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Chitosan is a naturally derived polymer that has significant potential for use as a bioinsecticide. Despite this, there is a lack of research as to the efficacy of chitosan for many insect pest species. The apple maggot fly, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), is one such pest for which chitosan toxicity has not been explored. In this study, the toxicity of chitosan for R. pomonella adults was tested via no-choice feeding assays. An aging trial was further used to test the mortality of flies provided dried chitosan-sucrose treatments (CST), which were aged for 0 or 3 days in greenhouse conditions. This study found that the CST is toxic for R. pomonella adults when ingested, leading to a significant increase in the rate of mortality compared to control groups. The use of dried chitosan, however, did not change the mortality of flies, suggesting this will not be an effective delivery mechanism. Effective biopesticide delivery systems have not been defined for chitosan use outside of a laboratory, indicating the need for further research testing delivery mechanisms. It is suggested that an effective method of delivery can be as a food-based bait in attract-and-kill traps, as chitosan must be ingested to kill flies. Forming a viscous solution, chitosan may be best suited to these lure systems. [ABSTRACT FROM AUTHOR]

Native apple maggot fly, Rhagoletis pomonella , and invasive spotted-wing drosophila, Drosophila suzukii , are key pests of apple and small fruit, respectively, in the United States. Both species are typically managed with standard insecticide applications. However, interest in alternative strategies that result in insecticide reductions has led to evaluations of nonnutritive sugars as toxicants for Drosophila species and development of attracticidal spheres for both species. Here, we evaluated the survivorship of R. pomonella and D. suzukii when provided with standard diets that substituted saccharin, sucralose, aspartame, erythritol, dextrose, or mannitol for the sucrose component and compared them with standard diets and water-only controls for up to 15 days. Presence of erythritol and mannitol significantly decreased survivorship of R. pomonella and erythritol significantly decreased the survivorship of D. suzukii. However, mobility trials following a 2 h exposure to aqueous solutions of each sugar treatment resulted in no strong impact on either species. Survivorship after 30 min exposure to erythritol or mannitol alone, or in combination with varying concentrations of sucrose (serving as a phagostimulant) at 30 min and 24 h were evaluated for both species. Only D. suzukii survivorship was affected with decreased survivorship on erythritol:sucrose solutions of 20:0% and 15:5% for 24 h. Based on all results, erythritol appeared most promising, and was integrated into attracticidal spheres as a toxicant but even at the highest concentration, survivorship remained unaffected for either species, thus making this nonnutritive sugar impractical and ineffective as a toxicant substitute in attracticidal spheres. [ABSTRACT FROM AUTHOR]

Aphis spiraecola Patch is one of the most economically important tree fruit pests worldwide. The pyrethroid insecticide lambda-cyhalothrin is commonly used to control A. spiraecola. In this 2-year study, we quantified the resistance level of A. spiraecola to lambda-cyhalothrin in different regions of the Shaanxi province, China. The results showed that A. spiraecola had reached extremely high resistance levels with a 174-fold resistance ratio (RR) found in the Xunyi region. In addition, we compared the enzymatic activity and expression level of P450 genes among eight A. spiraecola populations. The P450 activity of A. spiraecola was significantly increased in five regions (Xunyi, Liquan, Fengxiang, Luochuan, and Xinping) compared to susceptible strain (SS). The expression levels of CYP6CY7 , CYP6CY14 , CYP6CY22, P4504C1-like , P4506a13 , CYP4CZ1 , CYP380C47, and CYP4CJ2 genes were significantly increased under lambda-cyhalothrin treatment and in the resistant field populations. A L1014F mutation in the sodium channel gene was found and the mutation rate was positively correlated with the LC50 of lambda-cyhalothrin. In conclusion, the levels of lambda-cyhalothrin resistance of A. spiraecola field populations were associated with P450s and L1014F mutations. Our combined findings provide evidence on the resistance mechanism of A. spiraecola to lambda-cyhalothrin and give a theoretical basis for rational and effective control of this pest species. [ABSTRACT FROM AUTHOR]

Simple Summary: In eastern North America, apple production faces threats from various moth species, particularly the codling moth (CM), Oriental fruit moth (OFM), redbanded leafroller (RBLR), obliquebanded leafroller (OBLR), and three-lined leafroller (TLLR) in the Tortricidae family. A study in Massachusetts orchards over two years examined the response of these moths to different lures, including commercial ones like Megalure. The results revealed Megalure's attractiveness to both sexes of the OFM and CM. The addition of benzaldehyde enhanced the capture of male OFMs, suggesting its potential to improve commercial lures with aromatic compounds. In eastern North America, apple orchards are often attacked by several species of tortricid moths (Lepidoptera), including Cydia pomonella, Grapholita molesta, Argyrotaenia velutinana, and Pandemis limitata. Sex pheromones are routinely used to monitor male moth populations. Adding plant volatiles to monitoring traps could increase the capture of moths of both sexes and improve the effectiveness of mating disruption systems. This study sought to quantify the attraction of adults of four tortricid moth species to five olfactory treatments, namely (1) Pherocon® CM L2-P, (2) Pherocon Megalure CM 4K Dual® (=Megalure), (3) Megalure + benzaldehyde, (4) TRE 2266 (linalool oxide + (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT)), and (5) TRE 2267 (linalool oxide + DMNT + benzaldehyde), in non-mating disrupted commercial apple orchards in Massachusetts. The commercial lure Megalure was attractive to both sexes of G. molesta and C. pomonella. The addition of benzaldehyde to TRE 2266 or to Megalure significantly increased the capture of male G. molesta during the mid and late season of 2021. Only when benzaldehyde was added to TRE 2266 did the latter lure attract P. limitata in 2020 and 2021. The greatest number of tortricid moths (all four species combined) was captured by TRE 2267. This finding highlights the opportunity to enhance the attractiveness of a commercial lure through the addition of benzaldehyde, an aromatic compound, to Megalure. The potential of these additional volatiles to detect moths in a mating-disrupted orchard and/or remove female moths as a component of a management system is discussed. [ABSTRACT FROM AUTHOR]

