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The pumpkin fruit fly, Bactrocera tau (Walker) (Diptera: Tephritidae) is one of the most serious insect pests of fruits, vegetables and nuts over the world due to its polyphagous nature and high reproductive rate. To gain insight into their sensory system, the external morphology, typology, density, and distribution of sensilla on full bodies of both adult male and female B. tau were observed using a scanning electron microscope. The observed sensilla showed organ as well as sex specific differences. Seven previously described sensilla (two non-olfactory, five olfactory with 17 subtypes) and a new sensillum named as "branched sensilla" (two subtypes) were identified and observed on the different body parts. Olfactory sensilla named as sensilla trichodea and sensilla basiconica were reported on the compound eyes for the first time. Majority of the olfactory sensilla were reported on the head appendages. The presence of species-specific as well as sex-specific branched sensilla in females showed different typology patterns of sensilla. The potential roles of observed sensilla were hypothesized through comparative analysis with prior research. The current findings can provide a reference for understanding the diversity of various olfactory and non-olfactory sensilla in B. tau as well as sex-specific morphological differences and functions of various body parts; thereby, aiding in the development of precise methods for regulating and managing insect behaviour. [ABSTRACT FROM AUTHOR]

Insects rely on odorant receptors (ORs) to detect and respond to volatile environmental cues, so the ORs are attracting increasing interest as potential targets for pest control. However, experimental analysis of their structures and functions faces significant challenges. Computational methods such as template-based modeling (TBM) and AlphaFold3 (AF3) could facilitate the structural characterisation of ORs. This study first showed that both models accurately predicted the structural fold of MhOR5, a jumping bristletail OR with known experimental 3D structures, although accuracy was higher in the extracellular region of the protein and binding mode of their cognate ligands with TBM. The two approaches were then compared for their ability to predict the empirical binding evidence available for OR-odorant complexes in two economically important fruit fly species, Bactrocera dorsalis and B. minax. Post-simulation analyses including binding affinities, complex and ligand stability and receptor-ligand interactions (RLIs) revealed that TBM performed better than AF3 in discriminating between binder and non-binder complexes. TBM's superior performance is attributed to hydrophobicity-based helix-wise multiple sequence alignment (MSA) between available insect OR templates and the ORs for which the binding data were generated. This MSA identified conserved residues and motifs which could be used as anchor points for refining the alignments. [ABSTRACT FROM AUTHOR]

Biotic and abiotic factors influence how insects respond to stimuli. This can make it challenging to interpret captures in traps used to monitor pest abundance in management programmes. To address this, the lure response of three pest fruit flies (Diptera: Tephritidae) was evaluated in a semi-field setting with respect to several physiological and environmental factors. Using standardised methods with known fly numbers in field cages, the response to Biolure (food-based lure) was evaluated for Ceratitis capitata, Ceratitis cosyra and Bactrocera dorsalis. Response to the male lures was tested: E.G.O PheroLure for C. capitata and C. cosyra, Trimedlure for C. capitata, and methyl eugenol for B. dorsalis. The physiological variables evaluated were fly age, sex, weight, and total body nutritional composition. The environmental effects of temperature, relative humidity and light intensity were also assessed. Protein-deprived adults responded more strongly to Biolure. The response to Biolure was not sex-specific. Fly age influenced the response of all species to all tested lures. However, this effect was species and lure specific. Temperature was the most influential environmental factor, with response generally increasing with temperature. Lower thresholds for lure response, despite the proximity of responsive flies, range from 12.21 to 22.95 °C depending on the species and lure tested. These results indicate that trapping systems and management activity thresholds must take physiological and environmental variation into account to increase their accuracy. [ABSTRACT FROM AUTHOR]

BACKGROUND: Insecticide resistance among invasive tephritid fruit flies poses a great risk to national food security and has the potential to disrupt quarantine and eradication programs, which rely on the efficacy of Spinosad to prevent widespread establishment in North America. During 2022 to 2023 we surveyed the extent of Spinosad resistance of two key species, oriental fruit fly Bactrocera dorsalis, and melon fly Zeugodacus cucurbitae, from 20 sites across five Hawaiian Islands including Kaua'i, O'ahu, Maui, Molokai and the "Big Island" (Hawai'i). RESULTS: We used topical thoracic applications of eight concentrations of Spinosad ranging from 0.028 to 3.6 mg/mL to evaluate the lethal concentration (LC50 and LC99) required to kill wild‐caught males. Resistance ratios (RR) were calculated by comparing the LC50 of wild flies to laboratory susceptible lines maintained in colony. Our results identified at least two new sites of concern for melon fly resistance on the Big Island, and at least four sites of concern for oriental fruit fly, all of which were located on the Big Island. At these locations RRs were >5. On O'ahu, melon fly RRs were >10. CONCLUSIONS: The persistence of Spinosad resistance is concerning, yet it is a reduction compared to the values reported previously and before changes to Spinosad use recommendations by local extension agents beginning in 2017. For oriental fruit fly, these RR values are the highest levels that have been detected in wild Hawai'i populations. These data suggest that expanded Spinosad reduction and replacement programs are warranted given the ongoing issues with Spinosad resistance in Hawai'i and expansion in the number of species affected. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. [ABSTRACT FROM AUTHOR]

Simple Summary: Fruit flies are major pests that cause extensive damage to fruits and vegetables worldwide. Understanding how these insects respond to heat treatment is crucial for developing effective methods to control them. In this study, we investigated how the Queensland fruit fly and the Mediterranean fruit fly react at a molecular level when exposed to heat. We found that each species responds differently, activating different genes to cope with the stress. By identifying the specific genes involved, we can design targeted heat treatments that are more effective for each species. This tailored approach can improve the efficiency of pest control, reduce the need for harmful chemicals, and minimise damage to the environment. Our findings offer valuable insights for developing better strategies to manage fruit fly populations, ensuring healthier crops and reducing economic losses for farmers. This research highlights the importance of understanding species-specific responses to stress and provides a foundation for future studies aimed at optimising pest management techniques. 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. [ABSTRACT FROM AUTHOR]

Copyright of Indonesian Journal of Agricultural Sciences / Jurnal Ilmu Pertanian Indonesia is the property of IPB University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Insects rely on odorant receptors (ORs) to detect and respond to volatile environmental cues, so the ORs are attracting increasing interest as potential targets for pest control. However, experimental analysis of their structures and functions faces significant challenges. Computational methods such as template-based modeling (TBM) and AlphaFold3 (AF3) could facilitate the structural characterisation of ORs. This study first showed that both models accurately predicted the structural fold of MhOR5, a jumping bristletail OR with known experimental 3D structures, although accuracy was higher in the extracellular region of the protein and binding mode of their cognate ligands with TBM. The two approaches were then compared for their ability to predict the empirical binding evidence available for OR-odorant complexes in two economically important fruit fly species, Bactrocera dorsalis and B. minax. Post-simulation analyses including binding affinities, complex and ligand stability and receptor-ligand interactions (RLIs) revealed that TBM performed better than AF3 in discriminating between binder and non-binder complexes. TBM’s superior performance is attributed to hydrophobicity-based helix-wise multiple sequence alignment (MSA) between available insect OR templates and the ORs for which the binding data were generated. This MSA identified conserved residues and motifs which could be used as anchor points for refining the alignments.

