Tephritidae Research Articles

Assessing the Impact of Tephritid Fruit Flies on Diverse Fruit and Vegetable Crops in West Bengal's Terai Agro-ecological Region

The flies belong to the family Tephritidae of the Insect order Diptera and are referred to as Fruit flies because they infest various fruits and vegetables. Globally, Dacinae fruit flies of the genus Bactrocera Macquart are one of the most important pests of fruits and vegetables. A study was conducted during 2021, to assess the association of tephritids with different fruits and vegetables like Ber, Citrus, Guava, Mango, Bottle gourd, Cucumber and Pumpkin. A total of nine species were collected by installing traps comprising of sex attractants such as Cue-lure, Methyl Eugenol and by rearing from Infested fruits. Among nine, six species were collected through cue-lure traps 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). Two species were collected through methyl eugenol traps namely Bactrocera dorsalis (Hendel) and Bactrocera zonata (Saunders). Four species namely Zeugodacus tau (Walker), Zeugodacus cucurbitae (Coq.), Bactrocera dorsalis (Hendel) and Bactrocera minax (Enderlein) were recovered from infested fruits of ber, citrus, bottle gourd, cucumber and pumpkin. Species richness in different fields was maximum in citrus and from the recovery of infested fruits maximum in ber. Species composition of Z.tau was maximum in pumpkin, and bottle gourd and B. dorsalis were maximum in mango, guava, ber and citrus. Species composition of Z. tau were recovered maximum from infested pumpkin and cucumber, Z. cucurbitae were recovered maximum from infested bottle gourd and B. dorsalis were recovered maximum from infested ber and citrus fruits. Relative abundance of Z. tau was recorded maximum in pumpkin and bottle gourd and B. dorsalis was recorded maximum in mango, guava, ber and citrus. A relative abundance of Z. tau was recovered maximum in pumpkin and cucumber-infested fruits, Z. cucurbitae were recovered maximum from bottle gourd-infested fruits and B. dorsalis were recovered maximum from ber and citrus-infested fruits. In different fields, species evenness was observed maximum in citrus and from recovery of infested fruits maximum in ber.

Invertebrate and fungal associations of the pastoral weed, Madagascar ragwort, Senecio madagascariensis Poir, in Northland, New Zealand, and implications for biocontrol

ABSTRACT Senecio madagascariensis Poir is now found in New Zealand colonising pastoral habitats north of a latitude 35.5°S. This prolific, continuous flowering, toxic perennial weed may not have reached its potential geographic range in New Zealand and is poorly controlled by herbicides. Prior to embarking on a biocontrol programme for this weed, we present a survey of invertebrates and diseases which found relatively few natural enemies and no specialised herbivores or plant pathogens in its current range in New Zealand. The most significant herbivorous insect pests were Hemipteran sap-suckers from 8 families. Percentage infestation of seedheads by the multivoltine tephritid fly, Sphenella rufriceps (Macquart) ranged from 16.7% to 49.8%. Fewer stems of S. madagascariensis were found in plants infected by the fungus, Puccinia lagenophorae Cooke. A search in Western Province (RSA) and in Madagascar for biocontrol control agents host specific to S. madagascariensis is planned.

Addition of ammonium acetate to torula yeast borax and its effect on captures of three species of economically important fruit flies (Diptera: Tephritidae).

