The miR-31b targets arylsulfatase B to regulate the ovarian development of Bactrocera dorsalis.

BACKGROUND: Reproduction is the basis of insect population growth and evolution, and encompasses ovarian development, reproductive behavior, and fecundity. Bactrocera dorsalis is a globally significant agricultural pest that is subject to quarantine, with mated females that can lay over 3000 eggs. The post-transcriptional regulation of ovarian development remains unclear. Here, miR-31b is shown to be involved in regulating Bactrocera dorsalis ovarian development. RESULTS: CRISPR/Cas9 was used to generate miR-31b loss-of-function mutations in Bactrocera dorsalis. The removal of miR-31b resulted in severely impaired ovarian development in adults, with phenotypes that included dramatically reduced egg production and hatching rates. The relationship between miR-31b and its target gene arylsulfatase B (ARSB) was subsequently identified using the methods of bioinformatics, transcriptomic sequencing, quantitative polymerase chain reaction (qPCR), RNA pull-down and dual-luciferase reporter assay. Finally, miR-31b was confirmed to bind the target gene arylsulfatase B to affect metabolism and thereby further hindered ovarian development of Bactrocera dorsalis. CONCLUSION: Overall, these results provide new insights into molecular mechanisms at the post-transcriptional level in regulating ovarian development and insect reproduction, consequently providing potential targets to control arthropod pests through the reproductive strategy. © 2024 Society of Chemical Industry.

Attractant potential of Enterobacter cloacae and its metabolites to Bactrocera dorsalis (Hendel).

Objective: Bactrocera dorsalis (Hendel) has a wide host range. It has been the most important quarantine pest in many countries or regions. Currently, chemical control and bait trapping are mainly used in the monitoring, prevention, and control of B. dorsalis. However, chemical control will cause pollution of the environment and drug resistance of insects. Methyl eugenol, the main attractant currently used, can only attract males of B. dorsalis. Methods: This study focused on the attractant function and active substances of one key intestinal bacterium, Enterobacter cloacae, which was isolated from B. dorsalis. Results: First, the attraction of the E. cloacae autoclaved supernatant to male and female adults of 0, 6, and 15 days post-emergence was confirmed using a Y-type olfactometer. Subsequently, through metabolome sequencing and bioassays, L-prolinamide was identified and confirmed as the most effective attractant for B. dorsalis. Finally, the synergistic effect of L-prolinamide with the sex attractant ME was validated through field experiments. This study confirmed the attraction effect of E. cloacae on B. dorsalis and also proved the attraction effect of L-prolinamide, the metabolite of E. cloacae, on B. dorsalis. This laid a theoretical foundation for the development of a new attractant and safe, green, and efficient prevention and control technology of B. dorsalis.

Lure Monitoring for Mediterranean Fruit Fly Traps Using Air Quality Sensors.

Effective pest population monitoring is crucial in precision agriculture, which integrates various technologies and data analysis techniques for enhanced decision-making. This study introduces a novel approach for monitoring lures in traps targeting the Mediterranean fruit fly, utilizing air quality sensors to detect total volatile organic compounds (TVOC) and equivalent carbon dioxide (eCO2). Our results indicate that air quality sensors, specifically the SGP30 and ENS160 models, can reliably detect the presence of lures, reducing the need for frequent physical trap inspections and associated maintenance costs. The ENS160 sensor demonstrated superior performance, with stable detection capabilities at a predefined distance from the lure, suggesting its potential for integration into smart trap designs. This is the first study to apply TVOC and eCO2 sensors in this context, paving the way for more efficient and cost-effective pest monitoring solutions in smart agriculture environments.

The genome sequence of a tephritid fruit fly, Merzomyia westermanni Meigen 1826.

We present a genome assembly from an individual Merzomyia westermanni (a tephritid fruit fly; Arthropoda; Insecta; Diptera; Tephritidae). The genome sequence spans 986.20 megabases. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 19.45 kilobases in length. Gene annotation of this assembly on Ensembl identified 25,765 protein-coding genes.

Electroantennographic and behavioral responses of Bactorcera dorsalis (Diptera: Tephritidae) adults to the volatiles of plum fruits.