In commercial apple orchards, the odor-baited trap tree approach involving the synergistic lure composed of benzaldehyde (BEN) and the PC aggregation pheromone grandisoic acid (GA) serves as an effective monitoring tool as well as an attract-and-kill strategy for plum curculio (PC), Conotrachelus nenuphar Herbst. (Coleoptera: Curculionidae), management. However, the relatively high cost of the lure and the degradation of commercial BEN lures by UV light and heat discourage its adoption by growers. Over a 3-yr period, we compared the attractiveness of methyl salicylate (MeSA), either alone or in combination with GA, to plum curculio (PC) with that of the standard combination of BEN + GA. Our main goal was to identify a potential replacement for BEN. Treatment performance was quantified using 2 approaches: (i) unbaited black pyramid traps (2020, 2021) to capture PC adults and (ii) PC oviposition injury (2021, 2022) on apple fruitlets of trap trees and of neighboring trees to assess potential spillover effects. Traps baited with MeSA captured significantly more PCs than unbaited traps. Trap trees baited with a single MeSA lure and 1 GA dispenser attracted a similar number of PCs as trap trees baited with the standard lure composed of 4 BEN lures and 1 GA dispenser based on PC injury. Trap trees baited with MeSA + GA received significantly more PC fruit injury than neighboring trees suggesting no or limited spill-over effects. Our collective findings suggest that MeSA is a replacement for BEN thereby cutting costs of lures by ca. 50% while maintaining trap tree effectiveness. [ABSTRACT FROM AUTHOR]

Internal fruit borers (Lepidoptera: Tortricidae) are serious fruit pests. Of particular significance is Grapholita molesta given its pest status of stone and pome fruits. So far, successful control of tortricid moths largely relies on repeated insecticide applications. The development of novel technology by genome manipulation through CRISPR/Cas9 is an environmentally friendly pest management alternative. Due to the small size of eggs, CRISPR/Cas9 protocols have not been developed for tortricid moths like G. molesta. The white gene is widely used as genetic marker in Drosophila. Here, the white gene (Gmwhite) from G. molesta was identified and it was found that Gmwhite was expressed at all developmental stages. The Gmwhite knockout strain (White-KO) was established using CRISPR/Cas9 genome editing system. When compared with wild type, the eye color of the adult moth in the White-KO strain changed to white and the body color of the fifth-instar larvae of the White-KO strain changed from pink/red to white. The females' fecundity of the White-KO strain was not affected whereas the flight capacity was significantly decreased. The acquired white compound eye of the White-KO strain is autosomally recessive inherited. The feasibility of the CRISPR/Cas9 methodology was validated by dual-target editing of Gmwhite. Our findings provide the first evidence that the white gene can be used as a visual reference gene for genetic manipulation of tortricid moths. The present study developed CRISPR/Cas9-mediated gene editing technology which can be used for developing genome editing control strategy as well as for gene function analyses in G. molesta. [ABSTRACT FROM AUTHOR]

BACKGROUND: The peach fruit fly, Bactrocera zonata, and the Oriental fruit fly, B. dorsalis (Diptera: Tephritidae), are economically important fruit fly species in various regions of the world. We evaluated the effects of separate and combined applications of the entomopathogenic fungi (EPF) Beauveria bassiana (WG‐18) and Metarhizium anisopliae (WG‐02), and the entomopathogenic nematodes (EPNs) Heterorhabditis bacteriophora (VS strain) and Steinernema carpocapsae (ALL strain) against larvae, pupae and pharate adults, of B. zonata and B. dorsalis under laboratory, glasshouse and field cage conditions. RESULTS: Combined applications of EPF and EPNs produced greater mortality than individual treatments under all conditions. Against both species, the combination of B. bassiana and H. bacteriophora consistently exerted strong effects that were similar to the combined application of B. bassiana and S. carpocapsae whereas M. anisopliae applied with S. carpocapsae was least effective in all combinations. In a laboratory bioassay, synergistic interactions were detected between B. bassiana and H. bacteriophora applied against larvae and pharate adults of both fly species, between B. bassiana and S. carpocapsae against larvae of both species and pharate adults of B. zonata, and between M. anisopliae and H. bacteriophora against B. zonata larvae. Other combined treatments resulted in additive effects, especially against fly pupae. In a potted soil bioassay, there were only additive interactions in all combinations against different stages of both flies. The 3rd instar of both flies was more susceptible than pharate adult and pupal stages. Additive interactions between EPNs and EPF were detected in the glasshouse against 3rd instars and pupae, and under field conditions against 3rd instars of both fly species. CONCLUSION: These results indicate how particular combinations of entomopathogenic fungi and nematodes could be deployed in integrated pest management of tephritid fruit flies in orchard agro‐ecosystems. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: In recent years, there has been interest in low‐cost, reduced‐risk materials that could be used for attract‐and‐kill of the invasive pest, spotted‐wing Drosophila, Drosophila suzukii. This pest causes heavy economic damage to soft‐skinned fruits in many countries. In this study, we evaluated physiological and behavioral effects of adding either borax, boric acid, or sodium chloride to diluted Concord grape juice (DGJ), a material that is attractive to adult D. suzukii. RESULTS: Results showed that the addition of borax, sodium chloride and boric acid did not significantly affect the response of adult D. suzukii, relative to DGJ alone. Increases in concentrations (to 5% and 10%) of borax, sodium chloride and boric acid were correlated with decreased ingestion of materials. Mortality of males and females was almost 100% with lower concentrations (1% and 5%) of borax and boric acid within 72 h. The higher concentrations of sodium chloride (5% and 10%) resulted in 100% mortality of both sexes within 72 h. There was no significant effect of chemicals on the number of crop contractions of flies when fed for 4 h. CONCLUSIONS: This study suggests that some substances such as boric acid and borax may act as toxicants without influencing the behavioral response of D. suzukii. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Grapholita molesta is one of the most important fruit pests worldwide. Abamectin is a biological pesticide frequently used to control fruit borers like G. molesta in part owing to its translaminar properties. In this study, we characterized the toxicity of abamectin to G. molesta larvae using the diet incorporation method. The sublethal effects of abamectin on the development, reproduction, detoxification enzyme activity, and related gene expression of G. molesta were assessed. The results showed that the LC20 and LC50 values of the insecticide against G. molesta 72 h post-treatment were 1.17 mg L–1 and 5.85 mg L–1, whereas the LC20 and LC50 values 96 h post-treatment were 0.34 mg L–1 and 3.63 mg L–1. When compared to the control, sublethal concentrations of abamectin 1) significantly increased the mortality of the larvae, prepupae, and pupae of G. molesta , 2) prolonged the duration of 3rd to 5th instar larva, prepupal and pupal periods, 3) shortened the longevity of adults, and 4) reduced female fecundity. The enzymatic activity of glutathione S-transferase (GST) varied significantly after exposure to sublethal concentrations of abamectin, but the cytochrome P450 monooxygenases and carboxylesterase activity were not significantly affected. Thirteen of the 25 GST genes were significantly upregulated under different sublethal concentrations of abamectin. The combined findings increase our understanding of the effects of abamectin on G. molesta and the potential role of GSTs in the metabolic interactions of abamectin in this pest, and have applications for more rational and effective use of abamectin to control G. molesta. [ABSTRACT FROM AUTHOR]