Many countries operate continuous trapping programs to detect invasive fruit flies (Diptera: Tephritidae) that threaten fruit and vegetable production. Food-based attractants are an important component of these programs, as they are generalized baits that attract both sexes of all target species. However, food baits are considered weak attractants, and the development of improved food attractants would benefit surveillance efforts. Prior work on protein bait sprays demonstrated that the addition of ammonium acetate increased their attractiveness to tephritid fruit flies, and the present study was conducted to determine whether adding ammonium acetate to torula yeast borax solution (a commonly used food bait) similarly increased its attractiveness. Four field experiments were performed in Hawaii comparing captures of Ceratitis capitata (Wiedemann), Bactrocera dorsalis (Hendel), and Zeugodacus cucurbitae (Coquillett) in Multilure traps baited with standard torula yeast borax solution or with the standard solution plus 1% ammonium acetate. Captures of C. capitata and B. dorsalis were significantly higher for the ammonium acetate-supplemented solution, while results for Z. cucurbitae were inconsistent. In one experiment involving only C. capitata, an additional bait having 5% ammonium acetate was included, and captures for both 1% and 5% ammonium acetate exceeded the standard solution but did not differ from one another. Sex ratios of captured flies were similar between food baits for all three species. These results are compared with similar studies on Anastrepha spp., and implications for surveillance programs are discussed.

Wind effects on individual male and female Bactrocera jarvisi (Diptera: Tephritidae) tracked using harmonic radar.

Wind affects the movement of most volant insects. While the effects of wind on dispersal are relatively well understood at the population level, how wind influences the movement parameters of individual insects in the wild is less clear. Tephritid fruit flies, such as Bactrocera jarvisi, are major horticultural pests worldwide and while most tephritids are nondispersive when host plants are plentiful, records exist for potentially wind-assisted movements up to 200 km. In this study, harmonic radar (HR) was used to track the movements of both male and female lab-reared B. jarvisi in a papaya field. Overall flight directions were found to be correlated with wind direction, as were the subset of between-tree movements, while within-tree movements were not. Furthermore, the effect of wind direction on fly trajectories varied by step-distance but not strongly with wind speed. Mean path distance, step distance, flight direction, turning angle, and flight propensity did not vary by sex. Both male and female movements are well fit by 2-state hidden Markov models further supporting the observation that B. jarvisi move differently within (short steps with random direction) and between (longer more directional steps) trees. Data on flight directionality and step-distances determined in this study provide parameters for models that may help enhance current surveillance, control, and eradication methods, such as optimizing trap placements and pesticide applications, determining release sites for parasitoids, and setting quarantine boundaries after incursions.

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.

Male and female age affects the reproductive potential of two tephritid flies

AbstractIn insects, aging produces deterioration in physiological and cellular functioning, affecting their reproductive potential. Anastrepha fraterculus and Ceratitis capitata are two fruit fly species where overwintering adults resume their reproductive activity in spring, giving old individuals the possibility of mating with young adults. Most age studies focus on male reproductive capacity; however, we lack information on how the interaction between the ages of both sexes can determine post‐mating processes. Here, we studied sex and age effects on (i) female fecundity and fertility, (ii) failure to leave viable offspring (reproductive failure), and (iii) female remating behavior. We found that young pairs of both species had higher fecundity, but young C. capitata males mated with old females had the lowest fecundity. This suggests that overwintering flies in this species will not substantially contribute to the next generation. We also found in C. capitata more prevalent reproductive failure in hetero‐age combinations, which could be due to age recognition between mates, resulting perhaps in differential ejaculate allocation. Copula duration was positively associated with female age, yet it was longer for older A. fraterculus females and shorter for C. capitata females. Female remating was lower when young females mated with old males in C. capitata. This would imply that males perceive young females of “good quality” and thus invest and transfer all the ejaculate possible to ensure the delay of renewal of female receptivity. Aging does not always cause a decline in reproductive potential, which may be important in species that overwinter as adults. Complex interactions between female physiology and male ejaculate senescence can impact postcopulatory behaviors that affect reproductive success for both sexes.

Effect of temperature and humidity on insect DNA integrity evaluated by real-time PCR.