Identification of fruit flies and the methods of their control are essential to overcome the problem of pests. Using attractants is one of the control methods, which is environmental friendly and leaves no residue on plants. The study aimed to identify the species of fruit flies attacking Siam citrus plants and determine the most effective type of attractants to control their population. Identification was made on the fruit flies captured on attractants, and the study on attractants was conducted using a Randomized Block Design (RBD) consisting of four treatments and five replications. Four treatments (type of attractants) were petrogenol, rongit glue, chery glue, and king super glue. Two species of fruit flies, i.e., Bactrocera dorsalis and B. umbrosa, were found in the citrus plantation in Lambung Bukik Padang. The most effective attractants to control the fruit fly population were rongit glue and super king glue, which trapped the highest number of flies. Rongit glue trapped on the average of 94.2 individuals, and King superglue at 91.0 individuals per week. Rongit glue and super king glue can reduce fruit fly attacks. It is also part of an integrated pest management system to support sustainable agriculture.

The peach fruit fly (PFF), Bactrocera zonata (Saunders, 1841) (Diptera: Tephritidae) is a destructive polyphagous pest infesting a lot of horticultural fruits and some vegetables. At Damietta governorate, Egypt, the present study aimed to maximize the efficiency of the male annihilation technique (MAT) by estimating different types of blocks (as dispensers) impregnated with different doses (3, 6, and 9 cm³/block) of methyl eugenol to attract PFF males in guava orchards. Two different types of blocks [Hard woodpulpluff (HWF) and plant fibers] were selected for the present study. These blocks were tested as uncovered blocks and covered with aluminum polyethylene polyester. The study was carried out over eight successive weeks (from 27th September to 15th November 2023). The obtained results showed that the covered HWF blocks impregnated with the dose of 9 cm³/block were superior in attracting PFF males all over the investigation period followed by uncovered plant fibers, uncovered HWF, and covered plant fibers' blocks. There were positive relationships between the captured PFF males and the concentration of methyl eugenol. The covered HWF blocks were relatively more stable against elapsed time in comparison with uncovered HWF or plant fibers' blocks. In conclusion, the covered HWF blocks were more effective dispensers all over eight weeks for methyl eugenol to attract PFF males in comparison with uncovered HWF blocks and plant fibers. [ABSTRACT FROM AUTHOR]

The solanum fruit fly Bactrocera latifrons (Diptera: Tephritidae) is an invasive alien insect that causes huge economic losses to pepper and other solanaceous plant industries. It is mainly distributed in South and Southeast Asia, SW Europe, Western USA, and in some African countries. However, the potential global geographical distribution of B. latifrons is unknown. Therefore, in this study, based on the current (1981–2010) and future (2040–2059) climatic scenarios determined using the CNRM-CM5, Access1.0, GFDL-ESM-2M, and NorESM1-M models, we used a species distribution model (CLIMEX 4.0) to project the potential global geographic distribution of B. latifrons to prevent further invasion and harm. In the current climate scenario, South America (1286.06 × 104 km2), Africa (1435.47 × 104 km2), and Oceania (410.66 × 104 km2) have the largest proportions of suitable land areas for B. latifrons colonization. Under all four future climate models, the global potential suitable area for Bactrocera latifrons is projected to decrease and shift towards higher latitudes. This study provides an important baseline upon which researchers, quarantine personnel, and governments can develop the appropriate control strategies against B. latifrons. [ABSTRACT FROM AUTHOR]

Numerous insects are attracted to low levels of ammonia, utilizing it as a cue to locate food sources. The Ammonium Transporter (Amt), a highly conserved, atypical olfactory receptor, has been shown to mediate the detection of ammonia in insects. While the attraction of Tephritidae to ammonia is well established, knowledge about the Amt in this family is limited. The species Bactrocera dorsalis (Hendel 1912), Bactrocera cucurbitae (Coquillett 1899), Bactrocera correcta Bezzi 1916 and Bactrocera tau (Walker 1849), which are common agricultural pests within Tephritidae, exhibit numerous ecological similarities, offering a solid foundation for studying Amt characteristics in this family. In this study, we elucidated the sequences, evolutionary relationships, and expression patterns of Amt in these four species. The results indicated that these Amts share the same open reading frame, containing 1770 bp that encode a protein of 589 amino acid residues. These Amt proteins exhibit the typical structural characteristics of Amts, including an 11-transmembrane domain with an extracellular N-terminus and an intracellular C-terminus. They also have the ability to form trimers in the membrane. Additionally, they contain three conserved amino acid residues essential for ammonia transport: A189, H195, and H352. Phylogenetic and expression pattern analyses showed that they are highly conserved in Diptera and are significantly expressed in antennae. This study is the first report characterizing the Amt gene in four Tephritidae species. These findings provide a foundation for further exploration into the roles of these genes in their particular biological contexts. [ABSTRACT FROM AUTHOR]

Phytophagous insects differ in their degree of specialization to their host plants. It ranges from monophagous or oligophagous species that can only develop on a single host plant, or family of host plants, to extremely polyphagous species that can develop on plants from many distinct botanical families. The aim of this study was to compare the larval performance and adult preference of a highly generalist species, the Queensland fruit fly (Bactrocera tryoni) and a highly specialist species, the breadfruit fruit fly (B. umbrosa) among several fruits covering both species' host range. (i) larval performance was tested on 16 fruit species, and (ii) a female preference was tested on a subset of five fruit species. In addition, (iii) a field survey was carried out on 11 fruit species. B. umbrosa infested only Artocarpus fruits in the field. Accordingly, B. umbrosa larvae survived and developed only on fruits belonging to the Artocarpus genus. Female B. umbrosa did not lay their eggs on non‐Artocarpus fruits, except Terminalia catappa. Female B. tryoni, on the other hand, made little selection between the fruits tested, and its larvae developed on 13 of the 16 fruit species tested. The larval performance of both species, adjusted when tested by female preference, predicted in large part the fruit infestation in the field. These data are essential to better estimate invasion risk where the species are not established. [ABSTRACT FROM AUTHOR]

The study aimed to explore the variety of fruit flies present in mango orchards across different agro-ecological zones within the Saharanpur district of Uttar Pradesh, India. Fruit fly samples were gathered from 12 locations spanning 5 agro-ecological zones using methyl eugenol baited traps during the mango fruity season (Apr-Oct) of the year 2022 in Saharanpur. A total of eight species of genus Bactrocera were found infesting mango orchards in study regions. Out of a total collection from each zone, Bactrocera zonata emerged as the predominant species with total number recorded 3750, followed by Bactrocera dorsalis (3022, B. correcta (1375) and B. tau (1245). B. tuberculata and B. nigrotibalis exhibited low abundance across all locations. The diversity indices, as measured by Shannon's index, was highest in Behat, followed by Nakur. Simpson's reciprocal index indicated higher values at Behat and Nakur, suggesting higher diversity in the fruit fly population. Also, Behat and Nakur showed more species richness than others. We also studied the influence of different weather parameter on the population dynamics and observed a significant positive correlation between fruit fly population and the temperature whileas there is a negative correlation with average rainfall and humidity. [ABSTRACT FROM AUTHOR]