[Display omitted] • We quantified attraction of Zeugodacus cucurbitae to induced host-plant volatiles. • Female age and type of olfactory cues influenced Zeugodacus cucurbitae behavior. • Induced volatiles involved in Zeugodacus cucurbitae attraction are short-lived. In many insect species including fruit flies (Diptera: Tephritidae), the behavioral responses to volatiles emitted by their host plants can be modulated by environmental conditions and by the physiological state of the insect. Here, we quantified (1) the effects of female age on the attraction of female melon fly, Zeugodacus cucurbitae (Diptera: Tephritidae) to volatiles emitted by intact and mechanically damaged tomato (Solanum lycopersicum), eggplant (S. melongena), zucchini (Cucurbita pepo), bitter melon (Momordica charantia), and cucumber (Cucumis sativus) fruit, and (2) the influence of time elapsed since fruit damage on the outcome. The investigations were conducted under semi-natural conditions in Hawai'i. Results from the first experiment revealed that, for freshly damaged tomato, eggplant, and zucchini, the level of female response was comparatively low and was not affected by female age. For bitter melon and cucumber, higher levels of response to freshly damaged fruit were documented, and the response levels gradually increased as female age increased from 1 to 4 weeks, reaching 70% for 4-week-old females exposed to cucumber odor. Results from our second experiment indicated that, on average, 56% of the females released responded in 20 min when cucumbers were freshly sliced, and the level of response was reduced 6-fold within a couple of hours. Females did not respond to tomato and cucumber odor when fruits were damaged >8 h before testing. Fruit volatiles involved in female Z. cucurbitae attraction seem to be released shortly upon mechanical damage and they are short-lived. The plasticity of the olfaction-driven behavior observed in Z. cucurbitae depending on female age and on the strength of the olfactory cues associated with preferred and less preferred hosts, adds another dimension to our understanding of the host-seeking behavior of this invasive species. [ABSTRACT FROM AUTHOR]

While trapping methods for Drosophila suzukii Matsumura (Diptera: Drosophilidae) have typically relied on fermentation volatiles alone or in association with a visual stimulus, the relative contribution of visual and olfactory stimuli to the food- and host-seeking behavior of D. suzukii is poorly understood. This study quantified the type of response exhibited by male and female D. suzukii to color and the effects that volatiles (fermentation, fresh fruit, and leaf) exert on the outcome. Seven-, four- and two-choice assays were used to quantify interactions between visual and olfactory cues. When no volatiles were present in a seven-choice assay, D. suzukii preferred red, black, and green pigments. Black and red were preferred when yeast odors were present, and black alone was the most attractive color when blueberry odor was present. A strawberry leaf terpenoid, β-cyclocitral, seemed to have overridden the flies' response to color. In four-choice assays, blueberry odor was more likely to interact synergistically with color than yeast or β-cyclocitral. This study demonstrates that D. suzukii modulates the response to multimodal sensory modalities (vision and olfaction) depending, to some extent, on the type of olfactory stimuli. Our findings also provide insight into the relative importance of vision as a function of odor quality in this invasive species. [ABSTRACT FROM AUTHOR]

The objectives of this study were to quantify the virulence of four entomopathogenic fungal species to pupae of Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) and to determine the potential to combine entomopathogenic fungi (EPFs) and entomopathogenic nematodes (EPNs) for biological control of this pest. The four species of EPFs included Beauveria bassiana (strain GHA), Metarhizium brunneum (strain F52), Isaria javanica (wf GA17), and Isaria fumosorosea (Apopka 97 strain). In laboratory assays, all fungi reduced adult emergence but there were no differences between fungal species. Isaria javanica and M. brunneum were examined further in a EPFs and EPNs bioassay that also included the EPNs Steinernema carpocapsae (ALL strain) and S. riobrave (355 strain). All nematodes and fungi were applied either alone or in combination (fungus + nematode). There were no differences between species within the same entomopathogen group (fungi and nematodes). However, the treatment with S. riobrave resulted in lower R. pomonella emergence than either fungal species. The combination of S. riobrave and I. javanica resulted in the lowest R. pomonella emergence (3%) at fourth-week interval, which was significantly lower than any of the single-agent applications, yet virulence of the other three combination treatments was not different from their respective nematode treatments applied alone. Additive interactions were detected for all fungus–nematode combinations. This study suggests that application of entomopathogenic nematodes and fungi could be an effective option to suppress R. pomonella populations. [ABSTRACT FROM AUTHOR]