Insects collected in dry traps can degrade rapidly, especially in warm, humid environments where many biodiversity and biosecurity surveillance activities are undertaken. Degradation can severely impact diagnostics, as trap catches can become difficult to identify to species level using morphological characters or, of increasing importance, molecular approaches. This is especially problematic for biosecurity surveillance of exotic tephritid fruit flies, where diagnostics are heavily reliant on morphological characters. We tested the effects of differing temperature and humidity conditions on mock samples of tephritid fruit flies in a controlled environment and compared our results to field trap catches. DNA degradation was quantified using real-time PCR assays, including one assay newly developed and tested here. We observed a correlation between increasing DNA degradation and increasing temperature and humidity. The greatest DNA degradation occurred under combined high humidity (90% relative humidity) and constant high temperature (35 °C). Unexpectedly, fluctuating temperature did not have a significant impact on DNA. Other factors, such as trap design, time in the field, and rainfall, did not significantly correlate with DNA quality across the field samples tested. When plotted against mock samples, field samples clustered together, with no clear pattern or predictability regarding the quantity of DNA preserved, indicating other untested environmental variables may be at play. Predictably, increased exposure time was found to have a detrimental effect on DNA quality for all treatments. These findings will improve the delivery of surveillance activities through the implementation of shorter trap clearance timeframes and improved trap designs and procedures.

Field studies of synthetic food-based attractants for detecting invasive fruit flies (Diptera: Tephritidae)

True fruit fly species (Diptera: Tephritidae) threaten the production and international trade of many fruit and vegetable crops. Many fruit fly-free regions operate trapping programs for the detection of these invasive pests, and food baits are an important component of detection trapping. A torula yeast-borax (TYB) solution has been widely used as a food bait, but it has a relatively short field longevity and is generally replaced every 1–2 weeks. Dry synthetic food-based attractants, consisting of ammonium acetate, putrescine, and trimethylamine, have been developed and appear to be effective for several months. Initially, the three components were presented in individual sachets within a trap, but to ease handling ‘all-in-one’ dispensers have been developed that contain all three components. While a logistical improvement, there are few data that compare captures between the standard TYB solution and these combination dispensers. This study presents the results of field experiments assessing the relative effectiveness of three ‘all-in-one’ dispensers of synthetic food-based attractants (i.e., Scentry food cones, Suterra Unipaks, and Susbin Difusors) in trapping three major pest species of tephritid fruit flies in Hawaii. The data presented here indicate that, with respect to C. capitata, the Difusor lures performed as well as TYB, while the Unipaks and food cones were significantly less attractive than TYB. With respect to B. dorsalis and Z. cucurbitae, none of the synthetic baits tested was as effective as TYB. Thus, among the baits studied here, TYB was most effective in attracting all three of the target species.

Adaptation to host plants modulates the dependence of tephritid fruit flies on their gut bacterial communities

Adaptation to host plants modulates the dependence of tephritid fruit flies on their gut bacterial communities

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.

Tracking and modeling the movement of Queensland fruit flies, Bactrocera tryoni, using harmonic radar in papaya fields

Determining movement parameters for pest insects such as tephritid fruit flies is critical to developing models which can be used to increase the effectiveness of surveillance and control strategies. In this study, harmonic radar was used to track wild-caught male Queensland fruit flies (Qflies), Bactrocera tryoni, in papaya fields. Experiment 1 continuously tracked single flies which were prodded to induce movement. Qfly movements from this experiment showed greater mean squared displacement than predicted by both a simple random walk (RW) or a correlated random walk (CRW) model, suggesting that movement parameters derived from the entire data set do not adequately describe the movement of individual Qfly at all spatial scales or for all behavioral states. This conclusion is supported by both fractal and hidden Markov model (HMM) analysis. Lower fractal dimensions (straighter movement paths) were observed at larger spatial scales (> 2.5 m) suggesting that Qflies have qualitatively distinct movement at different scales. Further, a two-state HMM fit the observed movement data better than the CRW or RW models. Experiment 2 identified individual landing locations, twice a day, for groups of released Qflies, demonstrating that flies could be tracked over longer periods of time.

Host range of a parasitoid wasp is linked to host susceptibility to its mutualistic viral symbiont.

