Melon Fly Research Articles

Bio-efficacy of poison baits against Melon fruit fly, Bactrocera cucurbitae (Coquillett) in the open cucumber field

Bio-efficacy of poison baits against Melon fruit fly, Bactrocera cucurbitae (Coquillett) in the open cucumber field

Effect of various treatments against melon fruit fly, Bactrocera cucurbitae (Tephritidae: Diptera) in bitter gourd (Momordica charantia L.)

Effect of various treatments against melon fruit fly, Bactrocera cucurbitae (Tephritidae: Diptera) in bitter gourd (Momordica charantia L.)

YOLO_MRC: A fast and lightweight model for real-time detection and individual counting of Tephritidae pests

Tephritidae pests severely affect the quality and safety of various melons, fruits and vegetable crops. However, many agricultural managers lack an adequate understanding of the level of pest occurrence, resulting in the misuse of pesticides, which ultimately leads to environmental pollution and economic loss. Therefore, real-time detection and counting of Tephritidae pests are important for timely pest spotting and control. This work helps quickly determine the distribution and abundance of pests in the current environment, thus providing data on pest conditions for agricultural management to optimize pesticide use. Nevertheless, the fast speed, high accuracy, and lightweight performance of real-time detection and counting are difficult to balance. To address this problem, based on the YOLOv8n model, this paper takes Bactrocera cucurbitae pests as the detection target and proposes a fast and lightweight real-time detection and individual counting model for Tephritidae pests, named YOLO_MRC. This paper introduces three key improvements: (1) Constructing a new module called Multicat into the neck network increases the focus on the detection target by incorporating an attention mechanism; (2) Reducing the original three detection heads to two and then adjusting their sizes to decrease the number of parameters in the network model; (3) Devising a novel module, C2flite, to enhance the deep feature extraction capability of the backbone network. According to the above points, this paper conducts ablation experiments to compare the performances of different models. Experiments showed that the Multicat module significantly offsets the large increase in GFLOPs and processing time caused by reducing the detection head and can further reduce the number of parameters and improve the accuracy when combined with the C2flite module. On our Bactrocera cucurbitae pest dataset, the mAP@0.5 of the YOLO_MRC model reached 99.3%. Simultaneously, as the number of parameters decreases by 63.68%, GFLOPs is reduced by 19.75%, and the processing time is shortened by 5%. To ensure the validity of the model, YOLO_MRC is compared with four excellent detection models by using manual counting results as the benchmark. YOLO_MRC achieves an average pest counting accuracy of 94%, demonstrating superior performance in terms of model size and processing time. To further explore the performance of YOLO_MRC in multiclass insect detection tasks, we choose the public dataset Pest_24_640 for comparison with four state-of-the-art models. YOLO_MRC achieves a 3.6 ms processing time and 70.4% accuracy with only a 2.4 MB model size, which demonstrates the potential of YOLO_MRC in multiclass pest detection.

Laboratory evaluation of interspecific mating between Zeugodacus fruit flies and Bactrocera dorsalis

AbstractThe 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.

Female melon fruit flies, Zeugodacus cucurbitae, are attracted to a synthetic chemical blend based on male epicuticular components

The melon fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), is considered to be the most destructive pest of melons and other related cucurbit crops worldwide. Despite the potential of behaviour-based control strategies, little is known about the mechanisms involved in female mate choice. Herein, we investigated the production and chemoreception of cuticular hydrocarbons in both sexes of Z. cucurbitae, and the behavioural responses they induce. We studied the epicuticular composition of virgin males and females, using two-dimensional gas chromatography coupled with mass spectrometric detection. Data were interpreted using multivariate factorial analysis. The differentiation of chemical profiles was consistently observed over time. In young individuals, the chemical profiles did not differ between sexes, while sex-specific differences were noted in mature flies. The fly olfactory sensitivity to these compounds was explored using gas chromatography combined with chopped triple electroantennography and electropalpography detectors. This extensive exploration of the pest olfactory sensitivity highlighted three compounds produced by the male. When blended, they induced a robust positive response in unmated naive females in a six-choice olfactometer. The responsiveness of other Tephritidae species (a polyphagous species Bactrocera dorsalis (Hendel) and the cucurbit specialist Dacus demmerezi (Bezzi)) to whole body extracts of Z. cucurbitae was also investigated. Our findings showed that Z. cucurbitae uses species-specific olfactory receptors to detect male produced compounds. In addition, the palps were sensitive to a female-specific component, 1,7-dioxaspiro[5.5]undecane, which the males produce in minute quantities. Overall, this study provides a starting point for a pheromone-based tephritid lure that targets unmated females. The potential implications for pest management are discussed.