Fruit volatiles play a crucial role in the host localization by the oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae). This study focused on identifying the fruit volatiles from Sanyue plum and Sanhua plum (Prunus salicina Lindl.), which are 2 varieties of the same species, and examined their impact on the behavior of B. dorsalis by using a Y-olfactometer. A total of 35 and 54 volatiles from Sanyue plum and Sanhua plum were identified, respectively. Among these, 23 volatiles elicited electroantennographic (EAG) responses by B. dorsalis adults, showing concentration-dependent effects in males and females. Ethyl butyrate, butyl acetate, butyl hexanoate, ethyl caproate, ethyl hexanoate, and hexyl acetate significantly attracted B. dorsalis compared to liquid paraffin, while nonaldehyde was avoided. There was no significant difference in the behavioral responses of both sexes to sorbitol esters, hexyl isobutyrate, and 1-tetradecene compared with the control liquid paraffin group. Interestingly, (3Z)-C-3-hexenyl acetate significantly attracted females, but not males. The above findings suggest that plum fruit volatiles are likely to facilitate the localization of host fruit by B. dorsalis adults and may even aid in mate-finding. This study opens up new avenues for exploring novel plant-based attractants that might be of value for the integrated management of B. dorsalis.

The genome sequence of the Hawthorn Fruit Fly, Anomoia purmunda (Harris, 1780).

We present a genome assembly from a female Hawthorn Fruit Fly, Anomoia purmunda (Arthropoda; Insecta; Diptera; Tephritidae). The genome sequence has a length of 798.30 megabases. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 16.48 kilobases in length.

Chromosome-scale genome of the polyphagous pest Anastrepha ludens (Diptera: Tephritidae) provides insights on sex chromosome evolution in Anastrepha.

The Mexican fruit fly, Anastrepha ludens, is a polyphagous true fruit fly (Diptera: Tephritidae) considered one of the most serious insect pests in Central and North America to various economically relevant fruits. Despite its agricultural relevance, a high-quality genome assembly has not been reported. Here, we described the generation of a chromosome-level genome for the A. ludens using a combination of PacBio high fidelity long-reads and chromatin conformation capture sequencing data. The final assembly consisted of 140 scaffolds (821 Mb, N50 = 131 Mb), containing 99.27% complete conserved orthologs (BUSCO) for Diptera. We identified the sex chromosomes using three strategies: 1) visual inspection of Hi-C contact map and coverage analysis using the HiFi reads, 2) synteny with Drosophila melanogaster, and 3) the difference in the average read depth of autosomal versus sex chromosomal scaffolds. The X chromosome was found in one major scaffold (100 Mb) and eight smaller contigs (1.8 Mb), and the Y chromosome was recovered in one large scaffold (6.1 Mb) and 35 smaller contigs (4.3 Mb). Sex chromosomes and autosomes showed considerable differences of transposable elements and gene content. Moreover, evolutionary rates of orthologs of A. ludens and Anastrepha obliqua revealed a faster evolution of X-linked, compared to autosome-linked, genes, consistent with the faster-X effect, leading us to new insights on the evolution of sex chromosomes in this diverse group of flies. This genome assembly provides a valuable resource for future evolutionary, genetic, and genomic translational research supporting the management of this important agricultural pest.

Differential water deprivation tolerances of adult Rhagoletis indifferens and Rhagoletis pomonella (Diptera: Tephritidae) as a possible factor affecting their distributional abundances in Washington State, USA.

Insects that evolved in mesic regions may have difficulty establishing in xeric regions. Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) was introduced into drier western North America from mesic eastern North America while Rhagoletis indifferens Curran is native to western North America. Here, we predicted that R. indifferens survives water deprivation longer than R. pomonella, as R. indifferens is more abundant than R. pomonella in dry central Washington (WA) State, USA. Sweet and bitter cherry-origin R. indifferens and apple- and hawthorn-origin R. pomonella from xeric central or mesic western WA were provided water throughout or were water-deprived at 2-4 and 14-18 d old and held at 20°C or 30/31°C and daily survival recorded. At 20°C and 30°C, western WA apple-origin R. pomonella provided water survived longer than sweet cherry-origin R. indifferens. When water-deprived, however, 2-4 d old R. indifferens, although smaller, survived significantly longer than western WA apple-origin R. pomonella of the same age. This was also generally true for 14-18 d old flies, although differences were less often significant. Central WA large-thorn hawthorn-origin R. pomonella survived water deprivation significantly longer than western WA apple-origin R. pomonella, and as long as R. indifferens. Water-deprived flies of both species survived longer at 20°C than 30/31°C. Survival analyses suggest that low water availability rather than high temperature contributes to lower R. pomonella than R. indifferens abundances in central WA, with R. pomonella populations in that region differing from western WA R. pomonella with respect to tolerance of xeric climates.

