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The Caribbean fruit fly, Anastrepha suspensa (Loew) (Diptera: Tephritidae), is a quarantine pest of Citrus spp. and a production pest of guava and other specialty fruits in Florida. Effective monitoring lures and traps are needed for early pest detection and timely initiation of control measures. As part of a continued effort to identify attractive synthetic lures for the Caribbean fruit fly, we conducted field tests in Homestead, Florida to compare the efficacy and longevity of commercial 2- and 3-component cone lures (2C [ammonium acetate and putrescine], 3C [ammonium acetate, putrescine, and trimethylamine]), the current standards used by regulatory agencies, versus the traditional liquid protein bait consisting of hydrolyzed torula yeast and borax as a positive control. Additional lures were also field-aged and periodically brought into the laboratory to quantify residual chemical contents. Traps baited with the torula yeast-borax mixture captured the highest mean number of A. suspensa, and traps baited with the commercial 2C lures captured more flies than the 3C lures. Traps baited with torula yeast-borax also captured the highest number of nontarget Diptera. Captures with all three treatments were significantly biased toward females. Attractiveness of the 2C lure began to drop after 6–8 wk, and the 3C lure after 5–6 wk. Overall, these data suggest that the 2C cone lure is more attractive to A. suspensa than the 3C cone lure under field conditions in south Florida, and that the 2C lures are attractive for up to 8 wk.

Megaselia halterata (Wood) (Diptera: Phoridae) is a major pest of cultivated white button mushrooms, Agaricus bisporus (J.E.Lange) Emil J. Imbach (Agaricales: Agaricaceae), in the United States. Th...

Native to the northeast USA, highbush blueberry is a crop domesticated for close to 100 years and that has been selected mainly for high yields and bigger fruit. We hypothesized that, due to domestication and associated agronomic selection (i.e., cultivation practices), cultivated blueberries differ from their wild ancestors in fruit volatile emissions, affecting the response of a frugivorous pest. To test this hypothesis, we compared the attraction of adult spotted-wing drosophila (Drosophila suzukii) to wild and cultivated blueberry fruit volatiles in choice assays. We also conducted headspace volatile chemical analysis and electroantennographic detection (EAD) analysis to identify and quantify any antennally active compounds. For this, fruit from wild and cultivated blueberries, growing in proximity, was sampled from six farms located in the Pinelands National Reserve (New Jersey, USA)—a blueberry-producing region with a forest understory consisting largely of wild blueberries. On a per gram basis, we found that wild blueberries are more attractive to D. suzukii flies and have higher volatile emission rates than cultivated blueberries. Nine EAD-active compounds from wild blueberries (isobutyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl 3-methylbutyrate, hexanal, isoamyl acetate, 3-hydroxybutanone (acetoin), 6-methyl-5-hepten-2-one, and 1-hexanol) were attractive individually and as a blend to D. suzukii flies. However, a 4-component blend composed of isoamyl acetate, acetoin, 6-methyl-5-hepten-2-one, and 1-hexanol was more attractive to D. suzukii than the 9-component blend. Altogether, our results show that the domestication/cultivation of blueberries is associated with lower rates of fruit volatile emissions, which has resulted in decreased attraction of a frugivorous pest, D. suzukii.

This study examined electrophysiological responses of the Australian budworm moth Helicoverpa punctigera, to heliothine sex pheromone components, via single sensillum recordings (SSR), and examined male neuroanatomy using confocal microscopy and 3D imaging tools. We found that male H. punctigera have three distinct regions of the macroglomerular complex (MGC) in the antennal lobe. Male antennae have only two functional types of sensilla trichoidea (A and C) and type A sensilla contain an olfactory sensory neuron (OSN) that responds to the major sex pheromone component (Z)-11-hexadecenal (Z11-16:Ald) with axons projecting to the cumulus of the macroglomerular complex (MGC) in the antennal lobe. Type C sensilla contained large-spiking receptor neurons which responded primarily to (Z)-9-tetradecenal (Z9-14:Ald) and to a lesser degree to (Z)-11-hexadecenol (Z11-16:OH). These were co-compartmentalized with small-spiking receptor neurons in type C sensilla which responded strongly to Z9-14:Ald and (Z)-9-hexadecenal (Z9-16:Ald), and to a lesser degree to (Z)-11-hexadecenyl acetate (Z11-16:OAc) and Z11-16:OH. Axons from the two co-localized neurons in Type C sensilla projected to the two small MGC units, the dorsomedial anterior and dorsomedial posterior, respectively. In wind tunnel assays, the addition of Z9-16:Ald to an otherwise attractive blend completely shut down male H. punctigera upwind flight.