Bactrocera tryoni and Bactrocera neohumeralis are morphologically similar sibling pest fruit fly species that possess different biological attributes, geographic distributions, and host ranges. The need to differentiate between the two species is critical for accurate pest status assessment, management, biosecurity, and maintenance of reference colonies. While morphologically similar, adults may be separated based on subtle characters; however, some characters exhibit intraspecific variability, creating overlap between the two species. Additionally, there is currently no single molecular marker or rapid diagnostic assay that can reliably distinguish between B. neohumeralis and B. tryoni; therefore, ambiguous samples remain undiagnosed. Here we report the first molecular marker that can consistently distinguish between B. tryoni and B. neohumeralis. Our diagnostic region consists of two adjacent single nucleotide polymorphisms (SNPs) within the pangolin (pan) gene region. We confirmed the genotypes of each species are consistent across their distributional range, then developed a tetra‐primer amplification refractory mutation system (ARMS) PCR assay for rapid diagnosis of the species. The assay utilizes four primers in multiplex, with two outer universal primers, and two internal primers: one designed to target two adjacent SNPs (AA) present in B. tryoni and the other targeting adjacent SNPs present in B. neohumeralis (GG). The assay accurately discriminates between the two species, but their SNP genotypes are shared with other nontarget tephritid fruit fly species. Therefore, this assay is most suited to adult diagnostics where species confirmation is necessary in determining ambiguous surveillance trap catches; maintaining pure colony lines; and in Sterile Insect Technique management responses. [ABSTRACT FROM AUTHOR]

BACKGROUND: Gut microbiota mediating insect–plant interactions have many manifestations, either by provisioning missing nutrients, or by overcoming plant defensive reactions. However, the mechanism by which gut microbiota empower insects to survive by overcoming a variety of plant secondary metabolites remains largely unknown. Bactrocera minax larvae develop in immature citrus fruits, which present numerous phenolic compounds that challenge the larvae. To explore the role of gut microbes in host use and adaptability, we uncovered the mechanisms of phenol degradation by gut microbes using metagenomic and metatranscriptomic analyses, and verified the degradation ability of isolated and cultured bacteria. Research on this subject can help develop potential strain for the environmental friendly pest management operations. RESULTS: We demonstrated the ability of gut microbes in B. minax larvae to degrade phenols in unripe citrus. After antibiotic treatment, coniferyl alcohol and coumaric aldehyde significantly reduced the survival rate, body length and body weight of the larvae. The metagenomic and metatranscriptomic analyses in B. minax provided evidence for the presence of genes in bacteria and the related pathway involved in phenol degradation. Among them, Enterococcus faecalis and Serratia marcescens, isolated from the gut of B. minax larvae, played critical roles in phenol degradation. Furthermore, supplementation of E. faecalis and S. marcescens in artificial diets containing coniferyl alcohol and coumaric aldehyde increased the survival rate of larvae. CONCLUSION: In summary, our results provided the first comprehensive analysis of gut bacterial communities by high‐throughput sequencing and elucidated the role of bacteria in phenol degradation in B. minax, which shed light on the mechanism underlying specialist insect adaption to host secondary metabolites via gut bacteria. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bactrocera correcta is a quarantine pest that negatively impacts the fruit and vegetable industry. Differentiating B. correcta from similar species, especially in non‐adult stages, remains challenging. Rapid molecular identification techniques, such as recombinase polymerase amplification (RPA) combined with CRISPR/Cas12a and multienzyme isothermal rapid amplification with lateral flow dipstick (MIRA‐LFD), play a crucial role in early monitoring and safeguarding agricultural production. Our study introduces two methods for the rapid visual identification of B. correcta. RESULTS: Bactrocera correcta specific RPA primers, CRISPR RNA (crRNA), and the LFD probe were designed based on the cox1 genes. The RPA reaction conditions were optimized (at 37 °C for 8 min) for effective template DNA amplification. Two nucleic acid detection methods were established to visualize RPA. In the RPA‐CRISPR/Cas12a system, the optimal LbCas12a/crRNA concentration ratio was 200:400 nmol L−1. Successful amplification was determined by the presence or absence of green fluorescence following 15 min incubation at 37 °C. The MIRA‐LFD system achieved precise identification of the target species within 4 min at 37 °C. Both methods exhibited high specificity and sensitivity, allowing for detection from 1.0 × 10−1 ng μL−1 of DNA. Combined with rapid DNA extraction, rapid identification of individual B. correcta at different developmental stages was achieved, enhancing the practicality and convenience of the established methods. CONCLUSION: Our research findings demonstrate that both the RPA‐CRISPR/Cas12a and MIRA‐LFD methods for B. correcta detection was accurate and rapid (within 30 min and 10 min, respectively), at 37 °C. Our methods do not rely on expensive equipment, thus possess high practical value, providing improved identification solutions for port quarantine pests and field applications. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A study was conducted from 2020-2021 to identify the tephritid species in fields of Pumpkin, Bottle gourd, Mango, Guava, Ber and Citrus. Through Methyl Eugenol traps, two species namely Bactrocera dorsalis (Hendel) and Bactrocera zonata (Saunders) were collected. Through cue-lure traps, six species namely Zeugodacus tau (Walker), Zeugodacus cucurbitae (Coq.), Bactrocera rubigina (Wang and Zhao), Zeugodacus caudatus (Fabricus), Bactrocera divenderi Maneesh, Hancock and Prabhakar and Dacus longicornis (Wiedemann) were collected. Four species namely Zeugodacus tau (Walker), Zeugodacus cucurbitae (Coq.), Bactrocera dorsalis (Hendel) and Bactrocera minax (Enderlein) were recovered from infested fruits of pumpkin, bottle gourd, cucumber, ber and citrus. According to the Shannor-Weiner Diversity Index, species diversity was maximum in pumpkin among different fields and maximum in ber from infested fruits. Understanding the species diversity and determination in a crop ecosystem aid in strategising the management options. Clumped distribution was observed in several fields. [ABSTRACT FROM AUTHOR]

Copyright of Physiological Entomology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The hAT family transposable element, hopper, was originally discovered as a defective 3120‐bp full‐length element in a wild‐type strain of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), and subsequently a functional 3131‐bp element, hopperBdwe, was isolated from a white eye mutant strain. The latter study showed that closely related elements exist in melonfly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), a closely related subgenus, suggesting that hopper could have a widespread presence in the Bactrocera genus. To further understand the distribution of hopper within and beyond the B. dorsalis species complex, primer pairs from hopperBdwe and its adjacent genomic insertion site were used to survey the presence and relatedness of hopper in five species within the complex and four species beyond the complex. Based on sequence identity of a 1.94 kb internal nucleotide sequence, the closest relationships were with mutated elements from B. dorsalis s.s. and species synonymized with B. dorsalis including B. papayae, B. philippinensis and B. invadens, ranging in identity between 88.4% and 99.5%. Notably, Bactrocera carambolae (Drew & Hancock) (Diptera: Tephritidae), which is most closely related to B. dorsalis beyond the synonymized species, shared hopper identities of 97.3%–99.5%. Beyond the B. dorsalis complex, Z. cucurbitae, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) and Bactrocera zonata (Saunders) (Diptera: Tephritidae) shared identities of 83.1%–97.1%, while hopper was absent from the Bactrocera oleae (Gmelin) (Diptera: Tephritidae) strain tested. While the functional autonomous hopperBdwe element was not detected in these species, another closely related hopper element isolated from a B. dorsalis genetic sexing strain has an uninterrupted transposase open reading frame. The discontinuous presence of hopper in the Bactrocera genus has implications for its use for genomic manipulation and understanding the phylogenetic relationship of these species. [ABSTRACT FROM AUTHOR]

