Fruit Fly Populations Research Articles

Fruit flies (Diptera: Teprithidae) and their parasitoid (Hymenoptera: Braconidae) species from registered snake fruit production during early rainy and dry seasons in the Special Region of Yogyakarta, Indonesia

Exportation of snake fruit from Indonesia to China, Australia, and New Zealand has been hindered due to fruit fly infestations (Diptera: Teprithidae). The goal of this study was to identify fruit flies and their parasitoid species from registered snake fruit productions in Turi, Sleman, that have reached packaging houses during early rainy and dry seasons. Fruit fly species were morphologically identified from collected rejected or damaged snake fruit. Parasitization was calculated by dividing the number of emerging parasitoid species by the total number of parasitoid and fruit fly individuals. The population of fruit flies and parasitoids was then compared to climatic data. Female fruit flies that emerged from snake fruit possessed spots on their front preapical femur, concluding that these species were Bactrocera carambolae. The average fruit fly that emerged per fruit was 16.5 individuals. Only one parasitoid species emerged and possessed notauli on mesonotum that elongated to the center and petiole and longitudinal metasomal tergum 2, implying that this parasitoid species was Fopius arisanus with an average population of 5.71 individuals with a parasitization percentage of 26.86%. Results from this research concluded that the fruit fly species collected from registered snake fruit productions in Turi, Sleman, during the early rainy season and dry season was Bactrocera carambolae with a low parasitization level by Fopius arisanus. This parasitization level may be affected by fruit fly density and climatic factors, such as humidity and rainfall.

Winter fleshy‐fruited plants are the catalysts for spring populations of an invasive fruit fly

Winter fleshy‐fruited plants are the catalysts for spring populations of an invasive fruit fly

Evaluating the Efficacy of the Male Annihilation Technique in Managing Oriental Fruit Fly (Diptera: Tephritidae) Populations through Microscopic Assessment of Female Spermathecae.

The male annihilation technique (MAT) plays a crucial role in the pest management program of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). However, a suitable method for real-time and accurate assessment of MAT's control efficiency has not been established. Laboratory investigations found that motile sperms can be observed clearly under the microscope when the spermathecae dissected from mated females were torn, and no sperms were found in the spermathecae of virgin females. Furthermore, it was confirmed that sperms can be preserved in the spermathecae for more than 50 days once females have mated. Laboratory results also indicated that proportion of mated females decreased from 100% to 2% when the sex ratio (♀:♂) was increased from 1:1 to 100:1. Further observation revealed that there were no significant differences in the superficial area of the ovary or spermatheca between mated females and virgin females. Field investigations revealed that the proportion of mated females (PMF) could reach 81.2% in abandoned mango orchards, whereas the PMF was less than 36.4% in mango orchards where MAT was applied. This indicates that the PMF of the field population can be determined by examining the presence of sperms in the spermathecae. Therefore, we suggest that this method can be used to monitor the control efficiency when MAT is used in the field.

Efficacy of Biopesticides for controlling major pests of Cucumber (Cucumis sativus L.) in Surkhet District, Nepal

This study evaluated the efficacy of biopesticides against major insect pests of cucumber (Cucumis sativus L.) in Lekbeshi, Surkhet, Nepal. A randomized complete block design experiment was conducted with four treatments: Beauveria bassiana (1 ml/L), Bacillus thuringiensis (Bt) (2 ml/L), Jholmol (1:5 concentration), and an untreated control. After the third spray, B. bassiana reduced red pumpkin beetle populations from 1.4 to 0.4 insects per plant, while Bt reduced fruit fly populations from 2.8 to 1.6 insects per plant, compared to the control (4.2 to 2.2). At 60 days after transplanting, Bt-treated plants were significantly taller (137.45 cm) than control plants (111.28 cm). Fruit damage was lowest in Bt-treated plots (1.8% and 0.69 kg damage weight) compared to the control (3.8% and 0.69 kg). While yield attributes showed no significant differences, total yield was highest in B. bassiana-treated plots (35.58 t/ha) compared to the control (17.8 t/ha). Economic analysis revealed that B. bassiana treatment had the highest benefit-cost ratio (4.19), followed by Bt (2.9), control (2.8), and Jholmol (2.3). These findings suggest that biopesticides, particularly B. bassiana and Bt, can effectively manage major cucumber pests while improving yield and economic returns, offering a sustainable alternative to chemical pesticides in subtropical regions.

