Melon Fly Research Articles

Proteinex Bait Gel Formulations Suitable for Increased Field Stability and Enhanced Trapping of Melon Fly (Zeugodacus cucurbitae) Coquilette

Cucurbit fruit fly, Zeugodacus cucurbitae is an important insect pest of cucurbits. Fruit flies consisted of over 250 species worldwide and its maggots damage fruit from inside and hence, insecticides remain practically ineffective. Trapping the adult flies through parapheromenes, protein and food based traps is the most common practice. The protein and food baits attract both sexes over the parapheromones and are more effective due to their attractiveness and comparatively less weathering under field conditions. Hence, the present study was undertaken to prepare gel based formulations of liquid proteinex bait to increase it’s trapping efficiency. The gelling agents viz., xanthan gum powder, gaur gum powder, pectin powder, carrageenan powder, sodium alginate and gum arabic powder were used to prepare gel formulations of liquid proteinex bait developed by us. Among them, pectin and xanthan gum powders turned the liquid proteinex bait to semi-liquid at very less concentrations thus making them economical to use. Pectin, guar gum and carrageenan powder gel formulations maintained semi-liquid to slightly thickened consistency up to 9th day after preparation of bait and is advantageous for stability under field conditions. Protein content of pectin and guar gum powder formulations are similar as liquid proteinex bait which contributes for more attraction. pH of pectin and guar gum powder gel formulations was higher than the liquid proteinex bait thus increasing their attractiveness. As viscosity of pectin and carrageenan powder formulations was close to liquid proteinex bait, acceptability of these baits closely follows that of liquid bait. Study concluded that pectin powder gel formulation of liquid proteinex bait was found to be ideal and economical to use in field conditions to attract both male and female fruit flies.

Enhancing the Trapping of Melon Fruit Fly, Zeugodacus cucurbitae Coquilette through Synergizing the Odour and Visual Cues

The melon fruit fly (Zeugodacus cucurbitae Coquillett) poses a significant threat to cucurbit crops with substantial yield losses and challenging sustainable vegetable production. This study systematically investigated efficient color-based visual cues for attracting melon flies and explored the synergistic effects of these visual cues in conjunction with odour cues. This study was conducted in Agricultural College and Research Institute, TNAU, Madurai during 2024. Our studies included investigations on preferred colour by melon fly through olfactometer & insect cage bioassays in no choice & multiple choice conditions. The additive effect of the preferred colour when combined with the fruit fly attractive odour cue was investigated under field conditions. For both male and female melon fruit flies, yellow colour (RBG coordinates - 255:255:0) consistently emerged as the most efficient visual cue followed by white (255:255:255) and red (255:0:0). Field trials also confirmed the attractiveness of yellow colour as it outperformed other colours. The visual cue, yellow colour and odour cue (synthetic blend of four fruit fly EAG active synthetic compounds in a known ratio) were combined and found to be synergistic as this fusing captured significantly more flies than the either cues alone. These results highlighted the yellow colour as the most attractive visual cue for melon flies and combining effective of visual cues with established odour attractant to greatly enhance the trapping efficiency. This integrated approach offers a promising strategy for the management of melon fly and reduction of reliance on chemical pesticides contributing to more sustainable pest control in cucurbit production. The findings have significant implications for pest management strategies, especially in regions facing melon fly infestations that threaten crop yields and export potential.

Optimizing the Luring Period of Protein and Food Baits for Melon Fly (Zeugodacus cucurbitae Coquilette) Management

Backgrounds: This study was carried out to determine the effective duration of protein and food baits in field traps for maximizing melon fruit fly captures. As protein and food baits trap both male and female fruit flies, employing these traps in field conditions is considered as a reliable alternate management strategy. Aim of the Work: Determination of trap placement periods in field conditions for maximum trap catches of melon fruit flies. Methodology: Olfactometer bioassays were conducted to assess the persistence of bait attractiveness. Changes in pH and protein content of baits were monitored over time. Results: Proteinex bait showed peak attraction between I–X days after preparation (DAP), while soybean bait was most effective from I–IX DAP. Tomato bait attracted the highest number of fruit flies at XII–XII DAP, and banana bait showed maximum attraction at I–VIII DAP. Protein baits had higher pH and protein content, correlating with their superior trap efficacy. Conclusion: For effective melon fly management, proteinex and soybean baits should be replaced every 10–12 days, tomato baits every 13 days, and banana baits every 8 days. The higher pH and protein content of protein baits contributed to their greater effectiveness, making them a valuable tool in sustainable pest control strategies.