Plants bearing extrafloral nectaries (EFNs) serve diverse ecological functions by providing nectar to a broad spectrum of arthropods (e.g., ants, parasitoids). This study examined the extent to which plant architecture of American elderberry (Sambucus canadensis L.; Sambucus nigra ssp. canadensis [L.] Bolli), resulting from two pruning methods that produced herbaceous (base-pruning) and woody (high-pruning) stems, and elderberry genotype (nine genotypes were evaluated) influenced ant attendance and arthropod abundance and diversity on elderberry EFNs. Results showed that the proportion of elderberry plants that produced EFNs was significantly greater for the base-pruning compared to the high-pruning method. The positive relationship found between the number of EFN-bearing plants that secreted nectar and ant attendance on EFNs was greater for the base-pruned plants compared to high-pruned plants. Plant genotype also significantly influenced the outcome. When base-pruned, the proportion of plants attended by ants was greatest for the genotypes Ocoee and Marge. The proportion of plants visited by other arthropods (e.g., parasitoids and predators) was greatest for the genotypes Ocoee, Bob Gordon, and Wyldewood. Overall, our findings indicate that the combination of plant genotype selection and selective pruning can modulate insect–plant interactions including mutualistic ant–elderberry associations and visitations by an array of arthropods. [ABSTRACT FROM AUTHOR]

Attraction of tephritid fruit flies to some food sources can be enhanced by the presence of ammonia derivatives, compounds that are perceived as volatile cues for protein‐rich food sources. Using a comparative approach, we (1) evaluated the behavioral responses of females of three invasive fruit fly species, Bactrocera (Zeugodacus) cucurbitae (Coquillett), Bactrocera dorsalis (Hendel), and Ceratitis capitata (Wiedemann) (all Diptera: Tephritidae) to trub (a protein‐rich waste brewer's yeast product generated during the production of beer), Concord grape juice (a protein‐deficient material), and ammonium acetate, and (2) identified synergistic and additive interactions between low‐ and high‐attractiveness materials and ammonium acetate. We established the attractiveness of fresh trub, grape juice, and ammonium acetate when tested singly to females of all three fly species. Although ammonium acetate did not enhance significantly the response of females of any species to fresh trub, the most attractive material, ammonium acetate, did significantly enhance females' level of response to aged trub (a comparatively less attractive material) and to grape juice. Our research found a synergistic interaction between diluted grape juice and ammonium acetate for B. cucurbitae, as well as between aged trub and ammonium acetate for B. dorsalis. For C. capitata, additive effects among food attractants and ammonium acetate were identified. Our findings increase our understanding of fruit fly female olfactory‐driven behavior in response to food‐based materials and the extent to which ammonium acetate modulates female response to protein‐rich and protein‐deficient materials. [ABSTRACT FROM AUTHOR]

In an attempt to utilize large amounts of Japanese beetles, Popillia japonica (Coleoptera: Scarabaeidae) that were captured using a mass trapping system, compost using Japanese beetle carcasses was prepared with the layer method. Carbon sources included shredded paper, wood chips and leaves, while the sole nitrogen source was frozen Japanese beetles. In addition, Japanese beetle-based vermicompost was prepared in the greenhouse by mixing the Japanese beetle-based compost with sphagnum peat moss and moist shredded paper and exposing this mixture to composting earthworms (Eisenia fetida). Chemical analyses of the Japanese beetle carcasses indicated that 10.8% of their body weight is nitrogen (N). Analyses of the resulting Japanese beetle-based compost and vermicompost indicated that both types of materials are good quality soil amendments. Greenhouse studies were conducted to quantify the effects of varying proportions of Japanese beetle-based vermicompost and compost mixed with a potting medium and varying dosages of synthetic fertilizer 20-0-0, on mean fresh and dry weight of lettuce shoots and leaf area. Japanese beetle-based compost and vermicompost increased lettuce biomass to an extent that was comparable with the addition of synthetic N-based fertilizer. A mixture of 15 and 30% of each compost type with potting media significantly increased plant weight and leaf area compared with potting medium alone. Results indicate that composting and vermicomposting insect carcasses are a simple, effective and affordable method to augment fertilization in support of organic production. [ABSTRACT FROM AUTHOR]