REFUGIA BLOG TO INCREASE THE DIVERSITY OF NATURAL ENEMIES THAT FUNCTION AS CONTROL OF FRUIT FLY PESTS BACTROCERA DORSALIS IN MALANG ORANGE GROVES IN MALANG ORANGE GROVES GARDEN

Bactrocera dorsalis is a pest that attacks horticultural fruit crops, especially oranges. Control of fruit fly pests can be done by engineering the blog refugia habitat which attracts the presence of natural enemies so that it can stabilize the ecosystem and be more sustainable for the environment. The aim of this research is toanalyzing the application of habitat engineering to the Bactrocera dorsalis fruit fly population and natural enemy diversity, fruit fly population fluctuations, and Farmers' perceptions of pest controlfruit flies that attack oranges. This research was conducted on former rice fields and moorland in Krajan Hamlet, Sumbersekar Village, Dau District, Malang Regency. The method used was survey sampling by placing refugia plants in tumpeng sari, 4 fruit fly traps were placed in each field, the trapped fruit flies and natural enemies were observed every morning, afternoon and evening every week 10 times. The results showed an increase in the diversity of natural enemies in the 2 fields planted with refugia, abiotic factors and host plants influenced fluctuations in fruit fly populations. In orange orchards, 2 rainfall factors influence the rise and fall of fruit fly populations. Farmers' perceptions are relatively high in their approval of controlling fruit fly pests using refugia plants which has been proven through validity and reliability tests on the results of the questionnaire.

Fruit Fly (Diptera: Tephritidae) Populations on Same Fruit Crops in Sumuri District, Bintuni Bay

Most of the people of Sumuri District make a living as farmers, especially fruit and vegetable farmers. Local fruit plants that are commonly cultivated include bananas, papaya, mangoes, oranges, rambutan, pineapple and water guava. One of the obstacles experienced by the community is the presence of pests that attack the fruit, causing poor fruit and even crop failure. This prompted a field survey of fruit flies in community fruit plantations. The field survey was conducted in October-December 2023 in Tofoi Village, Materabu Jaya Village and Forada Village, Sumuri District, Bintuni Bay. The survey was conducted using the trapping method with Steiner model traps that have been modified from mineral water bottles and the addition of native fruit samples and Methyl Eugenol (ME) with petrogenol trademark. Traps were set for three days and then identification and collection of fruit fly samples were carried out. The results showed that the highest population of fruit flies was in pineapple (Annanas commosus), which was 738 and the least in water guava (Syzygeum aqueum), which was 324. There were nine fruit fly species identified from this study, including: Bactrocera umbrosa (Fabricus), B.carambolae (Drew and Hancock), B.dorsalis (Hendel), B.curreyi (Drew), B.curvifera (Walker), B.emittens (Walker), B.papayae (Drew and Hancock), B.tryoni (Froggatt) and Procecidochares connexa (Macquart)

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.

Toxicity of several insecticides against fruit flies Bactrocera dorsalis (Hendel) and Bactrocera carambolae (Drew and Hancock) (Diptera: Tephritidae) in the laboratory

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

Comparative Responses of Two Major Cucurbit Pests, Zeugodacus cucurbitae and Zeugodacus tau to Phenylbutanoid Male Lures.

Zeugodacus cucurbitae and Z. tau are two major fruit fly pests of cucurbitaceous plants in the tropical and subtropical regions. The former species has a broader host range and wider world distribution than the latter. With global climate change, Z. tau shows great potential for geographical expansion with several invasion records in recent years. Males of both species are attracted to cue lure (CL) (and raspberry ketone (RK), a deacetyl derivative of CL), a common male lure used in fruit fly population detection, monitoring and control programs. Males of both species are also known to respond to zingerone (ZN), which are produced by some rainforest orchids. Previous studies have shown that fruit fly-male lure interactions are unique to species and lure types, and significantly impact the success of a lure-based fruit fly control program. We seek to compare the attraction of Z. cucurbitae and Z. tau males to CL, RK and ZN via Probit behavioral assays. Our results showed that CL is more attractive to Z. cucurbitae and Z. tau males than RK, while ZN is a poor lure for both species. Attraction Z. tau to CL is slightly lower than Z. cucurbitae, but the former is at least 1.71 times less attractive to RK than the latter. Together with published information on species' sexual development, our current study indicates a lure-based control program via male annihilation technique for Z. tau will be more challenging than Z. cucurbitae and should incorporate other integrated pest management strategies for a desirable outcome.