Kukoamine A alleviates nephrolithiasis by inhibiting endogenous oxalate synthesis via the IL-6/JAK/STAT3/DAO signaling pathway.

BACKGROUND: The recurrent nature and socioeconomic burden of nephrolithiasis demand effective treatments. Delineating the crosstalk between inflammatory processes and the endogenous oxalate metabolism pathway, which underpins nephrolithiasis pathogenesis, is essential for advancing treatment strategies. PURPOSE: We aim to screen therapeutic Chinese herbal remedies and their bioactive constituents for kidney stone treatment using a fruit fly model, followed by efficacy and mechanism validation in a rodent nephrolithiasis model as well as in vitro human cell culture model. STUDY DESIGN AND METHODS: We developed a fruit fly model to screen for efficient traditional Chinese medicine herbs and their active compounds for kidney stone treatment. Candidate active compounds from efficient herbs were separated and identified by solid-phase chromatography coupled with LC-MS analysis. Fruit fly genetic tools were employed to manipulate the expression of related genes to explore the therapeutic mechanisms of the Lycii Cortex and kukoamine A (KuA). To confirm the therapeutic effects and mechanisms of KuA for mammalian nephrolithiasis, mouse model of glyoxylate-induced kidney stone and human renal tubular cells were used. The therapeutic role of kukoamine A in nephrolithiasis was evaluated by assessing tubular injury, crystal deposition, and adhesion. The level of expression and phosphorylation in cells and mice was assessed using RT-qPCR and western blot. RESULTS: Our findings indicate that Lycii Cortex potently inhibits calcium oxalate stone formation via activation of the JNK/Upd3/JAK/STAT signaling cascade, resulting in diminished endogenous oxalate synthesis by downregulating D-amino acid oxidase (DAO) gene expression, predominantly in fruit fly Malpighian tube stellate cells. KuA was identified as the principal bioactive constituent mediating these effects. Both mouse models and human cell assays confirmed KuA's efficacy in preventing calcium oxalate nephrolithiasis in mammals, through hepatic JAK/STAT3 pathway activation and upregulation of IL-6, culminating in reduced urinary crystal deposition. CONCLUSION: Our research underscores the potential of kukoamine A as a lead compound in treating nephrolithiasis and reveals the interplay between the IL-6/JAK/STAT3 inflammatory pathway and endogenous oxalate metabolism in nephrolithiasis pathogenesis. Additionally, it highlights the utility of the fruit fly model as a powerful tool for deciphering the therapeutic mechanisms of traditional Chinese herbs.

Divergent Heat Stress Responses in Bactrocera tryoni and Ceratitis capitata.

Invasive Tephritid fruit flies rank among the most destructive agricultural and horticultural pests worldwide. Heat treatment is commonly employed as a post-harvest method to exterminate fruit flies in fruits or vegetables. These pest species exhibit distinct tolerance to heat treatments, suggesting that the molecular pathways affected by heat may differ among species. In this study, the Queensland fruit fly (Qfly), Bactrocera tryoni, was utilised as a model investigate its molecular response to heat stress through heat bioassays. RNA samples from flies before and after heat treatment were extracted and sequenced to identify genes with significant changes in expression. These findings were compared to another serious Tephritid fruit fly species, the Mediterranean fruit fly (Medfly), Ceratitis capitata, under similar heat treatment conditions. The analysis reveals only three common genes: heat shock protein 70 (HSP70), HSP68, and 14-3-3 zeta protein. However, despite these shared genes, their expression patterns differ between Qfly and Medfly. This suggests that these genes might play different roles in the heat responses of each species and could be regulated differently. This study presents the first evidence of differing molecular responses to heat between Qfly and Medfly, potentially linked to their varied origins, habitats, and genetic backgrounds. These findings offer new insights into Tephritid fruit fly responses to heat at the molecular level, which may help refine post-harvest strategies to control these pests in the future.