Attraction of Bactrocera cucurbitae (Coquillett) to selected gut microbiota supernatants: implications for pest control.

Bactrocera cucurbitae (Coquillett) is a distructive quarantine insect pest that causes significant economic losses on cucurbit crops. To explore a green control approach, we investigated the behavioral responses of B. cucurbitae larvae and adults to bacterial suspensions, sediments, and supernatants derived from eight gut microbial strains across four distinct genera. The proboscis extension response was used to evaluate the impact of these microbial strains. In addition, using food selection experiments, two-choice trap methods, and gas chromatography-mass spectrometry, we isolated and identified the predominant volatile compounds in the microbiota supernatants. Among the tested gut microbial strains, Kluyvera, Morganella, and Providencia exhibited notable attraction toward B. cucurbitae. In particular, the supernatant of Providencia M38 revealed the most highly attractive effect on B. cucurbitae larvae, whereas the supernatant of Morganella M72 was highly attractive to B. cucurbitae adults. Primary components present in the supernatant of M38 and M72 were dimethyl disulfide, indole, 2-nonone, phenethyl alcohol, and 1-decanol. Strains of M38 and M72 displayed remarkable attractive properties for B. cucurbitae larvae and adults, respectively, presenting promising potential for developing a novel attractant for this pest species. © 2025 Society of Chemical Industry.

Deterministic and stochastic effects drive the gut microbial diversity in cucurbit-feeding fruit flies (Diptera, Tephritidae).

Insect diversity is closely linked to the evolution of phytophagy, with most phytophagous insects showing a strong degree of specialisation for specific host plants. Recent studies suggest that the insect gut microbiome might be crucial in facilitating the dietary (host plant) range. This requires the formation of stable insect-microbiome associations, but it remains largely unclear which processes govern the assembly of insect microbiomes. In this study, we investigated the role of deterministic and stochastic processes in shaping the assembly of the larval microbiome of three tephritid fruit fly species (Dacus bivittatus, D. ciliatus, Zeugodacus cucurbitae). We found that deterministic and stochastic processes play a considerable role in shaping the larval gut microbiome. We also identified 65 microbial ASVs (Amplicon sequence variants) that were associated with these flies, most belonging to the families Enterobacterales, Sphingobacterales, Pseudomonadales and Betaproteobacterales, and speculate about their relationship with cucurbit specialisation. Our data suggest that the larval gut microbiome assembly fits the "microbiome on a leash" model.

Deciphering the potential of plant metabolites as insecticides against melon fly (Zeugodacus cucurbitae): Exposing control alternatives to assure food security

Deciphering the potential of plant metabolites as insecticides against melon fly (Zeugodacus cucurbitae): Exposing control alternatives to assure food security

Olfactory response of melon fruit fly Zeugodacus cucurbitae (Coquillett) to protein bait volatiles

Olfactory response of melon fruit fly Zeugodacus cucurbitae (Coquillett) to protein bait volatiles

Assessing the efficiency of integrated pest management practices against fruitfly (Bactrocera cucurbitae) in snake gourd

The Present study was conducted to assess the efficiency of Integrated Pest Management practices with farmers practices of chemical control against fruitfly in snake gourd. The demonstration was conducted at farmers field in Irur village of the Perambalur District (Tamil Nadu) during Kharif season, 2019-20. The findings revealed that in IPM plot fruit fly infested fruit of 6.9 % with highest weight of healthy fruit of 229.7 q/ha and lowest infested fruit of 15.96 q/ha with more mean number of 42.90 no. adult fruit fly trapped in pheromone trap where as in farmers practices it was 15.8 Percent of infested fruit, healthy fruit of 126.46 q/ha and infested fruit of 21.41 q/ha respectively. The result revealed that the IPM practices was significantly effective in management of fruitfly damage in snake gourd plants and increased the yield with low cost of cultivation Rs.22052.5/ha with a benefit cost ratio of 4.19 whereas it was Rs. 24412.5/ha and 2.22 respectively in farmers practices.