Adapting to climate disparities: Implications for fruit fly populations in citrus orchards

In the context of climate change, the agricultural sector faces the imperative of devising adaptive strategies to mitigate emerging challenges. This study aimed to know the relationship between climatic disparities and fruit fly populations in citrus orchards. Utilizing Steiner trap and Methyl Eugenol wooden blocks as monitoring, male annihilation controlling devices, and spraying protein bait, we conducted a comprehensive investigation across two distinct agroclimatic conditions. The main variations were monthly rainfall (mm), accentuating diverse agroclimatic dynamics. Surprisingly, an analysis comparing low rainfall (1-4 mm) to moderate rainfall (14-21 mm) periods did not affect fruit fly populations. Contrary to conventional assumptions, variations in only precipitation did not significantly impact fruit fly population dynamics. The critical factors were the dominant role of host plant availability and the efficacy of pest management practices in steering population trends. This study showed that climatic factors contribute to pest dynamics; however, they might not function as a single change factor. Instead, host plant availability and the implementation of effective pest control interventions held more significant influence. Based on the interconnected relationship between climate and pests, amid a continuously developing climate scenario, more careful management strategies are needed to increase the sustainability of citrus yields for food security and farmer welfare.

Influence of weather parameters on the population of Bactrocera spp. (Diptera, Tephritidae) in the mango orchards of Padanakkad, Kerala, India

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

Mediterranean fruit fly population phenological patterns are strongly affected by elevation and host presence

The Mediterranean fruit fly (medfly) (Ceratitis capitata, Diptera: Tephritidae), is an extremely polyphagous pest that threatens the fruit production and trading industry worldwide. Monitoring C. capitata populations and analysing its dynamics and phenology is considered of outmost importance for designing and implementing sound management approaches. The aim of this study was to investigate the factors regulating the population dynamics of the C. capitata in a coastal and semi-mountainous area. We focused on effects of topography (e.g. elevation), host presence and seasonal patterns of ripening on the phenological patterns considering data collected in 2008. The experimental area is characterized by mixed fruit orchards, and Mediterranean climate with mild winters. Two trap types were used for population monitoring. The female targeted McPhail type and the male targeted Jackson type. Traps were placed in farms located at different elevations and landscape morphology (coastal and semi-mountainous areas). The main crops included citrus, apples, peaches, plums, pears, figs, quinces and apricots. Adult captures were first recorded in May, peaked in mid-summer and mid-autumn and almost ceased at the end of the season (January 2008). Captures in the coastal areas preceded that of highlands by 15 days. Most of the adults detected during the fruit ripening of late stone fruit cultivars (first peak) and citrus (second peak). The probability of capturing the first adults preceded almost three weeks the peak of adult captures either considering the elevation or host focus analyses. The results provide valuable information on the seasonal population trend of C. capitata in mixed fruit Mediterranean orchards and can support the set-up of IPM systems in areas with various landscapes and different hosts throughout the fruit growing season.

Susceptibility of Mangifera indica (Sapindales: Anacardiaceae) cultivars to fruit flies (Diptera: Tephritidae) in 2 agroecological zones of Cameroon.