The spotted-wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), is attracted to numerous volatile organic compounds (VOCs) emitted from several ripening, small fruit crops. However, the strawberry leaf terpenoid, β-cyclocitral, is reportedly very attractive to D. suzukii (but not to all Drosophila spp.). This suggests that leaf and fruit VOCs may be critical sources needed to further develop a more species-specific D. suzukii monitoring lure, or semiochemically based attract-and-kill systems. This study investigated the electrophysiological responses of male and female D. suzukii towards selected host fruit-ripening VOCs and β-cyclocitral, along with behavioral responses toward combined fruit VOCs with β-cyclocitral. Electroantennogram (EAG) results revealed a positive dose–response, for both sexes, as concentrations increased for all VOCs tested. For β-cyclocitral, hexyl acetate and methyl butyrate, the mean male EAG responses were significantly greater than the female responses at lower doses. In caged behavioral bioassays, only in the β-cyclocitral treatments were the mean number of flies captured (sexes combined) significantly greater than that captured in solvent (mineral oil) controls. Our study has demonstrated that while single fruit-based VOCs alone are not enough to cause a strong behavioral attraction by both male and female D. suzukii , the addition of β-cyclocitral did produce a significant attraction response from both sexes. In both bioassays, males had higher responses to β-cyclocitral than females, which suggest a greater sensitivity to this compound. Further studies are needed to ascertain the role β-cyclocitral may play in the development of a more species-specific D. suzukii monitoring lure. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: In some regions of North America, damage caused by the Japanese beetle, Popillia japonica, has been increasing as beetle populations continue to become established and expand. This poses a pest management challenge for crop farmers, in particular organic producers. From 2014 to 2016 we evaluated the ability of novel mass trapping systems to capture P. japonica in elderberry and blueberry orchards in Missouri, USA. RESULTS: Across a 3‐year period in two locations, the mass trapping systems collected 10.3 million P. japonica adults while season‐long adult densities on crop plants were comparatively low (elderberry: 0.5–3.7 per plant; blueberry: 0.01–0.07 per plant). Damage by P. japonica averaged 6.8% per plant in elderberry and 0.12% in blueberry. In 2015 and 2016, large‐capacity bins with increased ventilation captured similar beetle numbers as did 1.2‐m‐long mesh socks (single design used in 2014), and these two trap designs outperformed non‐ventilated bins. CONCLUSION: The mass trapping designs captured high numbers of adult P. japonica, while comparatively few adults and little damage to the foliage were recorded on plants. Mass trapping may provide effective alternative management options for P. japonica with less or no insecticides applied to the crop. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Shortly after its introduction into the Hawaiian Islands around 1895, the polyphagous, invasive fruit fly Bactrocera (Zeugodacus) cucurbitae (Coquillett) (Diptera: Tephritidae) was provided the opportunity to expand its host range to include a novel host, papaya (Carica papaya). It has been documented that female B. cucurbitae rely strongly on vision to locate host fruit. Given that the papaya fruit is visually conspicuous in the papaya agro-ecosystem, we hypothesized that female B. cucurbitae used vision as the main sensory modality to find and exploit the novel host fruit. Using a comparative approach that involved a series of studies under natural and semi-natural conditions in Hawaii, we assessed the ability of female B. cucurbitae to locate and oviposit in papaya fruit using the sensory modalities of olfaction and vision alone and also in combination. The results of these studies demonstrate that, under a variety of conditions, volatiles emitted by the novel host do not positively stimulate the behavior of the herbivore. Rather, vision seems to be the main mechanism driving the exploitation of the novel host. Volatiles emitted by the novel host papaya fruit did not contribute in any way to the visual response of females. Our findings highlight the remarkable role of vision in the host-location process of B. cucurbitae and provide empirical evidence for this sensory modality as a potential mechanism involved in host range expansion. [ABSTRACT FROM AUTHOR]

Fruit flies (Diptera: Tephritidae) are among the most economically important pest species in the world, attacking a wide range of fruits and fleshy vegetables throughout tropical and sub-tropical areas. These species are such devastating crop pests that major control and eradication programs have been developed in various parts of the world to combat them. The array of control methods includes insecticide sprays to foliage and soil, bait-sprays, male annihilation techniques, releases of sterilized flies and parasitoids, and cultural controls. During the twenty first century there has been a trend to move away from control with organophosphate insecticides (e.g., malathion, diazinon, and naled) and towards reduced risk insecticide treatments. In this article we present an overview of 73 pest species in the genus Bactrocera, examine recent developments of reduced risk technologies for their control and explore Integrated Pest Management (IPM) Programs that integrate multiple components to manage these pests in tropical and sub-tropical areas. [ABSTRACT FROM AUTHOR]

Ammonia and its derivatives are used by female fruit flies (Diptera: Tephritidae) as volatile cues to locate protein-rich food needed to produce their eggs. This need for external protein sources has led to the development of behaviorally based control strategies such as food-based lures and insecticidal baits targeting pestiferous fruit fly species. In field cage studies conducted in Hawaii, we examined the behavioral response of laboratory-reared male and female Mediterranean fruit fly, Ceratitis capitata (Wiedemann), to seven commercially available protein baits and to beer waste, a relatively inexpensive and readily available substance. Each material was tested alone or in combination with either ammonium acetate or ammonium carbonate. For the majority of baits evaluated, the presence of ammonium acetate, but not ammonium carbonate, elicited a significantly greater level of response of female C. capitata compared with the protein baits alone. The addition of ammonium acetate to selected baits increased bait attractiveness to a level comparable with that elicited by the most widely used spinosad-based protein bait, GF-120. Our findings indicate that the addition of ammonium acetate to commercially available proteinaceous baits and to beer waste can greatly improve their attractiveness to C. capitata, potentially increasing the bait's effectiveness for fruit fly monitoring and suppression. [ABSTRACT FROM AUTHOR]

Key to the effectiveness of fruit fly (Diptera: Tephritidae) suppression efforts using insecticidal bait sprays is the determination of how long the bait remains attractive to adult flies after application. Using a comparative approach, field studies were conducted in commercial papaya (Carica papaya L.; Brassicales: Caricaceae) orchards in Hawaii with the goal of quantifying the response of Bactrocera dorsalis (Hendel) and Bactrocera cucurbitae (Coquillett) wild females to yellow bait stations treated with 2 dilutions (40% and 20%) of GF-120 NF Naturalyte™ Fruit Fly Bait that had been aged either outdoors (for 3 and 7 days) or indoors (for 1, 2, 3, and 7 days). Important variations in the level of female response to the baits were documented between these 2 fruit fly species, and the response levels were modulated by bait dilution, duration of aging and aging conditions. For B. dorsalis wild females, the attractiveness of 40% GF-120 and aged outdoors for either, 3 or 7 days did not differ significantly from the fresh bait, whereas for B. cucurbitae wild females a significant reduction (48 %) in bait attractiveness was recorded within 1 day of aging indoors independent of percent dilution of the bait. Environmental conditions, in particular mean temperature and relative humidity, prevailing during bait aging outdoors differed significantly from those recorded indoors, and these differences appeared to have influenced the attractiveness of GF-120. The types of variations in the level of responses to the aged baits documented in this study between fruit fly species within a genus, and potentially across genera need to be considered when developing suppression programs for fruit flies that involve the use of bait sprays. [ABSTRACT FROM AUTHOR]