Classification, biology and entomopathogenic fungi-based management and their mode of action against Drosophila species (Diptera: Drosophilidae): a review.

This review provides a comprehensive analysis of the classification, biology, and management of Drosophila species (Diptera: Drosophilidae) with a focus on entomopathogenic fungi (EPF) as a biocontrol strategy. Drosophila species, particularly Drosophila suzukii, and Drosophila melanogaster have emerged as significant pests in various agricultural systems, causing extensive damage to fruit crops. Understanding their taxonomic classification and biological traits is crucial for developing effective management strategies. This review delves into the life cycle, behavior, and ecological interactions of Drosophila species, highlighting the challenges posed by their rapid reproduction and adaptability. The review further explores the potential of EPF as an eco-friendly alternative to chemical pesticides. The mode of action of EPF against Drosophila species is examined, including spore adhesion, germination, and penetration of the insect cuticle, leading to host death. Factors influencing the efficacy of EPF, such as environmental conditions, fungal virulence, and host specificity, are discussed in detail. By synthesizing current research, this review aims to provide valuable insights into the application of EPF and to identify future research directions for enhancing the effectiveness of EPF-based control measures against Drosophila species.

The gustatory receptor BdorGr43a mediated sucrose preference in the feeding of Bactrocera dorsalis.

The feeding behavior of animals is pivotal for their reproductive success and energy acquisition. In our study, we found that the Bactrocera dorsalis had a pronounced preference for sucrose among six plant-derived sugars during feeding. Then, we searched the entire genome of B. dorsalis for the gustatory receptors (Grs) responsible for sucrose sensation. Putative gustatory receptors involved in the detection of sweetness, bitterness, CO2 and other unknown functions. Together with phylogenetic analysis, expression profiling, calcium imaging, and CRISPR/Cas9 mediated mutagenesis, we found that BdorGr43a is the key receptor responding to sucrose. Our study elucidated the molecular mechanism underlying the sucrose preferences in the feeding of B. dorsalis. Meanwhile, our results will serve as a reference for the understanding of gustatory sensing in insect. Furthermore, BdorGr43a may serve as an important target for the development of food attractants against the oriental fruit fly.

The effects of diet and semiochemical exposure on male Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) metabolic rate at a range of temperatures.

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an invasive species that has rapidly spread across the African continent, endangering the security of agricultural industries. The sterile insect technique (SIT) is being investigated as a viable additional pest management tool to suppress B. dorsalis populations after its successful implementation in other parts of the world. There is evidence to suggest that pre-release nutritional and semiochemical treatments for sterilised males can enhance their competitive performance against wild type males in SIT programs. This study examined how sterilisation, a diet rich in protein (addition of yeast hydrolysate) or containing semiochemicals (methyl eugenol or eugenol) affected the resting metabolic (RMR) of male B. dorsalis at different temperatures (15 - 30 °C), measured using flow-through respirometry. Our results indicated that the negative effect of sterilisation on RMR decreased as temperature increased and that duration of exposure to semiochemicals for 1 to 4 days was not a significant influencing factor on male B. dorsalis RMR. Protein-rich diet increased average RMR, but the difference in RMR between dietary groups decreased as temperature increased. Semiochemical feeding reduced the average RMR in male B. dorsalis. The difference in RMR between males that consumed semiochemical and those that did not increased with as temperature increased.

Ionotropic Receptor 8a (Ir8a) Plays an Important Role in Acetic Acid Perception in the Oriental Fruit Fly, Bactrocera dorsalis.