Parasitoid wasps are one of the most species-rich groups of animals on Earth, due to their ability to successfully develop as parasites of nearly all types of insects. Unlike most known parasitoid wasps that specialize towards one or a few host species, Diachasmimorpha longicaudata is a generalist that can survive within multiple genera of tephritid fruit fly hosts, including many globally important pest species. Diachasmimorpha longicaudata has therefore been widely released to suppress pest populations as part of biological control efforts in tropical and subtropical agricultural ecosystems. In this study, we investigated the role of a mutualistic poxvirus in shaping the host range of D. longicaudata across three genera of agricultural pest species: two of which are permissive hosts for D. longicaudata parasitism and one that is a nonpermissive host. We found that permissive hosts Ceratitis capitata and Bactrocera dorsalis were highly susceptible to manual virus injection, displaying rapid virus replication and abundant fly mortality. However, the nonpermissive host Zeugodacus cucurbitae largely overcame virus infection, exhibiting substantially lower mortality and no virus replication. Investigation of transcriptional dynamics during virus infection demonstrated hindered viral gene expression and limited changes in fly gene expression within the nonpermissive host compared with the permissive species, indicating that the host range of the viral symbiont may influence the host range of D. longicaudata wasps. These findings also reveal that viral symbiont activity may be a major contributor to the success of D. longicaudata as a generalist parasitoid species and a globally successful biological control agent.

Biological control of tephritid fruit flies Bactrocera spp. in Himachal Pradesh, India

Over the years, chemical-based insecticides have been used to enhance crop yield in the agricultural industry. However, the hazards associated with these insecticides have highlighted the need for an alternative method that is economical, eco-friendly, and safe. In this investigation, the efficacy of various biological materials, such as Neem kavach, Beauveria bassiana (Balsamo), and clay, was evaluated against fruit flies under open field conditions. The results revealed that the highest infestation was recorded in the control (71.67 %), while the lowest infestation (25.67 %) was observed in the plot treated with B. bassiana (1.5 %). This was followed by Neem kavach-treated plot (4 %) with an infestation rate of 26.67 %, and the clay-treated plot (15 g/L) with an infestation rate of 38.67 %, after the third spray. The impact of these biological agents on cucumber yield was also evaluated. The highest yield, 9.36 kg/plot, was obtained from the B. bassiana-treated plot, followed by Neem kavach-treated plots with yields of 8.94 and 7.28 kg/plot, respectively. The lowest yield of 4.58 kg/plot was recovered in the untreated plots. These findings suggest that the application of these biological agents is highly effective, as they repel egg-laying (oviposition deterrence), thereby minimizing fruit infestation and maximizing yield profit.

Persistence of widespread moderate Spinosad resistance among wild melon fly (Zeugodacus cucurbitae) and oriental fruit fly (Bactrocera dorsalis) populations on the major Hawaiian islands.

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). 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. 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.

Survey of Pesticide Use between Mango Farmers Practicing Area-Wide Integrated Pest Management and Conventional Farming in West Java, Indonesia

Mango farmers in Indonesia rely heavily on pesticides to control a variety of pests and diseases, with tephritid fruit flies being a major pest of the crop. To reduce pesticide use, Area-Wide Integrated Pest Management (AW-IPM) to control fruit flies was trialed and introduced in 2015 and has now been successfully implemented in several districts in West Java, Indonesia. This study surveyed pesticide use in mango farms adopting AW-IPM and those practicing conventional pest control methods. Purposive and Snowball sampling methods were used to select and interview 83 mango farmers to assess farmers knowledge and practices of pesticide use between the two groups. The farmers surveyed consisted of those that have adopted AW-IPM of fruit flies and conventional farmers, meaning those that did not adopt AW-IPM. The results of the survey revealed that compared to conventional farmers, the AW-IPM farmers had a high level of knowledge of pesticides and most of them were aware of pesticide-related environmental risks and adopted better and safer practices. Overall, storage of pesticides within living areas was reported by 10% of respondents, and most respondents (75%) adopted unsafe practices when disposing of used pesticide containers, such as selling them to plastic waste collectors. Half of all the respondents reported and experienced at least one symptom of a pesticide-related health problems. This study contributes to a better understanding of potential pesticide exposure and risks to mango farmers in Indonesia. A pesticide management training program for the mango farming community is badly needed.