The apple maggot fly, Rhagoletis pomonella (Walsh), is a key pest of apple in eastern North America that has been historically controlled with organophosphate insecticide applications. Here we report on progress toward development of an effective and maintenance-free attracticidal sphere system for this pest species. In our studies, we evaluated lethality of spinosad in combination with a feeding stimulant (sucrose) to replace a Tangletrap sticky coating as the killing agent of a sphere-based behavioral control system. Spinosad was incorporated into cylindrical and contoured controlled-release caps that were fixed atop visually stimulating sphere bases. For both cap styles, spinosad at or near 1.0% (a.i.) proved to be a relatively durable fly-killing agent, providing ≈85% mortality after simulated rainfall exposure reflective of average season-long precipitation levels experienced during the primary period of risk of apple maggot injury to fruit in the northeastern United States. In field trials, we assessed the impact of color degradation of contoured controlled-release caps on visual responsiveness of apple maggot fly and found that it had no significant impact on captures. In commercial orchard trials designed to evaluate the potential of attracticidal spheres with contoured caps for direct control of apple maggot, a perimeter-based deployment provided protection comparable to plots receiving 1-2 whole-plot insecticide applications. [ABSTRACT FROM AUTHOR]

The article focuses on a study which described the morphological features of the ovaries during previtellogenesis through vitellogenesis and ovulation of the Oriental fruit fly Bactrocera dorsalis. The morphological features were assessed as markers of the physiological states of the oriental fruit fly. Study authors described the morphometrics of ovarian development in female Bactrocera dorsalis, and noted that morphometry of the ovary increased significantly between each oogenesis stage.

The effectiveness of foliar applications of protein baits against pestiferous fruit flies (Tephritidae) can be adversely affected by a rapid loss of attractive volatile compounds and by rainfall due to the high water solubility of the baits. In a large coffee, Coffea arabica L., plantation in Hawaii with high and low populations of Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), the relative attractiveness of GF-120 NF Naturalyte Fruit Fly Bait as either a 40% (vol:vol) spray solution (=GF-120 NF) or as a formulated proprietary amorphous polymer matrix (=GF-120 APM) was compared. The GF-120 APM formulations contained either, 25, 50, or 75% of GF-120 NF (wt:wt). All baits were tested in association with visually attractive yellow bait stations as a way of standardizing the evaluations. With both high and low C. capitata populations, significantly more females were attracted to the fresh sprayed GF-120 NF than to any of the three fresh GF-120 APM formulations. The attractiveness of GF-120 sprayed decreased significantly after 1 wk, whereas 1-wk-old GF-120 APM formulations were as attractive as similar fresh formulations. GF-120 APM 75% aged for 3 wk outperformed similarly-aged sprayed GF-120 NF with comparatively high C. capitata populations. With low populations, both GF-120 APM 75% and GF-120 APM 50% aged for 2 wk outperformed the similarly aged sprayed GF-120 NF. Combined findings indicate that APM mixed with either 50 or 75% GF-120 applied to bait stations can be attractive to female C. capitata for up to 3 wk longer than the standard sprayed GF-120 NF. [ABSTRACT FROM AUTHOR]

The plum curculio, Conotrachelus nenuphar (Herbst), is a key pest of pome and stone fruit in eastern and central North America. For effective management of this insect pest in commercial apple (Malus spp.) orchards in the northeastern United States and Canada, one of the greatest challenges has been to determine the need for and timing of insecticide applications that will protect apple fruit from injury by adults. In a 2004-2005 study, we assessed the efficacy and economic viability of a reduced-risk integrated pest management strategy involving an odor-baited trap tree approach to determine need for and timing of insecticide use against plum curculio based on appearance of fresh egg-laying scars. Evaluations took place in commercial apple orchards in seven northeastern U.S. states. More specifically, we compared the trap-tree approach with three calendar-driven whole-block sprays and with heat-unit accumulation models that predict how long insecticide should be applied to orchard trees to prevent injury by plum curculio late in the season. Trap tree plots received a whole-plot insecticide spray by the time of petal fall, and succeeding sprays (if needed) were applied to peripheral-row trees only, depending on a threshold of one fresh plum curculio egg-laying scar out of 25 fruit sampled from a single trap tree. In both years, level of plum curculio injury to fruit sampled from perimeter-row, the most interior-row trees and whole-plot injury in trap tree plots did not differ significantly from that recorded in plots subject to conventional management or in plots managed using the heat-unit accumulation approach. The amount of insecticide used in trap tree plots was reduced at least by 43% compared with plots managed with the conventional approach. Advantages and potential pitfalls of the bio-based trap tree approach to plum curculio monitoring in apple orchards are discussed. [ABSTRACT FROM AUTHOR]

The article discusses a study concerning the treatments for the suppression of Mediterranean fruit fly, Ceratitis capitata and the oriental fruit fly, Bactrocera dorsalis in Kamuela, Hawaii. It is stated that sanitation, Naturalyte Fruit Fly Bait Sprays, male annihilation, Biolure traps and parasitoids were used for the suppression of both fruit flies. It further states that the release of sterile males against B. dorsalis was also effective in reducing fruit infestation levels.

The article discusses a study demonstrating the efficacy of rain fast bait station over foliar sprays in reducing the population of female oriental fruit fly, Bactrocera dorsalis. It is stated that the incidence of infestation in papaya orchards was also studied which demonstrates the reduction in the rate of infestation to 45.4 percent in 12 weeks. It further states that the use of bait stations is far more economical and safer than foliar sprays.