An Effective Melon Fly Control Strategy Based on Disinfection and Soil Productivity Management

The research employs both the literature and experimental data in order to develop reasonable strategies for melon fly control. The objects of research were sierozem soils of the Zhanakorgan region (Kyzylorda region), bentonite clays of the Sauran region (Turkestan region), and vermicompost obtained at the production site of the Research Institute “Ecology” at the International Kazakh-Turkish University, named after Khoja Ahmed Yasawi. The competitive agent ‘Vermiserbent’ was developed by combining sulphur-perlite-containing waste (SPCW), vermicompost, and natural bentonite clay. When incorporated into the soil, it serves as both an insecticide and a fertiliser recovery agent. The disinfection and enrichment of barren Sierozem soils in southern Kazakhstan could provide an eco-friendly approach to protect cucurbits (melon, watermelon, and pumpkin) against the melon fly. The average yield of watermelon treated with Vermiserbent increased by 2.3 t/ha compared to the control, melon by 4.6 t/ha, and pumpkin by 5.6 t/ha. The marketability of gourds as watermelons and melons after treatment with fertiliser increased by 1.2 times, and pumpkin by 1.1 times. The findings of studies conducted in agricultural fields in the Turkestan and Kyzylorda regions have shown that it is possible to produce environmentally sound gourds using a mixture of vermicompost, bentonite, and SPCW.

Seasonal Occurrence of Melon Fruit Flies (Zeugodacus cucurbitae Coq.) and Its Natural Enemies on Bitter Gourd

Aim: To study the seasonal occurrence of cucurbit melon fly and correlation study with weather parameters to know the impact of abiotic environmental factors on the activity of melon fruit fly concerning infesting the fruits of bitter gourd in crop ecosystem.
 Place and Duration of Study: College of Agriculture, VNMKV Parbhani, Maharashtra. Studies during two seasons Rainy and Summer 2021 and 2022 respectively.
 Methodology: The experimental plot was kept unsprayed throughout the crop season. The observation was recorded as soon as the incidence was noticed from five randomly selected plants at weekly intervals. The observations of fruit flies were recorded from the day of fruit formation to the last picking of the fruit. The damaged and healthy fruits were recorded at eachpicking to knowing the percentage fruit infestation by fruit flies.
 Results: Fruit fly was the major pest of bitter gourd in fruit damage. The fruit damage record range was 15.65 to 59.33 per cent in the rainy season whereas, 28.99 to 61.14 per cent in the summer season. The per cent fruit infestation shows a significant and positive correlation with no. of maggots per fruit (r = 0.857 and 0.905) during both seasons respectively. Weather parameters like morning relative humidity (MRH) and rainfall the during rainy season show significant and positive correlation (r = 0.87 and r = 0.71 respectively) whereas, during the summer season significant and positive correlation (r = 0.77) with MRH and significant and negatively correlated with (r = - 0.66) minimum temperature. The record of larval pupal parasitoid Psyttalia fletcheri (Silvestri) and it was discovered that 16% of the population was parasitized during the experimental period
 Conclusion: The infestation may vary from season to season, region to region and concerning variety also. Here the infestation range was higher during the summer season, which may be because of the coincidence with the fruit season of mango in that area.

RNA virus diversity in three parasitoid wasps of tephritid flies: insights from novel and known species.

Parasitoid wasps are a diverse group of parasitoid insects that play a crucial role in biological control and integrated pest management programs due to their wide range of host species and complex behaviors. Previous studies have reported that select RNA viruses in parasitoid wasps can affect either the host-parasitoid wasp or the pest host parasitized by the wasps. Therefore, a study of the dynamics of RNA viruses in parasitoid wasps is essential for artificial breeding programs and improving their parasitic capabilities. In this study, we detected the presence of nine novel and three known RNA viruses with complete genomes in three parasitoid wasp species: Diachasmimorpha longicaudata, Fopius arisanus, and Spalangia endius. These wasps are parasitoids that can parasitel tephritid flies, one of the most important pest groups of fruits and vegetables. In D. longicaudata, the small RNAs derived from the viruses exhibited distinct peaks at 22 nt and were symmetrically distributed across the viral genome. These findings indicate that these viruses can activate the host's RNAi immune response. PCR detection further revealed that DlNaLV efficiently infects female individuals of D. longicaudata with 100% efficiency, and ZcNLV is capable of infecting both D. longicaudata and its host, Zeugodacus cucurbitae. Our findings contribute to a better understanding of RNA viruses in parasitoid wasps and lay the foundation for future research on the triple-level trophic relationships between tephritid flies, parasitoid wasps, and RNA viruses.IMPORTANCEParasitoid wasp populations have developed persistent beneficial symbiotic relationships with several viruses through repeated evolution. However, there have been limited reports on RNA viruses in parasitoid wasps of tephritid flies, a significant pest group affecting fruits and vegetables. This study explores the diversity of RNA viruses in three parasitoid wasps of tephritid flies and highlights the potential biological significance of specific viruses in Diachasmimorpha longicaudata. These findings have important implications for the development of sustainable pest management strategies and the enhancement of artificial rearing techniques for parasitoid wasps.