Complete mitochondrial genomes of Bactrocera (Bulladacus) cinnabaria and B. (Bactrocera) propinqua (Diptera: Tephritidae) and their phylogenetic relationships with other congeners

Bactrocera (Bulladacus) cinnabaria and B. (Bactrocera) propinqua are tephritid fruit flies of the subfamily Dacinae, tribe Dacini. The whole mitogenomes of these two species (first report for the subgenus Bulladacus) possess 37 genes (13 protein-coding genes – PCGs, 2 rRNA and 22 tRNA genes). The mitogenome of B. cinnabaria (15,225 bp) is shorter than that of B. propinqua (15,927 bp), mainly due to the smaller size of the control region and intergenic spacers in B. cinnabaria. Molecular phylogeny based on mitochondrial genes (mt-genes) reveals two clades of the genus Bactrocera: one comprising the subgenus Bactrocera and the other comprising the subgenera Bulladacus, Daculus, Tetradacus and unassigned Bactrocera sp. ‘yunnanensis’. The subgenera represented by two or more taxa are monophyletic. B. (Bulladacus) cinnabaria forms a sister group with the subgenus Tetradacus (B. minax and B. tsuneonis) and B. sp. ‘yunnanensis’, in a clade containing also the basal sister lineage of the subgenus Daculus (B. oleae and B. biguttula). B. propinqua forms a sister group with B. ritsemai and B. limbifera in a subclade containing also B. umbrosa, B. curvifera and B. moluccensis of the monophyletic subgenus Bactrocera. The present study supports the synonymy of B. ruiliensis with B. thailandica. It also shows a high genetic similarity between (a) B. melastomatos and B. rubigina, (b) B. papayae and B. philippinensis, (c) B. dorsalis and B. invadens, (d) B. tryoni and B. neohumeralis, and (e) B. cheni and B. tuberculata; and B. cheni is distinct from and not a synonym of B. tsuneonis or B. lombokensis.

DNA Barcoding of Economically Important Fruit Flies (Diptera: Tephritidae) from the Lower Gangetic Plains of Eastern India

The Lower Gangetic Plains are India's central horticultural crop production regions. Fruit flies (Diptera: Tephritidae) are a significant insect pest that significantly hinders the effective crop production of various commercially valuable fruit and vegetable crops. Therefore, rapid and precise species identification techniques are essential to controlling, managing, and quarantining these pests. Furthermore, reliably identifying fruit flies is exceedingly challenging due to their striking resemblances in morphological characters. In this work, we investigated the effectiveness of mitochondrial cytochrome c oxidase I (COI) gene sequences for identifying seven fruit fly species, involving only the genus Bactrocera from the lower Gangetic Plains in eastern India. The sequences of the studied species showed 99%–100% similarity with sequences from within and outside the country. COI barcodes were able to distinguish between species, with K2P intraspecific genetic divergences ranging from 0-1% and K2P interspecific genetic divergences ranging from 3.65-28.46%, thus maintaining a proper barcode gap. Phylogenetic analyses were performed, and the results showed moderate to high supported monophyly among species. Therefore, COI barcodes have proven a highly successful alternative for quickly identifying fruit flies. This is also the first account of molecular identification of the previously reported tephritid fruit flies infesting fruits and vegetables in eastern India's agriculturally important lower Gangetic Plains.

Understanding the movement and dispersal patterns of released Fopius arisanus (Hymenoptera: Braconidae) parasitoids in a papaya orchard.