Spotted-wing drosophila (SWD), Drosophila suzukii Matsumura (Diptera: Drosophilidae), is an invasive pest of thin-skinned fruits in the United States. Monitoring traps are an integral part of SWD integrated pest management, allowing early detection and timely management of this pest. An ideal monitoring trap should be easy to use, effective in capturing SWD, sensitive and selective to male SWD which are easy to identify due to their spotted wings, and able to predict fruit infestation from trap captures. Deli-cup-based liquid traps (grower standard), which make in-situ observations difficult, were compared with red-panel sticky traps, both baited with commercial lures (Scentry, Trécé Broad-Spectrum (BS), and Trécé High-Specificity (HS)), across several US states in blueberries (lowbush and highbush), blackberry, raspberry, and cherry crops during 2018 and 2021. Results showed that red-panel traps effectively captured SWD, were able to detect male SWD early in the season while also being selective to male SWD all season-long, and in some cases linearly related male SWD trap captures with fruit infestation. Scentry and Trécé BS lures captured similar numbers of SWD, though Trécé BS and Trécé HS were more selective for male SWD in red panel traps than liquid traps in some cases. In conclusion, due to its ease of use with less processing time, red-panel traps are promising tools for detecting and identifying male SWD in-situ and for predicting fruit infestation. However, further research is needed to refine the trap captures and fruit infestation relationship and elucidate the trap-lure interactions in berry and cherry crops.

The invasive spotted-wing drosophila, Drosophila suzukii (Matsumura), is a major pest of soft-skinned fruits. Since its introduction into North America and Europe, significant progress has been made in understanding the volatile cues used by this fly during food, oviposition site, and mate finding. Despite this progress, commercially available lures are non-selective. Here, we tested two Hanseniaspora uvarum (Niehaus) yeast compounds (isoamyl acetate and isobutyl acetate) and a leaf compound β-cyclocitral alone and in combination with a blend of four fermentation compounds (‘Fermentation lure’: acetic acid, ethanol, methionol, and acetoin) to improve D. suzukii attraction and selectivity. In laboratory assays, males and females were attracted to all seven individual compounds, although in electrophysiological assays, their antennae exhibited a dose-dependent response to only four of these compounds. In two-choice cage studies, the Fermentation lure was more attractive to D. suzukii than water controls, whereas β-cyclocitral and the mixture of isoamyl acetate and isobutyl acetate were not attractive in this larger-cage study. Moreover, adding the two-component H. uvarum compound blend to the Fermentation lure reduced D. suzukii attraction to the Fermentation blend. When these experiments were repeated in blueberry, raspberry, blackberry, and cherry orchards across several states in the United States over 2 yr, similar outcomes were observed: β-cyclocitral or the mixture of the H. uvarum blend did not improve the attractiveness of the Fermentation lure or its selectivity. This study demonstrates that cues from different sources may interfere with each other and reduce D. suzukii attraction to otherwise attractive odor combinations.