Field Evaluation of Protein Bait in Attracting the Melon Fruit Fly <i>Zeugodacus cucurbitae</i> (Coquillett) in Snake Gourd

In India, melon fruit fly Zeugodacus cucurbitae Coquillett is a destructive insect pest of cucurbits. This study evaluated its attraction towards gel protein bait, an improvised version of liquid protein bait, found to be attractive in previous studies in snake gourd. Two field experiments were conducted for four months each (preliminary one - January to April, 2023; and confirmatory one - April to July, 2023). In early fruiting and fruiting stages, gel protein bait significantly attracted more females than the liquid protein bait; as regards male, cuelure trap attracted more followed by gel protein and liquid protein bait traps. Evaporation of gel protein bait in the field conditions was comparatively less from that of liquid protein bait.

Embryonic microinjection of ribonucleoprotein complex (Cas9+sgRNA) of whitegene in melon fly, Zeugodacuscucurbitae (Coquillett) (Diptera: Tephritidae) produced whiteeye phenotype.

Melon fly, Zeugodacus cucurbitae (Coquillett) is a major pest of cucurbitaceous crops, and causes substantial yield losses and economic costs. CRISPR/Cas9 is a rapid and effective site-specific genome editing tool for the generation of genetic changes that are stable and heritable. The CRISPR/Cas9 tool uses synthetically designed single guide RNA (sgRNA) that is complementary to the target gene and guides the Cas9 enzyme to perform nuclease activity by making double-strand breaks in the target DNA sequences. This tool can be effectively exploited to improve traits critical for the management of insect pests by targeting specific genes encoding these traits without the need of extensive genetic information. The white gene is an important gene responsible for the transport of body pigment precursor molecules. In this study, we produced effective mutagenesis of the white gene of Z. cucurbitae using the CRISPR/Cas9 tool with double sgRNAto target multiple sites of white to increase the efficiency in the generation of frame-shift mutations resulting in the white eye phenotype in adults. This was achieved through embryonic microinjection of the ribonucleoprotein (RNP) complex in the pre-blastoderm embryo stage 1 h after embryo laying. Our success with the production of a white eye mutant fly by CRISPR/Cas9 mutagenesis is important for the research on gene function and protein-level modifications in melon fly and forms the basis for the development of new genetic control strategies such as precision guided sterile insect technique (pgSIT) for this pest of economic significance.

Seasonal Abundance of Melon Fruit Fly, Bactrocera cucurbitae (Coquillett) Infesting Cucumber in Relation to Abiotic Factors

The present investigation on seasonal abundance of melon fruit fly in relation to weather parameters was conducted in cucumber at the farmers field, Kharsad, Navsari, Gujarat using Nauroji Stonehouse fruit fly trap containing cue-lure baited wooden block during summer 2022. Studies on seasonal abundance revealed that in cucumber the activity of adults of B. cucurbitae commenced from 13th Standard Meteorological Week (SMW) i.e., 4th week of March and continued till 19th SMW (1st week of May) which ranged from 38.00 to 59.75 with an average of 45.11 male fruit flies per four traps while, the peak adult population was observed during 17th SMW i.e., 4th week of April (59.75 mean male fruit flies/4 traps). Moreover, adult population of melon fruit fly showed positive and significant correlation with maximum temperature and negative and significant correlation with morning relative humidity.