Bactrocera dorsalis is one of the major invasive pests worldwide. The acetic acid-enriched sweet bait trapping is an important method for monitoring and controlling this fly. Several studies showed that acetic acid is perceived by ionotropic receptors (IRs). Thus, we annotated 65 IR genes in the B. dorsalis genome. We also investigated the IRs involved in acetic acid perception in this fly by behavioral, electrophysiological, and molecular methods. As the results indicated, the antennae are the main olfactory organs to sense acetic acid. Among the antennal IRs showed acetic acid-induced expression profiles, IR8a was proven to perceive acetic acid by CRISPR/Cas9-mediated mutagenesis. Additionally, calcium imaging showed that IR64a and IR75a are potential acetic acid receptors respectively co-expressed with IR76b and IR8a. This study represents the first comprehensive characterization of IRs in B. dorsalis at the whole-genome level, revealing the significant role of IRs in acetic acid perception.

Phytosanitary cold treatment of cherry tomatoes infested with Bactrocera dorsalis, Zeugodacus cucurbitae, and Zeugodacus tau (Diptera: Tephritidae).

Fruit flies attack numerous crops, including cherry tomatoes (Solanum lycopersicum var. cerasiforme). The potential presence of the immature stages of fruit fly species inside tomatoes during export hinders their international market access. Therefore, phytosanitary treatment must be performed before export to prevent fruit fly species from entering countries where they are not naturally found. We developed a phytosanitary cold disinfestation treatment protocol to eliminate oriental fruit fly (Bactrocera dorsalis Hendel), melon fly (Zeugodacus cucurbitae Coquillett), and pumpkin fruit fly (Zeugodacus tau Walker) concealed inside cherry tomatoes without causing critical damage to the fruit. We determined that the third instar of Z. cucurbitae exhibited the highest cold tolerance among the various development stages of the three fruit fly species. Thus, we performed a small-scale disinfestation test on Z. cucurbitae in two cultivars of tomato. We achieved complete disinfestation after 15 days of cold treatment at 1°C-1.5°C. The confirmatory test revealed the elimination of more than 80,000 treated third instar of Z. cucurbitae in each tomato variety. The developed phytosanitary cold treatment allows the tomatoes to retain their commercial value. This study provides a standard phytosanitary cold treatment protocol for cherry tomatoes, ensuring the disinfestation of fruit flies before their export to international markets.

Spatially Varying Wolbachia Frequencies Reveal the Invasion Origin of an Agricultural Pest Recently Introduced From Europe to North America.

The introduction of non-native species across the world represents a major global challenge. Retracing invasion origin is an important first step in understanding the invasion process, often requiring detailed sampling within the native range. Insect species frequently host Wolbachia, a widespread endosymbiotic bacterium that manipulates host reproduction to increase infected female fitness. Here, we draw on the spatial variation in infection frequencies of an actively spreading Wolbachia strain wCer2 to investigate the invasion origin of the European cherry fruit fly, Rhagoletis cerasi. This pest of cherries was introduced from Europe to North America within the last decade. First, we screen the introduced fly population for the presence of Wolbachia. The introduced populations lack the wCer2 strain and the strongly associated mitochondrial haplotype, suggesting strain absence due to founder effects with invading individuals originating from wCer2-uninfected native population(s). To narrow down geographic regions of invasion origin, we perform spatial interpolation of the wCer2 infection frequency across the native range and predict the infection frequency in unsampled regions. For this, we use an extensive dataset of R. cerasi infection covering 238 populations across Europe over 25 years, complemented with 14 additional populations analyzed for this study. We find that R. cerasi was unlikely introduced from wCer2-infected populations in Central and Western Europe. We propose wCer2-uninfected populations from Eastern Europe and the Mediterranean region as the most likely candidates for the invasion origin. This work utilizes Wolbachia as an indirect instrument to provide insights into the invasion source of R. cerasi in North America, revealing yet another application for this multifaceted heritable endosymbiont. Given the prevalence of biological invasions, rapidly uncovering invasion origins gives fundamental insights into how invasive species adapt to new environments.

Longitudinal activity monitoring and lifespan: quantifying the interface.

Understanding the relationship between activity over the entire lifespan and longevity is an important facet of aging research. We present a comprehensive framework for the statistical analysis of longitudinal activity and behavioral monitoring and their relationship with age-at-death at the individual level, highlighting the importance of advanced methodological approaches in aging research. The focus is on animal models, where continuous monitoring activity in terms of movement, reproduction and behaviors over the entire lifespan is feasible at the individual level. We specifically demonstrate the methodology with data on activity monitoring for Mediterranean fruit flies. Advanced statistical methodologies to explore the interface between activity and age-at-death include functional principal component analysis, concurrent regression, Fréchet regression and point processes. While the focus of this perspective is on relating age-at-death with data on movement, reproduction, behavior and nutrition of Mediterranean fruit flies, the methodology equally pertains to data from other species, including human data.