Worldwide, an important aspect of invasive insect pest management is more effective, safer detection and control systems. Phenyl propanoids are attractive to numerous species of Dacinae fruit flies. Methyl eugenol (ME) (4-allyl-1, 2-dimethoxybenzene-carboxylate), cue-lure (C-L) (4-(p-acetoxyphenyl)-2-butanone), and raspberry ketone (RK) (4-(p-hydroxyphenyl)-2-butanone) are powerful male-specific lures. Most evidence suggests a role of ME and C-L/RK in pheromone synthesis and mate attraction. ME and C-L/RK are used in current fruit fly programs for detection, monitoring, and control. During the Hawaii Area-Wide Pest Management Program in the interest of worker safety and convenience, liquid C-L/ME and insecticide (i.e., naled and malathion) mixtures were replaced with solid lures and insecticides. Similarly, Male Annihilation Technique (MAT) with a sprayable Specialized Pheromone and Lure Application Technology (SPLAT), in combination with ME (against Bactrocera dorsalis, oriental fruit fly) or C-L/RK (against B. cucurbitae, melon fly), and the reduced-risk insecticide, spinosad, was developed for area-wide suppression of fruit flies. The nontarget effects of ME and C-L/RK to native invertebrates were examined. Although weak attractiveness was recorded to flower-visiting insects, including bees and syrphid flies, by ME, effects to native Drosophila and other Hawaiian endemics were found to be minimal. These results suggested that the majority of previously published records, including those of endemic Drosophilidae, were actually for attraction to dead flies inside fruit fly traps. Endemic insect attraction was not an issue with C-L/RK, because B. cucurbitae were rarely found in endemic environments. [ABSTRACT FROM AUTHOR]

Methyl eugenol (ME) and cue-lure (C-L) traps with solid lure dispensers were deployed in areas with low and high populations of oriental fruit fly, Bactrocera dorsalis (Hendel), and melon fly, Bactrocera cucurbitae (Coquillett),respectively. In low-density areas, standard Jackson traps or Hawaii Fruit Fly Areawide Pest Management (AWPM) traps with FT Mallet ME wafers impregnated with dimethyl dichloro-vinyl phosphate (DDVP) or AWPM traps with Scentry ME cones and vapor tape performed equally as well as standard Jackson traps with liquid ME/C-L and naled. Standard Jackson traps or AWPM traps with FT Mallet C-L wafers impregnated with DDVP or AWPM traps with Scentry C-L plugs with vapor tape performed equally as well as standard Jackson traps with a lure-naled solution. In high density areas, captures with traps containing FT Mallet wafers (ME and C-L) outperformed AWPM traps with Scentry cones and plugs (ME and C-L) with DDVP insecticidal strips over a 6-mo period. Captures of B. dorsalis and B. cucurbitae with wafers containing both ME and raspberry ketone (FT Mallet MC) were equivalent to those containing separate lures. From a worker safety and convenience standpoint, FT Mallet ME and C-L wafers with DDVP or Scentry plugs, with or without DDVP vapor tape, are more convenient and safer to handle than standard liquid insecticide formulations used for monitoring and male annihilation programs in Hawaii, and for detections traps used on the U.S. mainland. Furthermore, the FT Mallet MC wafer might be used in a single trap in place of two separate traps for detection of both ME and C-L responding fruit flies. [ABSTRACT FROM AUTHOR]

A novel, visually-attractive bait station was developed in Hawaii for application of insecticidal baits against oriental fruit fly, Bactrocera dorsalis (Hendel), melon fly, Bactrocera cucurbitae (Coquillett), and Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (all Diptera: Tephritidae). The bait station developed represents a supernormal visual stimulus of papaya foliage and takes advantage of the flies’ strong response to the high light-reflecting properties of yellow color and of their need for shelter, while fully protecting the bait against rainfall. Field studies revealed that the behavioral response of female fruit flies, in particular C. capitata and B. cucurbitae, to yellow-painted bait stations sprayed with GF-120 NF Naturalyte Fruit Fly Bait was significantly enhanced compared with similarly sprayed bait stations that mimicked the green color of fully grown papaya leaves. Field studies conducted with B. cucurbitae indicated that the period of bait attractiveness can be extended for at least 1 week after bait application due to the rain-fastness properties of the bait stations and the use of a visually-attractive color. Our studies provide the behavioral basis for the development of improved attract-and-kill bait stations for fruit flies in Hawaii. These devices also provide a standardized way of evaluating bait spray formulations, thus allowing for proper comparisons over time, across species, and among geographical areas. [ABSTRACT FROM AUTHOR]

Studies were conducted in 2007 and 2008 in Hawaii, USA to quantify attraction and feeding responses resulting in mortality of the male oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), to a novel male annihilation treatment (MAT) formulation consisting of specialized pheromone and lure application technology (SPLAT) in combination with methyl eugenol (ME) and spinosad (=SPLAT-MAT-ME with spinosad) in comparison with Min-U-Gel-ME with naled (Dibrom). Our approach involved a novel behavioral methodology for evaluation of slow-acting reduced-risk insecticides. Methyl eugenol treatments were weathered for 1, 2, 4, and 8 weeks in California, USA, and shipped to Hawaii for bioassays. In field tests involving bucket traps to attract and capture wild males, and in toxicity studies conducted in 1 m3 cages using released males of controlled ages, SPLAT-MAT-ME with spinosad performed similar to or outperformed the standard formulation of Min-U-Gel-ME with naled for material aged for up to 8 weeks in the 2008 tests. In laboratory feeding tests in which individual males were exposed for 5 min to the different ME treatments, mortality induced by SPLAT-MAT-ME with spinosad recorded at 24 h did not differ from that caused by Min-U-Gel ME with naled at 1, 2, and 4 weeks. Spinosad has low contact toxicity, and when mixed with SPLAT offers a reduced-risk alternative for control of B. dorsalis, without many of the negative effects to humans and non-targets of broad-spectrum contact poisons such as naled. Our results indicate that SPLAT-MAT-ME with spinosad offers potential for control of males in an area-wide integrated pest management (IPM) system without the need for conventional organophosphates. [ABSTRACT FROM AUTHOR]