Growth inhibitory, immunosuppressive, cytotoxic, and genotoxic effects of γ-terpinene on Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae)

γ-Terpinene, a monoterpene widely present in essential oils of many medicinal and aromatic plants with numerous biological properties, was evaluated for its insecticidal activity against melon fruit fly, Zeugodacus cucurbitae (Coquillett). Different concentrations (5, 25, 125, 625, and 3125 ppm) of γ-terpinene along with control were fed to larvae of melon fly. The number of pupae formed and adults emerged declined significantly after treatment. Morphologically deformed adults and pupae were also observed. The developmental duration too prolonged in treated larvae. Food assimilated, mean relative growth rate, larval weight gain, and pupal weight also declined. In the larvae treated with LC30 and LC50 concentrations, there was a decline in the titers of phenoloxidase and total hemocyte count, and variations were observed in the differential hemocyte count, suggesting an immunosuppressive effect of γ-terpinene on melon fly. Both concentrations also led to an increase in the apoptotic and necrotic cells as well as decrease in the viable hemocytes in the circulating hemolymph of treated larvae. Comet parameters (tail length, % tail DNA, tail moment, and olive tail moment) of γ-terpinene fed larvae increased significantly. Given the observed effects of γ-terpinene on normal developmental and nutritional physiology, its immunosuppressive properties, and its potential for genome damage, it can be considered for incorporation into integrated pest management strategies for controlling Z. cucurbitae.

A novel protein‐based fruit fly trap in melon flies Bactrocera cucurbitae for effective pest control management

AbstractAgriculture remains a major source of subsistence for local communities in India. However, agricultural yield can be strongly affected by agricultural pest outbreaks. This can result in economic losses for small‐scale farmers who already experience socio‐economic challenges, such as lack of appropriate infrastructure and subsides. Sophisticated pest management techniques (e.g. sterile insect technique) are less accessible to small farmers in developing countries, and therefore, alternative cost‐effective approaches for pest management are needed. Here, we report our findings of a 3‐year field trial (2018–2020) in India, which was designed to test for the potential effectiveness of a novel, slow‐release formulation protein‐based trap, compared to standard Cuelure traps against melon flies Bactrocera cucurbitae (Diptera: Tephritidae). Protein‐bait traps can attract flies from both sexes (as opposed to male‐only, chemical traps), bearing the potential to have a greater long‐term impact on pest populations by decreasing future reproductive potential of trapped individuals. We found that, despite uneven sampling efforts, Cuelure had overall higher trapping performance, while protein‐bait traps, despite trapping at lower efficiency, were equally effective for trapping males and females. Simulations with our field data revealed that protein‐bait traps can have an ‘inclusive’ advantage by trapping females and thereby preventing future individuals. Overall, our study highlights the potential benefits of using this alternative trapping technique to supplement pest management in developing countries.

Insect Pests of Zucchini and their Natural Enemies

Zucchini (Cucurbita pepo L.) is a trending crop for every health enthusiast today. The market demands for quality zucchini, bearing the best shape and size, free from all blemishes have gone sky high recently. Nevertheless, this cucurbitaceous crop is susceptible to many pests and diseases during its growth period, including its post-harvest life, which bring down the yield both in terms of quality and quantity.The time and intensity of the incidence of the pest varies greatly with crop growth stages. Therefore, an investigation was carried out during 2021-2022, for studying the incidence of various insect pests’ of zucchini and their natural enemies under naturally ventilated polyhouse condition at the experimental farm of Department of Horticulture, Assam Agricultural University, Jorhat, Assam, India. Five insect pests viz., Aleurodicus dispersus Russell, Aphis gossypii Glover, Aulacophora foveicollis Lucus, Bactrocera cucurbitae Coquillett and Pseudodendrothrips species Niwa were found to be very active from October, 2021 till March, 2022. Among them, A. dispersus and A. gossypii caused viral infection (zucchini yellow vein mosaic) in the early vegetative stage whereas B. cucurbitae caused severe damage by distorting and malformation of fruits during the flowering and fruiting stage. Two predators, namely Coccinella transversalis F. and Coccinella septempunctata L. were abundant during the growing period which fed on these insect pests.

Knockdown of the ecdysone receptor disrupts development and causes mortality in the melon fly, Zeugodacus cucurbitae.