Gravid female mushroom sciarid flies, Lycoriella ingenua (Dufour:1839) (Diptera:Sciaridae), were confirmed in laboratory experiments as vectors for the fungal pathogen Trichoderma aggressivum f. aggressivum (Samuels and Gams), causal agent of mushroom green mold disease in mushroom farming. The gravid females acquired the fungal spores when exposed to T. aggressivum cultures, which was confirmed by scanning electron microscopy, the flies vectored T. aggressivum onto clean agar petri dishes, confirmed by new fungal colonies growing on the media and molecular analysis (PCR). Significantly, more T. aggressivum colonies formed on the dishes when flies were left to vector the pathogen for 30 h, as opposed to 18 h. One gravid female fly was able to initiate up to 32 T. aggressivum colonies in a 0.03 m3 area. Frass deposits of mushroom sciarid fly larva reared on T. aggressivum contained viable spores, detected through fungal subcultures and molecular analysis (PCR), confirming that larvae can also vector the fungus. This study supports the heretofore anecdotal evidence that mushroom sciarid flies are part of green mold disease epidemiology on mushroom farms.

The effect of delayed female mating for the mushroom fungus gnat Lycoriella ingenua is investigated. We examine the effect of delaying female mating on the fertility and egg viability of female flies that have a mating delay of 0–5 days after emergence. Male fly age is held constant. Female age does not impact male acceptance and most flies copulate within seconds of pairing. We find that female flies experiencing mating delays of 0–4 days after emergence lay a similar number of eggs onto artificial substrates. Females that experience a mating delay of 5 days lay 54% fewer eggs than those that mate on day 0 (day of emergence). There is no effect of mating delay on the percentage of larvae that emerge. The results of the present study indicate that mating delays have little effect on the fertility or fecundity of the mushroom fungus pest L. ingenua.

Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) also known as spotted-wing drosophila (SWD), is a pest native to Southeast Asia. In the last few decades, the pest has expanded its range to affect all major European and American fruit production regions. SWD is a highly adaptive insect that is able to disperse, survive, and flourish under a range of environmental conditions. Infestation by SWD generates both direct and indirect economic impacts through yield losses, shorter shelf life of infested fruit, and increased production costs. Fresh markets, frozen berries, and fruit export programs have been impacted by the pest due to zero tolerance for fruit infestation. As SWD control programs rely heavily on insecticides, exceedance of maximum residue levels (MRLs) has also resulted in crop rejections. The economic impact of SWD has been particularly severe for organic operations, mainly due to the limited availability of effective insecticides. Integrated pest management (IPM) of SWD could significantly reduce chemical inputs but would require substantial changes to horticultural management practices. This review evaluates the most promising methods studied as part of an IPM strategy against SWD across the world. For each of the considered techniques, the effectiveness, impact, sustainability, and stage of development are discussed.

The mushroom phorid fly, Megaselia halterata (Wood), is a common pest of mushroom production in many parts of the world. Due to the reduced availability of conventional insecticides for mushroom production, M. halterata has recently developed into a major pest in the top mushroom-producing county in the United States (Chester County, PA). Mushrooms are grown entirely indoors, and though larval development of M. halterata occurs in the mushroom-growing substrate, adult flies have been captured both inside and outside of the facilities. Here, we investigated three factors that might contribute to their growth and development. 1) The effects of ambient temperature (15–30°C) and relative humidity (RH; 21–98%) on adult M. halterata lifespan, 2) the effect of spawned compost stage (freshly inoculated with spawn vs 14-d spawned compost) on reproductive output, and 3) the effect of population density on reproductive output. The longevity of adult M. halterata increased under cooler temperatures and more humid conditions (>75% RH), which reflect the conditions inside mushroom-growing facilities. Similar numbers of flies emerged from freshly inoculated and 14-d spawned compost, but flies emerged earlier from 14-d spawned compost. The higher the parental fly density, the more offspring emerged from spawned compost, but the positive relationship reached a plateau beyond 40 parental mating pairs per 100 g of compost. Our findings highlight relevant abiotic and biotic factors that may contribute to M. halterata population dynamics.

