ambrosia beetle, Xyleborus glabratus. Fungi were isolated from 20 adult females of X. glabratus from silk bay and 70 each of Xyleborus affinis, Xyleborus bispinatus, Xyleborus volvulus, Xyleborinus saxesenii, and Xylosandrus crassiusculus from avocado. With partial sequences of ribosomal (LSU and SSU) and nuclear (β-tubulin) genes, one to several operational taxonomic units (OTUs) of fungi were identified in assayed individuals. Distinct populations of fungi were recovered from each of the examined beetle species. Raffaelea lauricola was present in all beetles except X. saxesenii and X. crassiusculus, and Raffaelea spp. predominated in Xyleborus spp. Raffaelea arxii, R. subalba, and R. subfusca were present in more than a single species of Xyleborus, and R. arxii was the most abundant symbiont in both X. affinis and X. volvulus. Raffaelea aguacate was detected for the first time in an ambrosia beetle (X. bispinatus). Yeasts (Ascomycota, Saccharomycotina) were found consistently in the mycangia of the examined beetles, and distinct, putatively co-adapted populations of these fungi were associated with each beetle species. Greater understandings are needed for how mycangia in ambrosia beetles interact with fungi, including yeasts which play currently underresearched roles in these insects.

Amblyseius tamatavensis Blommers (Acari: phytoseiidae) is reported for the first time in the United States of America, based on specimens collected from Laportea aestuans (Urticaceae) and Solanum americanum (Solanaceae) where it was found in association with the banded-wing whitefly Trialeurodes abutiloneus (Haldeman) (Hemiptera: Aleyrodidae) in southern Florida. Further observations confirmed that this predator can feed and reproduce on sweet potato whitefly, Bemisia tabaci (Gennadius), and ficus whitefly, Singhiella simplex (Singh). This species may be an important predator as a potential biological control agent of whiteflies. Amblyseius tamatavensis from Florida was re-described and illustrated based on female specimens to access intraspecific variation as well as to secure further diagnosis. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.

Brevipalpus mites (Acari: Tenuipalpidae) carrying citrus leprosis virus are considered serious quarantine pests. The objective of this research was to clarify the effectiveness of commonly used fruit cleaners, soaps, waxes, and mechanical brushing techniques (alone and in combination) on removal and/or mortality of mites (percentage of density reduction) from infested citrus fruits. Six bioassays were conducted with infested lemons, Citrus limon (L.) Burm.f. (Sapindales: Rutaceae), using non-virulent Brevipalpus yothersi Baker as a model species. In each bioassay, all stages (eggs, nymphs, and adults) of B. yothersi were recorded before and after treatment. Results indicated that none of the treatments provided 100% reduction of all stages of mites, as would be required for quarantine treatments. In general, mite reduction following single treatments (soap rinse, brushing, or waxing alone) was not significantly different from reduction obtained with a water drench control. However, several combination treatments were successful in achieving ~90% reduction of mites, particularly those that included application of a food-grade wax coating. Therefore, a combination of treatments, including a soap wash and mechanical brushing followed by a wax coating, may be the most effective method to achieve significant reduction of all stages of Brevipalpus mites from infested citrus.