A fruit fly-based approach to unraveling enteropathy-causing pharmaceuticals.

Enteropathy is a gastrointestinal disorder characterized by inflammation in the small intestine and one of the causes of enteropathy is the side effects of certain drugs, such as non-steroidal anti-inflammatory drugs (NSAIDs). The mechanism of NSAIDs, such as indomethacin, could inhibit prostaglandin synthesis, leading to a decrease in mucus production and small intestine integrity. To test the effects of a drug, it is necessary to undergo preclinical testing using animal models. Commonly used animal models such as mice and rats have several drawbacks including high cost, ethical issues, and long lifespan. Therefore, alternatives such as using invertebrate animals like Drosophila melanogaster as a more economical in vivo platform with genetic similarity to mammals and devoid of ethical concerns are needed. The aim of this study was to evaluate Drosophila melanogaster as an in vivo model organism in testing the side effects of pharmaceuticals that cause enteropathy. In this study, flies aged 3-5 days were starved and then placed into treatment vials comprising untreated control and indomethacin-treated (3.75 mM, 7.5 mM, and 15 mM). Survival analysis was conducted during the treatment period, followed by a Smurf assay test after seven days of treatment. Subsequently, the expression of pro-inflammatory cytokine-related genes (drs and totA), mitochondria stability-related genes (tom40), and endogenous antioxidant-related genes (sod1, sod2, and cat) was performed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Our data indicated that indomethacin did not impact lifespan or cause intestinal damage. However, we observed increased expression of pro-inflammatory cytokine-related genes, including drs, and a twofold increase in totA gene expression. Furthermore, there was a significant upregulation of mitochondrial stability gene tom40, endogenous antioxidant genes sod1 and cat, and a threefold increase in sod2 at 15 mM indomethacin. Although no phenotypical changes in gut integrity were detected, the increased expression of pro-inflammatory cytokine genes suggests the occurrence of inflammation in the indomethacin-treated flies.

The genome sequence of a drosophilid fruit fly, Drosophila limbata von Roser 1840.

We present a genome assembly from an individual male Drosophila limbata (drosophilid fruit fly; Arthropoda; Insecta; Diptera; Drosophilidae). The genome sequence is 233.5 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 16.09 kilobases in length.

Attractiveness, longevity, and release rates of multilure wafers for trapping males of the oriental fruit fly and melon fly (Diptera: Tephritidae).

Invasive fruit flies (Diptera: Tephritidae) pose a serious threat to the production and export of many commercially important fruits and vegetables. Detection of the agricultural pests Bactrocera dorsalis (Hendel) and Zeugodacus cucurbitae (Coquillett) relies heavily on traps baited with male-specific attractants. For B. dorsalis, traps are typically baited with liquid methyl eugenol (ME), and for Z. cucurbitae, traps are baited with liquid cue-lure (CL). Operating large-scale trapping networks is costly, consequently, there is much interest in identifying ways to maintain network sensitivity while reducing costs. One cost-cutting approach is the possibility of combining different male lures in the same dispenser, thus reducing the number of traps requiring servicing. The chief objective of this study was to compare captures of B. dorsalis and Z. cucurbitae males in Jackson traps baited with polymeric wafers impregnated with both ME and raspberry ketone (RK, a hydrolyzed form of CL) versus traps baited with liquid ME or CL freshly applied to cotton wicks. Captures were measured when the ME/RK wafers had been weathered for 12, 18, or 24 wk. Captures of B. dorsalis and Z. cucurbitae males were similar between fresh lure and weathered wafers over all trapping periods, with a single exception apparently due to the lessened potency of the associated killing agent. The residual amount and release rate of ME and RK from the wafers were also measured to examine possible relationships between wafer chemistry and trap catch. The possible implications of the present results to area-wide trapping programs are discussed.