Bactrocera dorsalis and Bactrocera carambolae are major pests of various commodities that could cause significant losses, if not controlled. Insecticide usage is a common control carried out by farmers. The test was conducted to determine the toxicity level of several types of insecticides on the mortality of two different fruit fly species. The fruit fly population used in the study came from the collection owned by Center for Forecasting Plant Pest Organisms (BBPOPT), Karawang. The research method used was an experimental method with a Randomized Block Design. The test was carried out using the dry film method. The concentration ranges used were 0.02-1 ml/L fipronil insecticide, 0.01-0.6 ml/L ethion insecticide, 0.02-0.6 ml/L deltamethrin insecticide, and 0.02-0.8 ml/L lambda-cyhalothrin insecticide. The control treatment used was acetone alone. Each treatment was replicated thrice. Mortality was observed at 1, 3, 24, and 48 hours after treatment. Cumulative mortality at 48 hours after treatment was analyzed using probit to determine the LC50 and LC95 values at 48 hours. The results showed that the insecticide deltamethrin was the most toxic insecticide to B. carambolae with an LC50 value of 0.025 ml/L and an LC95 of 0.646 ml/L. Ethion was the most toxic insecticide for B. dorsalis with LC50 values of 0.046 ml/L and LC95 of 0.746 ml/L. The LC50 values of all insecticide treatments for two different species were below the recommended concentrations. [ABSTRACT FROM AUTHOR]

Simple Summary: Bactrocera dorsalis, Bactrocera cucurbitae, and Bactrocera tau are three invasive fruit fly pests that can cause significant economic damage to crops. Chemical agents have become the primary method for improving fruit fly management, leading to the development of insecticide resistance in these three species. Here, we assess the toxicity of a novel insecticide (fluralaner) and a commonly used insecticide (dinotefuran) against these three fruit fly species. Both insecticides exhibit strong lethal and sublethal effects on adult fruit flies and on the sex ratio of their offspring. Hence, fluralaner and dinotefuran can significantly control Bactrocera dorsalis, B. cucurbitae, and B. tau. These findings can help optimize insecticide application and ensure effective management of insecticide resistance. Fruit flies cause substantial economic damage, and their management relies primarily on chemical insecticides. However, pesticide resistance has been reported in several fruit fly species, the mitigation of which is crucial to enhancing fruit fly control. Here, we assess the toxicity of a novel insecticide (fluralaner) and a common insecticide (dinotefuran) against three fruit fly species, Bactrocera dorsalis (Hendel), Bactrocera cucurbitae (Coquillett), and Bactrocera tau (Walker). Both pesticides exhibit robust lethal and sublethal effects against all three fruit fly species, with fluralaner being more potent. Fluralaner and dinotefuran suppress the reproductive capacities and survival rates of fruit flies. However, at the 50% lethal concentration, fluralaner stimulates the reproductive capacity of B. dorsalis and the survival rate of B. tau. Fluralaner also causes significant transgenerational effects, impacting the offspring hatching rate of B. cucurbitae and B. tau and reducing the proportion of female offspring. Thus, both pesticides exhibit high potential for controlling fruit flies. However, their application should be tailored according to species variations and the diverse effects they may induce. Collectively, the findings of this study outline the sublethal effects of two insecticides against fruit flies, helping to optimize their application to ensure the effective management of insecticide resistance. [ABSTRACT FROM AUTHOR]

Simple Summary: Bactrocera tsuneonis (Miyake) is a significant pest of commercial citrus crops. It is a univoltine and oligophagous species widely distributed in Japan and China. In this study, the potential distribution of the B. tsuneonis population under current and different future climate change scenarios was modeled using MaxEnt software (v. 3.4.1) and optimized using R software (v. 4.3.2). Under current climate conditions, the potentially suitable areas were mainly concentrated in Central, South, and East China. The total area of habitats suitable for this pest was predicted to increase in the future climate scenarios. The centroid of the total suitable habitat for this pest gradually shifted westward and northward. Our findings provide new insights that could aid the monitoring of B. tsuneonis in China. The invasive pest, Bactrocera tsuneonis (Miyake), has become a significant threat to China's citrus industry. Predicting the area of potentially suitable habitats for B. tsuneonis is essential for optimizing pest control strategies that mitigate its impact on the citrus industry. Here, existing distribution data for B. tsuneonis, as well as current climate data and projections for four future periods (2021–2040, 2041–2060, 2061–2080, and 2081–2100) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) were obtained. The distribution of B. tsuneonis under current and different climate change scenarios in China was predicted using the optimized MaxEnt model, ArcGIS, and the ENMeval data package. Model accuracy was assessed using ROC curves, and the primary environmental factors influencing the distribution of the pest were identified based on the percent contribution. When the regularization multiplier (RM) was set to 1.5 and the feature combination (FC) was set to LQH, a model with lower complexity was obtained. Under these parameter settings, the mean training AUC was 0.9916, and the mean testing AUC was 0.9854, indicating high predictive performance. The most influential environmental variables limiting the distribution of B. tsuneonis were the Precipitation of Warmest Quarter (Bio18) and Temperature Seasonality (standard deviation ×100) (Bio4). Under current climatic conditions, potentially suitable habitat for B. tsuneonis in China covered an area of 215.9 × 104 km2, accounting for 22.49% of the country's land area. Potentially suitable habitat was primarily concentrated in Central China, South China, and East China. However, under future climatic projections, the area of suitable habitat for B. tsuneonis exhibited varying degrees of expansion. Furthermore, the centroid of the total suitable habitat for this pest gradually shifted westward and northward. These findings suggest that B. tsuneonis will spread to northern and western regions of China under future climate changes. The results of our study indicate that climate change will have a major effect on the invasion of B. tsuneonis and have implications for the development of strategies to control the spread of B. tsuneonis in China. [ABSTRACT FROM AUTHOR]

Background: The popular vegetable sweet gourd (Cucurbita moschata) is cultivated throughout Bangladesh. However, its yield is low owing to the severe infestation by fruit fly Bactrocera cucurbitae. This study investigated the toxicity of chemical insecticides and neem oil on fruit flies infesting sweet gourd. Methods: The repellency of adult fruit flies and larvae and the body weight and mortality of the larvae of the fruit fly were evaluated using three chemical insecticides-Karate 2.5 EC (cyhalothrin), Ripcord 10 EC (cypermethrin) and Shobicron 425 EC (profenofos Q+cypermethrin) and neem oil (azadirachtin). Result: The repellency rate of the fruit fly larvae varied from 20.0±0.0 to 86.7±6.7% and that of the adult fly from 13.3±6.7 to 73.3±6.7%; Shobicron 425 EC, at 2000 ppm, exhibited the best results in both the cases. The treatments negatively affected the weight of larvae compared to the control, where Shobicron 425 EC caused the lowest weight (7.8±0.2 mg). The insecticides at 24, 48 and 72 h after treatment demonstrated toxic effects on the larvae, where the LC50 values ranged from 742.5 (550.4-1060.5) to 2476.3 (2150.6-2954.7) ppm at 72 h after treatment. On the whole, Shobicron 425 EC demonstrated better efficacy than the other insecticides against fruit flies. [ABSTRACT FROM AUTHOR]