Cucurbits are important economic plants that are attacked by numerous pests, among which the melon fly Zeugodacus cucurbitae is extremely problematic. New sustainable pest control strategies are necessary to replace chemical insecticides that are harmful to the environment, human health and nontarget species. The RNA interference (RNAi) technology is one of the most promising tools due to high efficiency and species specificity. We developed an RNAi strategy targeting the ecdysone receptor (ECR) of Z. cucurbitae, which plays an important role in moulting and reproduction. We identified, described and isolated the ECR gene of Z. cucurbitae and measured its expression pattern across developmental stages and tissues. ZcECR knockdown via dsZcECR ingestion caused a significant larval mortality and abnormal phenotypes in pupae and adults. About 68% of larvae fed with a dsZcECR-treated diet failed to enter the pupal stage and died. In addition, ZcECR knockdown dramatically reduced pupal weight (by 3.24 mg on average) and fecundity (by about 23%). RNAi targeting the ECR gene is therefore a promising method to control Z. cucurbitae, paving the way for the development of novel sustainable and highly specific control strategies.

Gut bacterial population and community dynamics following adult emergence in pest tephritid fruit flies

Gut microbiota are important contributors to insect success. Host-microbe interactions are dynamic and can change as hosts age and/or encounter different environments. A turning point in these relationships the transition from immature to adult life stages, particularly for holometabolous insects where there is radical restructuring of the gut. Improved knowledge of population and community dynamics of gut microbiomes upon adult emergence inform drivers of community assembly and physiological aspects of host-microbe interactions. Here, we evaluated the bacterial communities of the pest tephritid species melon fly (Zeugodacus cucurbitae) and Medditeranean fruit fly (medfly, Ceratitis capitata) associated with the pupae life stage and timepoints immediately following adult eclosion. We used a combination of culturing to determine cultivatable bacterial titers, qPCR to determine 16S-rRNA SSU copy numbers, and 16S V4 sequencing to determine changes in communities. Both culturing and qPCR revealed that fly bacterial populations declined upon adult emergence by 10 to 100-fold followed by recovery within 24 h following eclosion. Titers reached ~ 107 CFUs (~ 108 16S rRNA copies) within a week post-emergence. We also observed concurrent changes in amplicon sequence variance (ASVs), where the ASV composition differed overtime for both melon fly and medfly adults at different timepoints. Medfly, in particular, had different microbiome compositions at each timepoint, indicating greater levels of variation before stabilization. These results demonstrate that tephritid microbiomes experience a period of flux following adult emergence, where both biomass and the makeup of the community undergoes dramatic shifts. The host-microbe dynamics we document suggest plasticity in the community and that there may be specific periods where the tephritid gut microbiome may be pliable to introduce and establish new microbial strains in the host.

Insecticidal potential of endophytic Streptomyces sp. against Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae) and biosafety evaluation

Fruit flies of Tephritidae family pose a serious threat to cultivation of fruits and vegetables across the world. Among them, melon fruit fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae) is a devastating pest of plants from Cucurbitaceae family. In a rising concern about the harmful effects associated with the use of chemical insecticides and development of resistance in pest insects, safer pest management strategies such as, use of biopesticides of microbial origin are being contemplated. Therefore, the present study aimed to evaluate the insecticidal potential of Streptomyces sp. SP5 protein extract against Z. cucurbitae. MTT assay, Ames mutagenicity, DNA nicking, and comet assay were conducted to determine the biosafety of protein extract. Second instar larvae of Z. cucurbitae were treated with various concentrations (1, 100, 200, 300, 400, and 500 μg/ml) of Streptomyces sp. SP5 protein extract. The protein extract showed significant larvicidal effects with LC50 value of 308.92 μg/ml. The percentage of adults emerged declined with increase in concentration. There was significant prolongation in developmental durations of the larvae. Various morphological aberrations in the form of deformed adults and pupae and decline in pupal weight were also observed. The nutritional physiology of the treated larvae was also adversely affected. The results from biosafety evaluation revealed antimutagenic and non-toxic nature of Streptomyces sp. proteins. This study indicates that Streptomyces sp. SP5 has the potential to be used as an ecologically safe biocontrol agent against Z. cucurbitae.

Immunomodulatory, cyto-genotoxic, and growth regulatory effects of nerolidol on melon fruit fly, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae)