The efficacy of GF-120 NF Naturalyte Fruit Fly Bait in combination with field sanitation was assessed as a control for female oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in papaya (Carica papaya L.) orchards in Hawaii. Three different bait spray regimes were evaluated: every row (high use of the bait), every fifth row (moderate use), and every 10th row (low use). Orchard plots in which no bait was applied served as controls. For five of the seven biweekly periods that followed the first bait spray, trapping data revealed significantly fewer female B. dorsalis captured in plots subject to high and moderate bait use than in control plots. Differences in incidence of infestation among treatments were detected only by the third (12 wk after first spray) fruit sampling with significantly fewer infested one-fourth to one-half ripe papaya fruit in plots subject to high and moderate bait use than in control plots. Parasitism rates by Fopius arisanu.s (Sonan) (Hymenoptera: Braconidae) were not negatively affected by bait application. Results indicate that foliar applications of GF-120 NF Naturalyte Fruit Fly Bait either to all rows (every other tree),or to every fifth row (every tree) in combination with good sanitation can effectively reduce infestation by B. dorsalis in papaya orchards in Hawaii. [ABSTRACT FROM AUTHOR]

The attractiveness of peach ( Prunus persica L. Batsch) and apple ( Malus domestica L. Borkh.) (both Rosaceae) tissue to gravid female oriental fruit moth, Grapholita (=  Cydia) molesta (Busck) (Lepidoptera: Tortricidae), was assessed at three distinct stages throughout the growing season using a dual-choice bioassay. Plant material offered to the female moths consisted of a plant shoot in early spring, before fruit became available. Later, it consisted of a leaf-bearing twig and a fruit, either alone or in combination. The level of attraction of the female moths to the various plant tissues varied substantially over time and according to the plant species. Before fruit became available, female moths were significantly attracted to peach as well as to apple shoots. During the early fruit growth stage, moths were attracted to a leaf-bearing twig originating from a peach tree, but not to that from an apple tree. In peach, it was the vegetative tissue that accounted for the attraction, whereas in apple, it was the reproductive tissue (a developing fruit). During the late fruit growth stage, both peach fruit and apple fruit were highly attractive, whereas a twig with leaves from either an apple or a peach tree was neither attractive nor repellent to the female moths. This changing female olfactory response to volatiles emitted by vegetative tissue and fruits from the two host plant species with progressing season is discussed with respect to the biology and the dispersal of this moth species. [ABSTRACT FROM AUTHOR]

Methyl eugenol (ME) and cue-lure (C-L) traps to detect tephritid flies on the U.S. mainland were tested with and without insecticides under Hawaiian weather conditions against small populations of oriental fruit fly, Bactrocera dorsali.s (Hendel) and melon fly, Bactrocera cucurbitae (Coquillett), respectively. In comparative tests, standard Jackson traps with naled and the Hawaii fruit fly areawide pest management (AWPM) trap with 2,2-dichorovinyl dimethyl phosphate (DDVP) insecticidal strips outperformed traps without an insecticide. Addition of the reduced risk insecticide spinosad did not increase trap capture significantly compared with Jackson traps without an insecticide. Captures in AWPM traps with DDVP compared favorably with those for the Jackson trap with liquid naled (the Florida standard). In subsequent tests, captures with solid Farma Tech wafer dispensers with ME or C-L and DDVP placed inside Jackson and AWPM traps were equal to those for a Jackson trap with naled, currently used for detection of ME and C-L responding fruit flies in Florida, Farma Tech ME and C-L wafers with DDVP would be more convenient and safer to handle than current liquid insecticide formulations (e.g., naled) used for detection programs in Florida. [ABSTRACT FROM AUTHOR]

The plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae), one of the most important pests of apple (Mains spp.) in eastern and central North America, historically has been managed in New England apple orchards by three full block insecticide applications. Efforts to reduce insecticide inputs against plum curculio include perimeter row sprays, particularly after petal fall, to control immigrating adults. The odor-baited trap tree approach represents a new reduced input strategy for managing plum curculio based on the application of insecticides to a few perimeter-row trap trees rather than the entire perimeter row or hill orchard block. Here, we compared the efficacy of a trap tree approach with perimeter row treatments to manage populations after petal fall in commercial apple orchards in 2005 and 2006. Injury was significantly greater in trap trees compared with unbaited perimeter row treated trees in both years of the study. In 2005, heavy rains prevented growers from applying insecticide applications at regular intervals resulting in high injury in nearly all blocks regardless of type of management strategy. In 2006, both the trap-tree and perimeter-row treatments prevented penetration by immigrating populations and resulted in economically acceptable levels of injury. The trap tree management strategy resulted in a reduction of ≈70% total trees being treated with insecticide compared with perimeter row sprays and 93% compared with standard full block sprays. [ABSTRACT FROM AUTHOR]

Specialized Pheromone and Lure Application Technology (SPLAT) methyl eugenol (ME) and cue-lure (C-L) "attract-and-kill" sprayable formulations containing spinosad were compared with other formulations under Hawaiian weather conditions against oriental fruit fly, Bactrocera dorsalis (Hendel), and melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), respectively, Field tests were conducted with three different dispensers (Min-U-Gel, Acti-Gel, and SPLAT) and two different insecticides (naled and spinosad). SPLAT ME with spinosad was equal in performance to the standard Min-U-Gel ME with naled formulation up to 12 wk. SPLAT C-L with spinosad was equal in performance to the standard Min-U-Gel C-L with naled formulation during weeks 7 to 12, but not during weeks 1-6. In subsequent comparative trials, SPLAT ME + spinosad compared favorably with the current standard of Min-U-Gel ME + naled for up to 6 wk, and it was superior from weeks 7 to 12 in two separate tests conducted in a papaya (Carica papaya L.) orchard and a guava (Psidium guajava L.) orchard, respectively. In outdoor paired weathering tests (fresh versus weathered), C-L dispensers (SPLAT + spinosad, SPLAT + naled, and Min-U-Gel + naled) were effective up to 70 d. Weathered ME dispensers with SPLAT + spinosad compared favorably with SPLAT + naled and Min-U-Gel + naled, and they were equal to fresh dispensers for 21-28 d, depending on location. Our current studies indicate that SPLAT ME and SPLAT C-L sprayable attract-and-kill dispensers containing spinosad are a promising substitute for current liquid organophosphate insecticide formulations used for areawide suppression of B. dorsalis and B. cucurbitae in Hawaii. [ABSTRACT FROM AUTHOR]