Predicting the risk of establishment and spread of populations outside their native range represents a major challenge in evolutionary biology. Various methods have recently been developed to estimate population (mal)adaptation to a new environment with genomic data via so‐called Genomic Offset (GO) statistics. These approaches are particularly promising for studying invasive species but have still rarely been used in this context. Here, we evaluated the relationship between GO and the establishment probability of a population in a new environment using both in silico and empirical data. First, we designed invasion simulations to evaluate the ability to predict establishment probability of two GO computation methods (Geometric GO and Gradient Forest) under several conditions. Additionally, we aimed to evaluate the interpretability of absolute Geometric GO values, which theoretically represent the adaptive genetic distance between populations from distinct environments. Second, utilizing public empirical data from the crop pest species Bactrocera tryoni, a fruit fly native from Northern Australia, we computed GO between "source" populations and a diverse range of locations within invaded areas. This practical application of GO within the context of a biological invasion underscores its potential in providing insights and guiding recommendations for future invasion risk assessment. Overall, our results suggest that GO statistics represent good predictors of the establishment probability and may thus inform invasion risk, although the influence of several factors on prediction performance (e.g., propagule pressure or admixture) will need further investigation. [ABSTRACT FROM AUTHOR]

Within a fruit, fruit fly larvae can be subject to scramble competition, in which density‐dependent effects can influence the fitness of subsequent adults. While there is significant research on tephritid interspecific larval competition, it has been conducted in invasive situations where the species are evolutionarily novel to each other. There has been no published research investigating larval competitive interactions between naturally coexisting, endemic species. We ran laboratory‐based, intraspecific and interspecific larval competition trials involving three co‐occurring Bactrocera species of differing genetic relatedness and also measured aspects of juvenile development rate to test possible mechanisms of competitive difference. Larval density had an influence on intraspecific competition in Bactrocera tryoni, Bactrocera neohumeralis and Bactrocera jarvisi, with a decreasing percentage of pupation with increasing larval density. Interspecific competition between B. tryoni and B. neohumeralis, and between B. tryoni and B. jarvisi was influenced by the interaction between species and density. The intensity of competition between B. tryoni and B. neohumeralis was minimal but high between B. tryoni and B. jarvisi. B. jarvisi produced larger eggs and had faster initial larval growth rates than the other two species, but it took the longest time for pupation to occur. Our results conflict with theory, as the greatest competition was observed between the two more distantly related species (B. tryoni and B. jarvisi) rather than between the two most closely related species (B. tryoni and B. neohumeralis). Further, and contrary to other studies, egg size, hatch rate and larval growth rate did not provide B. jarvisi with a competitive advantage; thus, larval size does not appear to be a mechanism of larval competition between B. tryoni and B. jarvisi. [ABSTRACT FROM AUTHOR]

Simple Summary: The genus Bactrocera contains invasive fruit fly species that lay eggs in and consume many important fruits and vegetables. Two tactics used to control these flies include the male annihilation and the sterile insect techniques. Bactrocera males are attracted to and feed on methyl eugenol, a chemical found in many plants. Baiting traps with a mixture of this chemical and an insecticide are used to annihilate males and, thereby, the pest population. The release of sterile males (achieved via irradiation) results in mating with wild females that results in inviable embryos. Feeding on ME (without insecticide) enhances the mating success of Bactrocera spp. males and suppresses their subsequent attraction to methyl eugenol + insecticide traps, enabling the simultaneous application of the male annihilation and the sterile insect techniques, which will boost the efficiency of control programs. However, methyl eugenol may pose human health risks, and this study demonstrated that feeding on an alternative and safer plant compound, β-caryophyllene, similarly led to the increased mating success of Bactrocera zonata and reduced their subsequent attraction to methyl-eugenol-baited traps. The peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae), is an economically important polyphagous quarantine pest of horticultural crops endemic to South and Southeast Asia. Methyl eugenol (ME), a naturally occurring phenylpropanoid, is a male attractant used to lure and (when mixed with an insecticide) annihilate the males from the wild population, a method of pest control termed the male annihilation technique (MAT). ME is reported to enhance the mating success of sterile males of Bactrocera spp., which is critical for enhancing the effectiveness of the sterile insect technique (SIT). The suppressed response of ME-treated males to ME-baited traps/devices allows the simultaneous application of the MAT and SIT, increasing the efficiency of area-wide integrated pest management (AW-IPM) programs. However, ME treatment in sterile males in SIT facilities is logistically difficult. β-caryophyllene (BCP) is a widely occurring, safer plant compound and is considered suitable for treating males in SIT facilities. Here, we demonstrate that BCP feeding enhanced B. zonata male mating success to the same extent as ME feeding. Feeding on BCP suppressed the male's subsequent attraction to ME-baited traps, but not to the same degree as feeding on ME. The results are discussed and BCP is suggested as an alternative to ME for the concurrent use of the MAT and SIT. [ABSTRACT FROM AUTHOR]

Early detection and monitoring of the internal aspects of Bactrocera zonata infestation in fruits and vegetables are important for sustainable agriculture. The present study depends on the non-destructive detection of B. zonata damage in peach fruits using a high-resolution spectroradiometer to characterize the spectral reflectance pattern of peach fruits in healthy and infested fruits with different pest stages, including egg stage and larval instars. Additionally, five vegetation indices were used to detect infestation. Laboratory trials were carried out to investigate the entomopathogenic nematodes (EPNs) pathogenicity, gamma-irradiated and unirradiated Steinernema carpocapsae, and Heterorhabditis bacteriophora against B. zonata larvae and pupae. The spectral reflectance pattern of healthy peach fruit samples was higher than that of all infested samples. The peak level of light reflection for a peach fruit in a healthy state was observed at 750 nm. Conversely, at 1050 nm, the reflectance was low, and it reached its minimum level at 2150 nm for infested peach fruit. Green spectral zones achieved the highest level of discrimination between healthy and infested peach fruit. There was no noticeable distinction between the blue and SWIR-1 zones. However, SWIR-2, red, and NIR spectral zones exhibited a significant difference as they could differentiate between healthy and infested peach fruit. The normalized pigment chlorophyll index (NPCI) was the best plant index employed in pest identification. As the concentration of EPNs increased, the proportion of mortality additionally increased. Furthermore, this study revealed that irradiation of S. carpocapsae juveniles boosted their pathogenicity toward larvae. The LC50 value decreased from 569.39 infective juveniles (IJs)/larva to 433.43 IJs/larva. There was no significant difference in pupae. However, irradiation of H. bacteriophora juveniles negatively impacted larvae, increasing the LC50 value from 1608.04 IJs/ larvae to 2295.73 IJs/larvae by 1.4 fold. Additionally, it significantly affected pupae, as it caused the lowest LC50 value of 402.66 IJs/pupae. The results of this study confirmed hyperspectral data’s utility in the early prediction of fruit infestation and differentiated between different stages of B. zonata infestation. Similarly, applying irradiation to EPNs significantly impacts the control of B. zonata. [ABSTRACT FROM AUTHOR]