Highbush blueberry is a crop native to the northeast USA that has been domesticated for about 100 years. This study compared the susceptibility of wild and domesticated/cultivated highbush blueberries to an invasive frugivorous pest, the spotted wing drosophila (Drosophila suzukii). We hypothesized that: 1) cultivated fruits are preferred by D. suzukii for oviposition and better hosts for its offspring than wild fruits; and, 2) wild and cultivated fruits differ in physico-chemical traits. Fruits from wild and cultivated blueberries were collected from June through August of 2015 and 2016 from 10 to 12 sites in New Jersey (USA); with each site having wild and cultivated blueberries growing in close proximity. The preference and performance of D. suzukii on wild and cultivated blueberries were studied in choice and no-choice bioassays. In addition, we compared size, firmness, acidity (pH), total soluble solids (°Brix), and nutrient, phenolic, and anthocyanin content between wild and cultivated berries. In choice and no-choice bioassays, more eggs were oviposited in, and more flies emerged from, cultivated than wild blueberries. Cultivated fruits were 2x bigger, 47% firmer, 14% less acidic, and had lower °Brix, phenolic, and anthocyanin amounts per mass than wild fruits. Levels of potassium and boron were higher in cultivated fruits, while calcium, magnesium, and copper were higher in wild fruits. These results show that domestication and/or agronomic practices have made blueberries more susceptible to D. suzukii, which was associated with several physico-chemical changes in fruits. Our study documents the positive effects of crop domestication/cultivation on an invasive insect pest.

The mushroom phorid fly, Megaselia halterata (Wood) (Diptera: Phoridae), is a key pest in mushroom farming in most parts of the world. Studies on the mushroom phorid fly have focused on its life history within mushroom growing houses, but little is known about the fly's activity outside mushroom growing houses. In this study, daily activity and distribution of adult M. halterata in the areas surrounding mushroom growing houses was studied using yellow sticky traps. Results suggest that M. halterata focuses its flight activity over turf areas rather than windbreaks and spent compost piles, possibly for mating purposes. Our study found no evidence of M. halterata breeding in turf areas surrounding mushroom growing houses. In addition, flight activity is highest in the afternoon until midnight at higher temperatures, yet at lower temperatures activity ceases after sunset. Establishing temperature and daylight thresholds for M. halterata flight activity may be useful in developing integrated pest management (IPM) tactics for this species. The most successful IPM tool that mushroom growers use at present is fly exclusion. Exclusion can be improved by focusing farm operations around temperature and daylight thresholds when fly activity is at its lowest.

Lycoriella ingenua Dufour (Diptera: Sciaridae) is a major pest species in commercial mushroom (Agaricus bisporus) production throughout the world. Grower demand for alternative control measures, following the recent withdrawal of a number of chemical control options, led to a label extension for use of the fungal biopesticide BotaniGard® ES, for control of mushroom flies. Semi-field trials were conducted to evaluate the efficacy of BotaniGard® ES, and two alternative formulations of Beauveria bassiana strain GHA (the active ingredient in BotaniGard® ES), for control of L. ingenua, and their effect on crop yield when incorporated at spawning. Data collected from two replicated trials demonstrated that incorporation of B. bassiana was not detrimental to mushroom yield, but was also ineffective in controlling the development of L. ingenua larvae in artificially infested compost. Subsequent laboratory bioassays demonstrated that L. ingenua eggs and larvae were not susceptible to infection by B. bassiana strain GHA whereas pupae were somewhat susceptible (41% mortality). Bioassays conducted on adult L. ingenua using 1 h exposure to a surface sprayed with BotaniGard® ES resulted in 100% mortality within 8 days and a mean survival time of 6 days, which was significantly different from the control population.

We deployed branch traps in an ash (Fraxinus) plantation to investigate how Agrilus planipennis behavior is associated with Fraxinus pennsylvanica condition and dispersal patterns. Data were collected from traps with or without the presence of beetle visual decoys, and from a yearly survey of exit holes. The traps were placed on trees that were either clearly declining, with most foliage arising from epicormic sprouting, or on apparently healthy trees, with little evidence of damage or decline. We calculated correlations of exit holes among neighboring tree rings and also between exit holes and male trap captures. The damaged trees the traps were hung upon had more cumulative exit holes observed than the corresponding healthy trees. However, there was otherwise no evidence that the experiment was biased by differences in exit hole patterns of the surrounding trees. Male captures were greater on decoy-baited traps than controls and this decoy effect was most clearly apparent late in the season when traps were placed on healthy trees. There were also patterns of correlations between male captures and exit hole numbers that may be indicative of short-range mate finding-and dispersal behaviors. Female captures were sparser, but were positively affected by decoys on healthy and declining trees early in the season. Thus, the results suggest that the placement of such traps on healthier trees will maximize detection, and the branch traps also show promise for further use in dispersal studies.