Implementation of augmentative biological control requires estimates of parasitoid dispersal from the release point to determine appropriate release density, spacing, and timing. This study evaluated the movement patterns of Fopius arisanus Sonan (Hymenoptera: Braconidae) parasitoids, which have historically been used to control invasive tephritid fruit flies. The wasps were released from the central point, and dispersal was monitored over time using parasitism in sentinel fruit and trap captures at 40 points radiating out from the center (15-240 m). The releases were conducted 4 times during June, July, September, and November 2006. The data showed that there were large declines in dispersal by distance. Parasitism was greatest closest to the release point, within 30 m. Parasitism was also greatest within the first 24 h of the release. After 1 wk, parasitism decreased from 41% to 1.5% within 30 m. These data correlated strongly with trap capture data, which also showed that parasitoid movement favored the SE region of our release site, roughly corresponding to the overall prevailing winds. Wind speed, relative humidity, and temperature all affected parasitoid movement during our trial, indicating the complex environmental factors that can affect release success. This is the first report of dispersal metrics for F. arisanus. Our findings are in agreement with other similar studies on braconid movement generally and suggest that frequent, high-density releases are most effective since the dispersal of F. arisanus is limited and retention in the environment is low. We discuss our results in the context of international augmentative biological control release programs.

Shaping the Microbial Landscape: Parasitoid-Driven Modifications of Bactrocera dorsalis Microbiota

Koinobiont endoparasitoids regulate the physiology of their hosts through altering host immuno-metabolic responses, processes which function in tandem to shape the composition of the microbiota of these hosts. Here, we employed 16S rRNA and ITS amplicon sequencing to investigate whether parasitization by the parasitoid wasps, Diachasmimorpha longicaudata (Ashmaed) (Hymenoptera: Braconidae) and Psyttalia cosyrae (Wilkinson) (Hymenoptera: Braconidae), induces gut dysbiosis and differentially alter the gut microbial (bacteria and fungi) communities of an important horticultural pest, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). We further investigated the composition of bacterial communities of adult D. longicaudata and P. cosyrae to ascertain whether the adult parasitoids and parasitized host larvae share microbial taxa through transmission. We demonstrated that parasitism by D. longicaudata induced significant gut perturbations, resulting in the colonization and increased relative abundance of pathogenic gut bacteria. Some pathogenic bacteria like Stenotrophomonas and Morganella were detected in both the guts of D. longicaudata-parasitized B. dorsalis larvae and adult D. longicaudata wasps, suggesting a horizontal transfer of microbes from the parasitoid to the host. The bacterial community of P. cosyrae adult wasps was dominated by Arsenophonus nasoniae, whereas that of D. longicaudata adults was dominated by Paucibater spp. and Pseudomonas spp. Parasitization by either parasitoid wasp was associated with an overall reduction in fungal diversity and evenness. These findings indicate that unlike P. cosyrae which is avirulent to B. dorsalis, parasitization by D. longicaudata induces shifts in the gut bacteriome of B. dorsalis larvae to a pathobiont-dominated community. This mechanism possibly enhances its virulence against the pest, further supporting its candidacy as an effective biocontrol agent of this frugivorous tephritid fruit fly pest.

Insecticidal effect of new synthesized chalcone derivatives on Caribbean fruit fly, Anastrepha suspensa.

In this present study, new chalcone derivatives were synthesized from 4-aminoacetophenone, which were confirmed by spectroscopic methods. The toxic risks of chalcones to humans and the environment were investigated by a web-based platform called ADMETlab. With this program, the possible toxic effects of the compounds on liver, respiratory system, and eyes were evaluated. For the topical insecticidal activity, adult female Caribbean fruit fly, Anastrepha suspensa, was targeted. Results of the toxicity tests showed that chalcone derivatives are effective against female A.suspensa. Among the synthesized chalcones, 1-(4-cinnamoylphenyl)-3-(p-tolyl)urea (2) exhibited the greatest insecticidal activity, resulting in 73 % mortality at 100 µg/fly after 24 h, whereas other derivatives showed less than 30 % mortality. Our results demonstrate that insecticidal activity may be modulated by the presence of a certain phenyl ring in the structure of derivative 2 and, therefore, has potential for design of efficient chemicals for tephritid fruit fly management.