The Oriental fruit fly Bactrocera dorsalis (Hendel), a global pest that can decimate regional fruit industries and elicit international quarantines, has been the subject of considerable taxonomic confusion. Previous phylogenetic work revealed that B. dorsalis is part of a monophyletic clade containing 12 species. We present restriction site‐associated DNA sequencing (RAD‐seq) genomic data for 2,292 specimens, which unequivocally supports the delimitation of two new species, here described as Bactrocera borneoensissp. n. Doorenweerd & San Jose and B. incognitasp. n. Doorenweerd & San Jose. We additionally obtained 1,985 Cytochrome C oxidase I (COI) sequences for a subset of the specimens to see which species can be diagnosed with this mtDNA marker and conclude that B. dorsalis, B. incognita, B. carambolae Drew & Hancock, B. raiensis Drew & Hancock, B. occipitalis (Bezzi) and B. kandiensis Drew & Hancock cannot be identified reliably using COI due to introgression—but the newly described species B. borneoensis can be identified using COI. The supposed innocuous species B. raiensis distribution is underestimated in Asia and Africa. Bactrocera kandiensis COI genotypes occur in African flies, but RAD‐seq data confirm that these are B. dorsalis with introgressed B. kandiensis COI. The phylogenomic dataset brings new light to the extent of the B. dorsalis s.l. clade and the morphological and molecular confusion based on COI. This will have ramifications for ecological data—including host and distribution ranges—associated with B. dorsalis s.l. clade species, pest identification protocols and our understanding of the economic importance of the various species in the clade. [ABSTRACT FROM AUTHOR]

The Tephritidae family causes damage to fruits in tropical and subtropical regions around the world, with Bactrocera minax Enderlein (Diptera: Tephritidae) widely distributed in China, causing severe economic damage to Chinese citrus. Currently, preventing the rapid spread of B. minax remains an effective strategy to control it as the climate continues to warm in the future. In this context, it is crucial to understand the potential geographic range of B. minax under climate change. We used meta-analysis to assess the survival of Tephritidae insects under temperature stress. We also used the maximum entropy (MaxEnt) model to predict the suitable regions and migration trajectories of B. minax in China under current and future climatic conditions. Through comprehensive analysis of the experimental data, we found that the survival rate of Tephritidae insects in the suitable temperature range showed an increasing trend with the increase in warming extent. Using the MaxEnt model, we observed that the highly suitable area, as well as the moderately suitable area of B. minax , were expanding in all 3 future climate scenarios, with the distribution moving toward the high latitude region and the coastal region of China. Our results also indicate that temperature and precipitation contribute more to the model in the current year. Combining multiexperiment data, our study demonstrates that the potential distribution of B. minax in China will expand under future climate warming scenarios, and these predictions will provide important information for monitoring B. minax and informing managers in developing control strategies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bactrocera minax is a devastating pest of citrus fruits. However, there have been no effective control measures before. Few reports on the sex pheromones of B. minax are available. RESULTS: In this study, nine of the volatile compounds in adult females were identified using headspace solid‐phase microextraction (HS‐SPME) in combination with gas chromatography–mass spectrometry (GC–MS). Among them, d‐limonene, caprolactam, 2‐Nitro‐1H‐imidazole, and creatinine could evoke antennal responses in males. Field bioassays showed that only d‐limonene could lure male flies, with a relative lure rate of 78.18% in all tested samples, which was significantly higher than that of paraffin oil control, while all volatile compounds did not have any lure effective to female flies. Moreover, d‐limonene was diluted with paraffin oil into differential concentrations, the lure effect on males was better at 100, 500, and 800 μL d‐limonene mL−1 than pure d‐limonene (1000 μL mL−1). The relative male lure rate of d‐limonene at 100 μL mL−1 was 85.88%, which was significantly higher than that of food−baits (14.12%) on day 3. However, d‐limonene was unattractive to female and male Bactrocera dorsalis and Zeugodacus tau. Further kinetic analysis showed that female adults released d‐limonene around 15‐day post eclosion. Electroantennography 1 results showed that 500 μL mL−1 d‐limonene evoked the strongest responses to antennae of 10‐ to 25‐day‐old male flies. CONCLUSION: Our results indicated that d‐limonene could be a sex pheromone from female flies of B. minax, and it could be used as a male‐specific sex attractant for B. minax. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The sterile insect technique can suppress and eliminate population outbreaks of the Australian horticultural pest, Bactrocera tryoni, the Queensland fruit fly. Sterile males mate with wild females that produce inviable embryos, causing population suppression or elimination. Current sterile insect releases are mixed sex, as the efficient removal of unrequired factory-reared females is not yet possible. In this paper, we assessed the known Drosophila melanogaster temperature-sensitive embryonic lethal alleles shibire (G268D, shits1) and RNA polymerase II 215 (R977C, RpII215ts) for potential use in developing B. tryoni genetic sexing strains (GSS) for the conditional removal of females. Complementation tests in D. melanogaster wild-type or temperature-sensitive genetic backgrounds were performed using the GAL4–UAS transgene expression system. A B. tryoni wild-type shibire isoform partially rescued Drosophila temperature lethality at 29°C by improving survivorship to pupation, while expressing B. tryoni shits1 failed to rescue the lethality, supporting a temperature-sensitive phenotype. Expression of the B. tryoni RpII215 wild-type protein rescued the lethality of D. melanogaster RpII215ts flies at 29°C. Overexpressing the B. tryoni RpII215ts allele in the D. melanogaster wild-type background unexpectedly produced a dominant lethal phenotype at 29°C. The B. tryoni shibire and RpII215 wild-type alleles were able to compensate, to varying degrees, for the function of the D. melanogaster temperature-sensitive proteins, supporting functional conservation across species. Shibire and RpII215 hold potential for developing insect strains that can selectively kill using elevated temperatures; however, alleles with milder effects than shits1 will need to be considered. [ABSTRACT FROM AUTHOR]

This study examines the impact of Heterorhabditis indica entomopathogenic nematodes on mature larvae of the peach fruit fly, Bactrocera zonata (Saunders), and the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), both of which are highly detrimental species in the Tephritidae family. The investigation is conducted in a laboratory setting using two types of soil: sandy loam and sand. The research focuses on the virulence and biochemical effects of the nematodes. The results indicate that H. indica is more effective in sandy loam soil than sandy soil. This is supported by the LC50 values (the lethal concentration that kills 50% of the tested organisms) of 566.656 Infective Juveniles/ml for B. zonata and 250.53 Infective Juveniles/ml for C. capitata in sandy loam soil, whereas the corresponding values in sandy soil were 1149.051 and 701.839 Infective Juveniles/ml, respectively. Consequently, C. capitata larvae are more susceptible to entomopathogenic nematodes than B. zonata larvae. The infection by the nematodes also leads to changes in specific enzymatic activities of the larvae. This includes significant reductions in amylase, trehalase, and acetylcholine esterase, alongside an increase in invertase activity. Moreover, varying decreases are observed in chitinase, acid phosphatase, and alkaline phosphatase activities. In conclusion, the nematodes effectively reduce the emergence of adult flies by targeting the final stages of insect development. Furthermore, they offer an eco-friendly alternative to chemical pesticides. Entomopathogenic nematodes is an alternative biological control for fruit flies. H. indica is a soil control agent and adapted well to field situations. H. indica suppressed fruit fly larvae and could restrict their population expansion. Individuals of C. capitata were more comparatively susceptible than B. zonata ones. H. indica caused disturbance in specific enzymatic systems of both species larvae. [ABSTRACT FROM AUTHOR]