Evaluation of the Sterile Insect Technique for the Control of the Melon Fly (Bactrocera cucurbitae) Under Laboratory and Semi-Field Conditions in Sri Lanka.

The melon fly, Bactrocera cucurbitae, poses a severe threat to the country's agricultural productivity, particularly in the cultivation of cucurbitaceous crops. This study was conducted to determine the ideal irradiation dose to be used to set up a Sterile Insect Technique (SIT)-based strategy to control B. cucurbitae outbreaks in Sri Lanka. A B. cucurbitae colony was established and maintained under standard laboratory conditions. Male pupae (100 pupae per treatment) were exposed to different radiation doses, namely 0 (control), 50, 60, 70, 80, 90, 100, and 110 Gy. The effect of irradiation on selected performance parameters such as survival, flight ability, fecundity, fertility, and adult longevity was evaluated under laboratory conditions. In addition, mating competitiveness was evaluated for irradiated male B. cucurbitae. Significant differences were observed in percentage pupal survival, flight ability, and fertility rates (p < 0.05) at a 95% level of confidence. Further, the 50% and 75% adult longevity periods of irradiated B. cucurbitae males significantly decreased with the increasing irradiation dosage (p < 0.05). B. cucurbitae exposed to 70 Gy radiation reported a mean pupal survival rate of 94.0 ± 1.25, flight ability of 93.3 ± 1.88, and fertility 0.2 ± 0.05%, along with a mean longevity of 38 ± 1.5 days until 50% reduction in the population. The competitiveness of B. cucurbitae exposed to 70 Gy with respect to wild males was 0.56 under laboratory conditions, which reduced up to 0.5 in semi-field settings. The 70 Gy dose could be recommended as the optimal radiation dose for the production of sterile B. cucurbitae males with an acceptable level of fitness and sterility to be used in SIT-based melon fly control programmes in Sri Lanka.

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.

A new genome sequence resource for five invasive fruit flies of agricultural concern: Ceratitis capitata, C. quilicii, C. rosa, Zeugodacus cucurbitae and Bactrocera zonata (Diptera, Tephritidae)

Here, we present novel high quality genome assemblies for five invasive tephritid species of agricultural concern: Ceratitis capitata, C. quilicii, C. rosa, Zeugodacus cucurbitae and Bactrocera zonata (read depths between 65 and 78x). Three assemblies (C. capitata, C. quilicii and Z. cucurbitae) were scaffolded with chromosome conformation data and annotated using RNAseq reads. For some species this is the first reference genome available (B. zonata, C. quilicii and C. rosa), for others we have published improved annotated genomes (C. capitata and Z. cucurbitae). Together, the new references provide an important resource to advance research on genetic techniques for population control, develop rapid species identification methods, and explore eco-evolutionary studies.

ZcGSTe1 regulates oxidative stress during vitellogenesis in Zeugodacus cucurbitae

ZcGSTe1 regulates oxidative stress during vitellogenesis in Zeugodacus cucurbitae

Evidence for a gut microbial community conferring adaptability to diet quality and temperature stressors in phytophagous insects: the melon fruit fly Zeugodacus cucurbitae (Diptera: Tephritidae) as a case study

BackgroundThe high invasiveness of phytophagous insects is related to their adaptability to various environments, that can be influenced by their associated microbial community. Microbial symbionts are known to play a key role in the biology, ecology, and evolution of phytophagous insects, but their abundance and diversity are suggested to be influenced by environmental stressors. In this work, using 16 S rRNA metabarcoding we aim to verify (1) if laboratory rearing affects microbial symbiont communities of Zeugodacus cucurbitae females, a cosmopolitan pest of cucurbitaceous crops (2) if temperature, diet quality, and antibiotic treatments affect microbial symbiont communities of both laboratory and wild populations, and (3) if changes in microbial symbiont communities due to temperature, diet and antibiotic affect longevity and fecundity of Z. cucurbitae.ResultsThe results showed that microbial diversity, particularly the β-diversity was significantly affected by insect origin, temperature, diet quality, and antibiotic treatment. The alteration of gut microbial symbionts, specifically Enterobacteriaceae, was associated with low fecundity and longevity of Z. cucurbitae females feeding on optimal diet only. Fecundity reduction in antibiotic treated females was more pronounced when flies were fed on a poor diet without protein.Conclusionsour study proves the relationship between gut microbiome and host fitness under thermal and diet fluctuation highlighting the importance of microbial community in the adaptation of Z. cucurbitae to environmental stress.Clinical trial numberNot applicable.