To evaluate the attractiveness of several mushroom-growing substrates to the female mushroom fly Lycoriella ingenua (Dufour) (Diptera: Sciaridae), a pest of the cultivated white button mushroom, Agaricus bisporus (JE Lange) Emil J Imbach (Agaricales), we developed a two-choice, static-flow olfactometer. Behavioral assays using this olfactometer indicated that mushroom compost with A. bisporus mycelia growing in it was not more attractive than compost lacking growing mycelia. We also found that female flies were more attracted to compost lacking A. bisporus mycelia than to the actual commodity, the white button mushroom fruiting bodies. Flies were not, however, attracted to sterilized compost, suggesting the attraction is due to volatiles produced by microbial metabolism in the compost. We also found that female L. ingenua flies were attracted to the mycoparasitic green mold Trichoderma aggressivum Samuels & W Gams (Hypocreales). Flies preferred mushroom compost that had T. aggressivum growing in it over compost lacking T. aggressivum, providing an experimental outcome consistent with the anecdotal belief that L. ingenua flies are vectors of T. aggressivum spores that can infest mushroom-growing houses.

The Streptomyces produce a great diversity of specialized metabolites, including highly volatile compounds with potential biological activities. Volatile organic compounds (VOCs) produced by nine Streptomyces spp., some of which are of industrial importance, were collected and identified using gas chromatography&ndash, mass spectrometry (GC-MS). Biosynthetic gene clusters (BGCs) present in the genomes of the respective Streptomyces spp. were also predicted to match them with the VOCs detected. Overall, 33 specific VOCs were identified, of which the production of 16 has not been previously reported in the Streptomyces. Among chemical classes, the most abundant VOCs were terpenes, which is consistent with predicted biosynthetic capabilities. In addition, 27 of the identified VOCs were plant-associated, demonstrating that some Streptomyces spp. can also produce such molecules. It is possible that some of the VOCs detected in the current study have roles in the interaction of Streptomyces with plants and other higher organisms, which might provide opportunities for their application in agriculture or industry.

Significant progress has been made in understanding the cues involved in the host and mate seeking behaviors of spotted wing drosophila, Drosophila suzukii (Matsumura). This insect pest has been discovered in many fruit growing regions around the world since 2008. Unlike closely related Drosophila species, D. suzukii attacks fresh fruit and has become a severe pest of soft fruits including strawberry, cherry, blackberry, blueberry, raspberry, and may pose a threat to grapes. Prior to 2008, little was known about the courtship and host-seeking behaviors or chemical ecology of this pest. Since then, researchers have gained a better understanding of D. suzukii attraction to specific odors from fermentation, yeast, fruit, and leaf sources, and the visual cues that elicit long-range attraction. Several compounds have also been identified that elicit aversive behaviors in adult D. suzukii flies. Progress has been made in identifying the constituent compounds from these odor sources that elicit D. suzukii antennal responses in electrophysiological assays. Commercial lures based on food volatiles have been developed to attract D. suzukii using these components and efforts have been made to improve trap designs for monitoring this pest under field conditions. However, current food-based lures and trap technologies are not expected to be specific to D. suzukii and thus capture large numbers of non-target drosophilids. Attractive and aversive compounds are being evaluated for monitoring, mass trapping, and for the development of attract-and-kill and push-pull techniques to manage D. suzukii populations. This review outlines presently available research on the chemical ecology of D. suzukii and discusses areas for future research.