The melon fly, Bactrocera cucurbitae (Coquillett) (Tephritidae: Diptera), is an invasive pest that poses a significant threat to agriculture in Africa and other regions. Flies are known to use their olfactory systems to recognise environmental chemical cues. However, the molecular components of the chemosensory system of B. cucurbitae are poorly characterised. To address this knowledge gap, we have used nextgeneration sequencing to analyse the antenna transcriptomes of sexually immature B. cucurbitae adults. The results have identified 160 potential chemosensory genes, including 35 odourant-binding proteins (OBPs), one chemosensory protein (CSP), three sensory neuron membrane proteins (SNMPs), 70 odourant receptors (ORs), 30 ionotropic receptors (IRs), and 21 gustatory receptors (GRs). Quantitative real-time polymerase chain reaction quantitative polymerase chain reaction was used to validate the results by assessing the expression profiles of 25 ORs and 15 OBPs. Notably, high expression levels for BcucOBP5/9/10/18/21/23/26 were observed in both the female andmale antennae. Furthermore, BcucOROrco/6/7/9/13/15/25/27/28/42/62 exhibited biased expression in the male antennae, whereas BcucOR55 showed biased expression in the female antennae. This comprehensive investigation provides valuable insights into insect olfaction at the molecular level and will, thus, help to facilitate the development of enhanced pest management strategies in the future. [ABSTRACT FROM AUTHOR]

An investigation was conducted to study the seasonal occurrence of Bactrocera spp. (Diptera, Tephritidae) in the mango orchards of College of Agriculture, Kerala Agricultural University, Padannakkad. Surveillance of fruit flies was conducted using bottle traps with methyl eugenol lure. A total of 10,546 fruit flies were trapped with the predominant species being Bactrocera dorsalis. Four species viz., B. dorsalis, Zeugodacus tau, B. zonata and Z. cucurbitae were identified from the population collected in that order of dominance. Out of fruit flies captured, B. dorsalis, accounted for 97.97 per cent. The highest weekly population of fruit flies was recorded in the 14th standard meteorological week (SMW) of 2022 from April 2 to 8, 2022, with 793 fruit flies, while the lowest population in 50th SMW from December 10 to 16, 2021 with only one fruit fly. The monthly average population was highest in May with 667.5 flies per month and lowest in December with 16 flies per month. During the period of host availability (April to June), the population of fruit flies exhibited significant positive correlation with minimum temperature (0.805), and a significant negative correlation with soil temperature (-0.512). There was a negative correlation with maximum temperature (-0.329) and wind speed (-0.192) while a positive correlation was observed with rainfall (+0.204). [ABSTRACT FROM AUTHOR]

Valorisation of rearing residue of peach fruit flies (PFF) Bactrocera zonata into high-value products by yellow mealworm (YMW) Tenebrio molitor could consider a sustainable strategy for developing the PFF management using Sterile Insect Technique (SIT). Different ratios of PFF rearing residue (PF) in substantial amounts of hen feed (HF) were used for rearing YMW larvae. The quality control and performance parameters of YMW were assessed. It was noticed that the feeding trials resulted from promising body mass as compared to the control treatment (hen feed). While no progeny of YMW adult was produced when fed on PF 1 diet (100 % rearing residue). Larval and pupal duration of YMW was insignificantly prolonged when reared on PF3 and PF4 diets that contained 50 and 25 % rearing residue, respectively as compared to the HF diet (control). All experimental diets exhibited high rates of pupal production; however, the pupal yields were desirable during larval survival. High percentages of food consumed and food assumed to be assimilated by YMW larvae fed on PF4. There were no significant differences were recorded in the live and dry weight gain of YMW larvae fed on PF4 and HF. Our findings suggest that PFF rearing residue was effective dietary for YMW and could significantly diminish the SIT cost and environmental savings. [ABSTRACT FROM AUTHOR]

The increasing number of tephritid pest invasions worldwide highlights the importance of interspecific interactions among tephritid pests. The melon fly [Zeugodacus cucurbitae (Coquillett)], the pumpkin fruit fly [Zeugodacus tau (Walker)], and the oriental fruit fly [Bactrocera dorsalis (Hendel)] (all Diptera: Tephritidae) are neotropical fruit flies with overlapping distributions. Their interactions during mating hours have rarely been observed in nature due to their nocturnal behavior. Here, laboratory studies were conducted under no‐choice and choice conditions to quantify interspecific mating. The interactions during mating hours resulted in interspecific mating, which reduced conspecific mating success and interrupted mating activity patterns. Successful interspecific mating pairs of Z. cucurbitae and Z. tau were recorded in no‐choice and choice tests. Interspecific mating between male Z. cucurbitae and female Z. tau significantly reduced conspecific mating in Z. tau. Observations of the diel mating activity patterns showed that male Z. cucurbitae initiated calling behaviors earlier than Z. tau males, giving Z. cucurbitae more chances to court Z. tau. Though males of neither Zeugodacus species formed mating pairs with B. dorsalis, Zeugodacus males reduced conspecific mating in B. dorsalis in the choice trials. Thus, interspecific interactions among Z. cucurbitae, Z. tau, and B. dorsalis affected conspecific mating; interrupted conspecific mating activity patterns were recorded in all three species. This information could be used to improve management practices. [ABSTRACT FROM AUTHOR]