Knockdown of the ZcVgR Gene Alters the Expression of Genes Related to Reproduction and Lifespan in Zeugodacus cucurbitae (Coquillett) Under Extreme Heat Conditions.

Zeugodacus cucurbitae (Coquillett) is an important migratory vegetable pest. Previous research has demonstrated that short-term high temperatures induce differential expression of the vitellogenin receptor (ZcVgR) gene, reducing the number of eggs laid and the lifespan of female Z. cucurbitae. In this paper, we used Tandem Mass Tags (TMT) quantitative proteomics and Illumina high-throughput sequencing to determine the proteomic and transcriptomic information of female Z. cucurbitae after siRNA-mediated silencing of the target gene (ZcVgR) to gain a comprehensive understanding of the molecular mechanism of this gene in the regulation of reproduction and lifespan. The findings demonstrated that following the target gene's silencing, the ZcVgR gene's transcriptional expression was significantly downregulated, and there was no significant difference in protein level. The transcriptome and proteome had a low correlation; when the ZcVgR gene was silenced, vitellogenin-1 (ZcVg1), juvenile hormone epoxide hydrolase (JHEH), troponin C (TnC), heat shock protein 70 (HSP70), and other related genes were downregulated at the transcriptional level. By silencing the ZcVgR gene, transcriptionally level immune-related pathways were activated and energy metabolism-related pathways were inhibited; protein-level glycometabolism and phagosome pathways were activated, while phototransduction-fly and autophagy-animal pathways were inhibited. The findings of this study might offer a theoretical foundation for integrated management of Z. cucurbitae in the summertime.

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.

MiR-318-3p targets leucine carboxyl methyltransferase in ovary and impacts female fertility in Zeugodacus cucurbitae

miR-318-3p targets leucine carboxyl methyltransferase in ovary and impacts female fertility in Zeugodacus cucurbitae

Deterrence and behavioral mode of coconut oil-derived free fatty acids on Zeugodacus cucurbitae oviposition.

Previous studies have shown oviposition deterring properties of 8 coconut free fatty acid (CFFA) compounds on fruit flies with different key deterrent components for different species. Here we evaluated oviposition deterrence of CFFA using laboratory 2-choice bioassays against Zeugodacus cucurbitae, determined key-bioactive deterrent compounds, and evaluated their behavioral mode. Unlike other reported fruit fly species, CFFA mixture increased Z. cucurbitae oviposition when directly applied on an oviposition substrate. When tested individually in subsequent tests, 4 compounds (caprylic, capric, oleic, and linoleic acids) significantly reduced the oviposition ("negative-compounds"), 1 compound (stearic acid) had no effect ("neutral-compound"), and 3 compounds (lauric, myristic, and palmitic acids) stimulated the oviposition ("positive-compounds"). The 4-component negative-compound blend was effective at reducing oviposition. However, adding stearic acid to the 4-component blend (5-component blend, 5c) further reduced oviposition. Adding any of the positive-compounds to the 5c resulted in loss of oviposition deterrence, suggesting the 5c as the key deterrent component blend. The blend was also effective in no-choice assays and when applied on cucumbers, a preferred host of Z. cucurbitae. When given a choice, Z. cucurbitae made 48.5% fewer visits, spent 39% less time, and oviposited 88.2% fewer eggs per min on 5c treated pumpkin agar than on control agar, suggesting that the 5c blend has both spatial repellency and contact deterrence. Given that all compounds are registered food additives and generally regarded as safe, this blend has potential application in behavioral control strategies, such as push-pull, to protect host fruit against Z. cucurbitae.