There is growing evidence in the literature suggesting that caste differentiation in the stingless bee, Melipona scutellaris, and other bees in the genus Melipona, is triggered by environmental signals, particularly a primer pheromone. With the proper amount of food and a chemical stimulus, 25% of females emerge as queens, in agreement with a long-standing “two loci/two alleles model” proposed in the 1950s. We surmised that these larvae must be equipped with an olfactory system for reception of these chemical signals. Here we describe for the first time the diversity of antennal sensilla in adults and the morphology of larvae of M. scutellaris. Having found evidence for putative olfactory sensilla in larvae, we next asked whether olfactory proteins were expressed in larvae. Since the molecular basis of M. scutellaris is still unknown, we cloned olfactory genes encoding chemosensory proteins (CSP) and odorant-binding proteins (OBPs) using M. scutellaris cDNA template and primers designed on the basis CSPs and OBPs previously reported from the European honeybee, Apis mellifera. We cloned two CSP and two OBP genes and then attempted to express the proteins encoded by these genes. With a recombinant OBP, MscuOBP8, and a combinatorial single-chain variable fragment antibody library, we generated anti-MscuOBP8 monoclonal antibody. By immunohistochemistry we demonstrated that the anti-MscuOBP8 binds specifically to the MscuOBP8. Next, we found evidence that MscuOBP8 is expressed in M. scutellaris larvae and it is located in the mandibular region, thus further supporting the hypothesis of olfactory function in immature stages. Lastly, molecular modeling suggests that MscuOBP8 may function as a carrier of primer pheromones or other ligands.

We previously showed that the females of the mushroom sciarid, Lycoriella ingenua (Dufour, 1839) (Diptera: Sciaridae), one of the most severe pests of the cultivated white button mushroom, Agaricus bisporus (J.E. Lange) Emil J. Imbach (Agaricales: Agaricaceae), are attracted to the mushroom compost that mushrooms are grown on and not to the mushrooms themselves. We also showed that females are attracted to the parasitic green mold, Trichoderma aggressivum. In an attempt to identify what is in the mushroom compost that attracts female L. ingenua, we isolated several species of fungi from adult males and females, third instar larvae, and mushroom compost itself. We then analyzed the attraction of females to these substrates using a static-flow two choice olfactometer, as well as their oviposition tendencies in another type of assay under choice and no-choice conditions. We also assessed the survival of larvae to adulthood when first instar larvae were placed on each of the isolated fungal species. We found that female flies were attracted most to the mycoparasitic green mold, T. aggressivum, to Penicilium citrinum isolated from adult female bodies, and to Scatylidium thermophilium isolated from the mushroom compost. Gravid female flies laid the most eggs on T. aggressivum, Aspergillus flavus isolated from third instar larval frass, Aspergillus fumigatus isolated from adult male bodies, and on P. citrinum. This egg-laying trend remained consistent under no-choice conditions as females aged. First instar larvae developed to adulthood only on S. thermophilium and Chaetomium sp. isolated from mushroom compost, and on P. citrinum. Our results indicate that the volatiles from a suite of different fungal species act in tandem in the natural setting of mushroom compost, with some first attracting gravid female flies and then others causing them to oviposit. The ecological context of these findings is important for creating an optimal strategy for using possible semiochemicals isolated from these fungal species to better monitor and control this pestiferous mushroom fly species.

A three-step, quasi-double-bind approach was used as a proof-of-concept study to screen twenty compounds for their ability to reduce oviposition of gravid female navel orangeworm(NOW), Ameylois transitella (Lepidoptera: Pyralidae). First, the panel of compounds, whose identity was unknown to the experimenters, was tested by electroantennogram (EAG) using antennae of two-day old gravid females as the sensing element. Of the twenty compounds tested three showed significant EAG responses. These three EAG-active compounds and a negative control were then analyzed for their ability to reduce oviposition via small-cage, two-choice laboratory assays. Two of the three compounds significantly reduced oviposition under laboratory conditions. Lastly, these two compounds were deployed in a field setting in an organic almond orchard in Arbuckle, CA using black egg traps to monitor NOW oviposition. One of these two compounds significantly reduced oviposition on black egg traps under these field conditions. Compound 9 (later identified as isophorone) showed a significant reduction in oviposition in field assays and thus has a potential as a tool to control the navel orangeworm as a pest of almonds.