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BACKGROUND: The peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae) is an economically important polyphagous, quarantine pest endemic to South and South‐East Asia. The male annihilation technique (MAT) and the sterile insect technique (SIT) are environmentally benign techniques used to suppress fruit fly populations on an area‐wide basis. The MAT and SIT are typically used sequentially to avoid killing released sterile males; however, MAT and SIT potentially could be used simultaneously and thereby increase the overall efficiency of control programmes. Mating competitiveness of sterile males against wild counterparts is critical for the success of the SIT. Feeding on a semiochemical, methyl eugenol (ME) has been reported to enhance the male mating performance of many Bactrocera spp., including B. zonata, but its use in SIT operational programmes is limited owing to the absence of a viable delivery system. RESULTS: In the present study, we demonstrated that ME aromatherapy, a practical method for large‐scale delivery of ME olfactorily, enhances the mating success of treated B. zonata males. ME aromatherapy application to 5‐day‐old immature males for a duration of 5 h resulted in increased mating success of males tested when sexually mature, compared to untreated males. The ME‐aromatized males also exhibited reduced attraction to ME‐lure. CONCLUSION: A practical delivery system for applying ME by aromatherapy to mass‐reared males was developed. ME‐aromatherapy enhanced male mating success and suppressed their subsequent attraction to ME, thus enabling the application of MAT and SIT at the same time. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Fruit flies of the genus Bactrocera are the most damaging pests of horticultural crops, leading to severe economic losses affecting the national income of various countries, especially Sudan. Bactrocera dorsalis (Hendel) and Bactrocera zonata (Saunders) were reported in Sudan in 2005 and 2012, respectively. Only the male annihilation technique (MAT) is applied in Sudan to manage the two Bactrocera species. Field experiments were conducted to evaluate the response of B. dorsalis, B. zonata and Zeugodacus cucurbitae to three food-based (Mazoferm, GF-120 and Torula yeast) attractants via McPhail traps at two sites in the Gezira State, Sudan. Another trial was undertaken to determine the effect of spot spraying Mazoferm + Spinosad on control B. zonata. The results showed that food-based attractants lured both sexes of the abovementioned fruit flies with specific attraction to females (74.5, 67.5 and 68.1% to Mazoferm E802, GF-120 and Torula yeast, respectively). At the first site, B. zonata responded in high numbers to Mazoferm E802, followed by Torula yeast and GF-120, while it responded equally to Mazoferm and Torula yeast at the second site. B. dorsalis responded positively to Mazoferm, followed by Torula yeast and GF-120, while Z. cucurbitae was attracted to Mazoferm E802, GF-120 and Torula. Spraying Mazoferm E802 + Spinosad significantly reduced the population of B. zonata (FTD) and suppressed the infestation level of guava fruits (fruit flies/kg of fruits) compared to those in unsprayed orchards. The spot bait application technique is an environmentally friendly approach that reduces fruit fly infestation levels, protects produce, decreases contamination and pollution and increases the income of poor farmers. [ABSTRACT FROM AUTHOR]

Fruit flies belonging to the Bactrocera dorsalis species complex pose a significant threat to mangoes and other crops in the Philippines and worldwide. Identifying cryptic species within this complex is challenging, particularly when relying solely on morphological analysis. In this study, we sequenced two fragments of the nuclear 18S and ITS2-28S rRNA genes from specimens of Bactrocera dorsalis Hendel collected in the Philippines to assess their applicability for species diagnostics. Subsequent sequencing and analysis revealed that the 18S and 28S rRNA gene fragments matched B. dorsalis sequences in NCBI but also displayed high similarity with other Bactrocera and insect species. On the other hand, sequences of the ITS2 segment showed hits specific to B. dorsalis. Further analysis of the 18S rRNA gene in fruit flies collected from various sources and host plants in the country suggests conserved sequences among Bactrocera samples, irrespective of collection site and host plant species. In conclusion, our findings suggest that, among the tested nuclear DNA fragments, only the ITS2 demonstrates sufficient species-level nucleotide variation for effective use as a molecular diagnostic marker for B. dorsalis identification. [ABSTRACT FROM AUTHOR]

Chinese citrus fly, Bactrocera minax, (Enderlin) (Tephritidae: Diptera) is univoltine pest causing severe damage in citrus fruits. Longivity in different carbohydrate diets and morphometrics of adult Chinese citrus fly (CCF) was studied in uncontrolled laboratory room in Agriculture and Forestry University, Chitwan, Nepal. The result showed that the emergence of CCF was the highest (88%) for the pupa weighing more than 0.076 g with male and female emergence ratio of 1:2.1 followed by pupal weight of 0.049-0.076 g with emergence of 82.1%. The maximum population emerged at the last week of March, 2021. The adult emergence was recorded 66-90% at the additional moisture content of 15-20% in oven-dried soil with no adult emergence in completely oven dried soil. The adult longivity was 17.90 ± 1.80 days for female adult in 10% sucrose solution and was 15.09 ± 1.49 days for male adult in 10% jaggery solution. Length of Chinese citrus fly pupa was 7.46 ± 0.30 mm while breadth was 0.97 ± 0.004 mm with average weight of 0.078 ± 0.002 g. Similarly, length of female was 16.09 ± 0.27 mm including ovipositor (4.28 ± 0.41 mm) which was 43.8% higher than male fly (11.39 ± 0.16 mm). Wing span of male was 2.50 ± 0.006 cm and of female was 2.72 ± 0.10 cm where female had 8.8% wider wing span compared to male. The study findings are useful in comparing characters of B. minax with other fruit fly species to develop the specific management practices of CCF. [ABSTRACT FROM AUTHOR]

The tribe Dacini, within the sub-family Dacinae of the Tephritidae family, includes major fruit flies within the genera Zeugodacus, Bactrocera, and Dacus. The Bactrocera spp., which were previously grouped into subgenera Zeugodacus and Bactrocera, have been treated as separate genera in recent years. These dacine flies are widely spread in fruits and vegetables. The first dacine fruit fly, i.e. D. (Callantra) nepalensis reported in 1964 from Nepal is still a holotype. Altogether, 27 species have been reported in Nepal from three genera-Dacus (6), Zeugodacus (8), and Bactrocera (13), of which 10 species are attracted to cue-lure, 7 species to methyl eugenol, 2 species to zingerone, 1 species to lati-lure and 5 species to more than one lure, while lure for 2 species are unknown. Among them, 7 species are oligophagous pests, 6 species are polyphagous pests, and the pest status of 14 species is unknown. Fruit fly infestation and damage have been recorded in different crops such as; 5 species on cucurbits, 2 species on different fruits, 4 species on different fruits and vegetables, 1 species on citrus fruits, and 1 species on solanaceous vegetables. Three species; Z. cucurbitae, Z. tau, and B. minax, have been recorded from infested fruit cultures of cucurbits and sweet orange too. However, pest status, preferred hosts, and biology of many species remain yet to be explored and reported from Nepal. Further studies are necessary focusing on fruit fly species of economic importance concerning host preference for developing appropriate management strategy. Efforts are needed to identify the fruit fly species that inflict actual damage to the hosts. [ABSTRACT FROM AUTHOR]

Fruit flies (Diptera: Tephritidae) are important quarantine pests that may cause even up to 100 per cent yield losses in cucurbits. Among them, Zeugodacus cucurbitae (Coquillett) and Dacus ciliatus Loew are the serious pests of cucurbits. Survey was conducted in Coimbatore (11°14'60.00"N; 77°18'60.00"E) and Dharmapuri (40°26.767'N; 79°58.933'W) districts of Tamil Nadu, India, during 2017-2018, in the fields of snake gourd, ridge gourd and bitter gourd. Approximately 10 infested fruits from each vegetable ecosystem were collected and placed in glass cages for 15-20 days. Emerged flies were identified by using the taxonomical keys and confirmed through molecular characterization. The overlapping abdominal tergites are the key character to distinguish the Bactrocera genus from Dacus. Further, the presence of median vittae, r-m cross vein on forewing pecten on the male's abdomen and black facets on the face are the identification characters for Z. cucurbitae. Whereas, D. ciliatus with two facial spots. The amplicon size of collected fruit flies was found to be 480 bp. The population of both Z. cucurbitae and D. ciliatus showed a significantly positive correlation with rainfall and relative humidity. Whereas, it was negative with respect to maximum temperature and sunshine hours in both the locations. [ABSTRACT FROM AUTHOR]