Adult dietary experience influences mortality of the pest melon fly, Zeugodacus cucurbitae (Diptera: Tephritidae), to an ingested toxin

AbstractIngested toxins formulated as baits can be effective in the management of insect pests, but their efficacy may be influenced by insect foraging alongside active ingredients. There are several components that might influence insect consumption of toxic baits, one of which being prior nutritional exposure. In our study, we investigated how protein deprivation following adult emergence influences lethal and sublethal effects of boric acid on the pest tephritid melon fly, Zeugodacus cucurbitae. We performed a series of experiments to address the impact of prior diet on mortality, diet consumption, enzymes involved in detoxification and antioxidation and fly activity. Newly emerged melon fly adults were provided either diet containing 3:1 sucrose/yeast hyrdrolysate or just sucrose for three days prior to bioassays. Overall, protein deprivation had a strong effect on fly interactions with boric acid. In two separate experiments (continuous exposure and short duration feeding), insects only pre‐fed sucrose had significantly higher mortality compared with those pre‐fed protein. Insects that were pre‐fed only sucrose removed more liquid diet over the same duration of the experiments, suggesting compensatory foraging behaviours. Adults pre‐fed sucrose had higher catalase (1.5×) and superoxide dismutase (1.7×) activities compared with adults pre‐fed sucrose‐yeast, but we found no effect of boric acid on their activity or that of glutathione‐S‐transferase or acetylcholinesterase activity. Boric acid consumption also significantly reduced the activity of melon flies. Overall, our results demonstrate that prior diet in fly adulthood can impact subsequent exposure to and efficacy of ingested toxicants.

Evaluation of Efficacy of Certain Pesticides and Black Plastic Mulch as an Approach of Developing Integrated Pest Management for Melon Fruit Fly (Bactrocera cucurbitae)

A field experiment was conducted at Pyuthan Municipality, Pyuthan district of the Federal Democratic Republic of Nepal to develop an integrated pest management strategy against melon fruit fly (Bactrocera cucurbitae). The experiment was laid out in two factorial Randomized Complete Block Design (RCBD). The first factor was different doses of pesticides; Spinosad (45% SC) @ 1ml/3l water, Cypermethrin (10% EC) @5ml/20l water and, botanical Jholmol @ 1:3 ratio (1 part Jholmol and 3 part water). The second factor was Black plastic mulch and no mulch. The pesticides were applied at 9 day intervals and data on fruit infestation, ovary damage, yield and, post-set damage were collected at 3 day intervals and the data analysed using R Studio. The result revealed highly significant differences among mulching and non-mulching plots. Mulching plots had the lowest fruit infestation (3.95%), lowest ovary damage (0.88%), lowest post-set damage (2.38%) and, higher yield per plot (21.25 kg) than non-mulched plots. Highest protection against melon fruit fly was observed by Spinosad at the third spray; percentage of fruit infestation (3.71%), ovary damage (0.76%) and yield (20.20 kg/plot) followed by Cypermethrin and Jholmol. The highest protection was obtained by the application of Cypermethrin (1.78%) at the post-set stage followed by Spinosad and Jholmol. The application of Spinosad, Cypermethrin alone with black plastic mulch provided superior protection than Jholmol and control. However, the pest reduction and yield observed on the treatments with the combination of Jholmol and black plastic mulch was satisfactory (21.87 kg/ha) than control (14.58 kg/ha). Int. J. Appl. Sci. Biotechnol. Vol 12(3): 126-136.

An effective dosage of neem (Azadirachta indica Juss) and aloe vera (Aloe barbadensis Miller) extracts against adult aphid (Myzus persicae Sulzer) and melon flies (Bactrocera cucurbitae Coquillet)

The objective of the study was to evaluate the efficaciousness dosage of aqueous extracts of neem (Azadirachta indica Juss) and aloe vera (Aloe barbadensis Miller) at different concentrations (40%, 60%, and 80%) against adult melon flies (Bactrocera cucurbitae Coquillet) and aphids (Myzus persicae Sulzer) in laboratory conditions. The experiments were designed and conducted from April to June 2023 at Sokoine University of Agriculture, Tanzania. The study found that as extract concentrations increased, there was a noticeable drop in insect survival. The dosage of 80% at 48 hours and 60% at 72 hours were observed to perform better as few were observed to survive. At the highest dosage of 80% and 60%, extracts from neem and aloe vera both resulted to 100% insect mortality. The results highlight the potential of aloe vera and neem extracts to have a positive effect on insect pest management rather than untreated crops.