Insects have evolved a robust immune system consisting of humoral and cellular branches and their orchestrated response enables insect to defend against exogenous stressors. Exploration of underlying immune mechanisms of insect pest under allelochemical stress can give us new insights on insect pest management. In this study, nerolidol, a plant sesquiterpene was evaluated for its insecticidal, growth regulatory, immunomodulatory, and cyto-genotoxic effects against melon fruit fly, Zeugodacus cucurbitae (Coquillett). First, second, and third instar larvae of Z. cucurbitae were fed on artificial diet containing different concentrations (5, 25, 125, 625, and 3125 ppm) of nerolidol. Results revealed a significant reduction in pupation and adult emergence as well as prolongation of developmental duration of treated larvae. Decline in growth indices showed remarkable growth inhibitory effects of nerolidol. Pupal weight and nutritional parameters viz. Larval weight gain, food assimilated, and mean relative growth rate declined after treatment. Immunological studies on second instar larvae depicted a drop in total hemocyte count and variations in proportions of plasmatocytes and granulocytes of LC30 and LC50 treated larvae. Phenoloxidase activity in nerolidol treated larvae initially increased but was suppressed after 72 h of treatment. The frequency of viable hemocytes decreased and that of apoptotic and necrotic hemocytes increased with both the lethal concentrations of nerolidol. Comet assay revealed a significant damage to DNA of hemocytes. The findings of the current study indicate that nerolidol exerts its insecticidal action through growth regulation, immunomodulation, and cyto-genotoxicity thus revealing its potential to be used as biopesticide against Z. cucurbitae.

Efficacy of Metarhizium anisopliae (Mechnikov) Sorokin ICIPE 69 against the melon fly Zeugodacus cucurbitae (Coquillett) infesting courgette (Cucurbita pepo L.) in field cages

AbstractEffective integrated pest management (IPM) of the melon fly Zeugodacus cucurbitae (Coquillett), a devastating pest threatening horticultural production in Africa, is urgently needed. In this study, a caged field experiment was implemented in Thika, Kenya to test the efficacy of Metarhizium anisopliae (Mechnikov) Sorokin ICIPE 69 for Z. cucurbitae control in courgette Cucurbita pepo L. Treatments included: (1) dry conidia of M. anisopliae ICIPE 69 applied in an autodissemination device (fungus); (2) dry conidia of M. anisopliae ICIPE 69 in an autodissemination device combined with cuelure, a male attractant (fungus + cuelure); (3) a commercial insecticide (profenofos + cypermethrin) (insecticide); and (4) an untreated control (control). Each treatment was replicated thrice and the experiment was conducted twice during two seasons. Flies (300/tunnel) and treatments were introduced at flowering. One day later, 25 flies/tunnel were randomly collected from each cage to assess conidial acquisition (for fungus and fungus + cuelure treatments only) and mortality during a 10‐day interval in the laboratory. Flies in the fungus + cuelure treatment acquired more conidia (18.02 ± 0.48 conidia/fly) than those in the fungus treatment (11.93 ± 0.40 conidia/fly). Flies in the fungus + cuelure treatment experienced the highest mortality (95.31% ± 1.69%), while those in the insecticide treatment experienced the lowest (38.70% ± 4.32%). Dry conidia were collected from the autodissemination devices (in the fungus and fungus + cuelure treatment) daily for 7 days after flowering to check for compatibility through germination tests. Percentage germination reduced over time from 86.45% ± 1.77% and 87.72% ± 1.71% on day 1 to 16.39% ± 2.11% and 42.76% ± 1.74% on day 7 (seasons 1 and 2, respectively). The yield was significantly different among treatments and was, across seasons, highest in the fungus + cuelure (6961 ± 550 kg/ha) and insecticide (7267 ± 352 kg/ha) treatments and lowest in the control treatment (2089 ± 155 kg/ha).

Effects of temperature on the fecundity and longevity of Zeugodacus cucurbitae (Coquillet) (Diptera: Tephritidae) on artificial diet

AbstractThe melon fruit fly, Zeugodacus cucurbitae (Coquillett), is an important polyphagous pest that damages to various agricultural crops, whose distribution has become global as a result of human activity. In this study, we investigated the fecundity, pre‐oviposition and oviposition periods, and the longevity of adult Z. cucurbitae at various constant temperatures ranging from 15 to 35.2°C. One newly emerged one virgin female and two males of Z. cucurbitae were used, and the longevity of both sexes and the fecundity of the females were examined daily. The longevity of female Z. cucurbitae ranged from 183.8 days at 15.0°C to 30.8 days at 35.2°C, and the maximum fecundity per female was 1204 eggs at 24.5°C. The lower development threshold (LDT) and thermal constant (K) of females were estimated as 14.8°C and 781.13 degree‐days, respectively. Female reproduction was modeled using a two‐phase oviposition model. Oviposition was estimated using females in the oviposition phase, which had a complete pre‐oviposition phase. The oviposition model consisted of two reproductive components (total fecundity and age‐specific cumulative oviposition rate during oviposition) and a survival component (age‐specific survival rate). The daily egg production of Z. cucurbitae was estimated in relation to adult age and temperature.