The Sudano-Sahelian and the high Guinea savannahs agroecological zones of Cameroon are suitable for the full development of tree crops, including mango. Unfortunately, fresh fruits exported to local and international markets are frequently rejected due to the presence of fruit fly larvae (Diptera: Tephritidae), resulting in drastic income losses and overuse of chemical control products. To promote sustainable management strategies, a 2-yr study (2020-2021) was conducted in 4 and 3 mixed orchards, respectively. Attacked mangoes showing signs of fruit fly damage were collected and taken to the laboratory to rear and identify fruit flies. Repeated grafting and agroclimatic differences were responsible for dissimilarities between the 2 zones, with 18 and 16 cultivars, respectively. From 2,857 attacked mangoes, 26,707 fruit flies belonging to 4 species were identified: Bactrocera dorsalis, Ceratitis cosyra, Ceratitis fasciventris, and Ceratitis anonae. Climate change was the factor determining the distribution of the 2 most important mango fruit flies: B. dorsalis was a wetland species (dominance/occurrence > 70%), while C. cosyra was a dry-land species (dominance/occurrence > 75%). Both species were responsible for high levels of infestations. Bactrocera dorsalis preferred 3 mango cultivars, namely Palmer and Smith in Zone 1, and Ifack 1 in Zone 2 (infestation > 20 individuals/100g of mango). The host-plant spectrum of C. cosyra was modified by alternative host plants. Both C. fasciventris and C. anonae were rare. Findings from this study could guide researchers in the development of monitoring tools for fruit fly populations and, subsequently, in reducing the damage they cause to mangoes.

A spatio-temporal modelling approach to understand the effect of urban fruit fly outbreaks on peri-urban orchards

Urban areas are well-known sources of fruit fly introduction and unmanaged populations pose a high risk of dispersal to surrounding agricultural areas. Although management of urban fruit fly populations is recognised as being important for area-wide control programmes, its relative importance is rarely quantified. Identifying possible sources of fruit fly populations is important to the success of area-wide programs, as well as to on-farm management. We developed a modelling approach to analyse the spatio-temporal connectivity of fruit fly across urban-agriculture boundaries. For a case study, we examine Mediterranean fruit fly, Ceratitis capitata, outbreaks in two fruit growing regions in south-west Western Australia. Connectivity between population sources was defined using a dispersal kernel and routinely collected surveillance data from traps located across urban and agricultural areas. Spatio-temporal Bayesian models were then developed to quantify the extent to which unmanaged urban populations contribute to commercial orchards across each region. Our model results from two fruit growing regions indicate that population connectivity is a strong predictor of urban and commercial orchard Mediterranean fruit fly density. Models demonstrate that unmanaged urban outbreaks can contribute to increased pest pressure in surrounding orchards up to 2 km, but the urban contribution quickly declines over this distance. We also demonstrated that our models provide a means of predicting changes in Mediterranean fruit fly density across a region. Regional scale inference from our models may be particularly useful for sites where surveillance trapping data is unavailable. With an increasing risk of fruit fly incursions from expanding urban areas into agricultural regions, it is important to understand the processes driving population connectivity to target pest management strategies. By modelling surveillance trapping data and population connectivity, we can quantify how unmanaged urban pest infestations can contribute to pest pressure in nearby commercial orchards. Such information can help pest managers quantify the risk posed by unmanaged urban infestations when designing and implementing area-wide management.

Moscas frugívoras (Diptera: Tephritidae; Lonchaeidae) associadas a goiabeira: diversidade de espécies, parasitoides e flutuação populacional no Espírito Santo, Brasil

ABSTRACT The commercial cultivation of guava tree (Psidium guajava L.) occurs in all Brazilian regions, where fruit flies cause direct losses to production and affect fresh fruit exports due to quarantine restrictions. This study aimed to determine the incidence, diversity and population fluctuations of frugivorous fly species that infest guava trees, as well as to survey their associated parasitoids, in the Espírito santo state, Brazil. Fruits and flies captured in traps were sampled in three guava-producing regions. Anastrepha fraterculus (Wied.) was the main species associated with guava trees, particularly in the coastal region. Anastrepha chiclayae was recorded for the first time associated with guava trees in Brazil. Medfly was not considered an important species. Neosilba zadolicha was the most common Lonchaeidae species collected, but with low importance. Higher populations of frugivorous flies were found in hot and humid areas. Two population peaks of A. fraterculus were observed during October (spring) and from March to April (summer-autumn). Tephritid flies occurred in all surveyed regions, with higher infestations in the coastal area, followed by the northern and mountain regions, respectively. Doryctobracon areolatus and Aganaspis pelleranoi were the most common species of parasitoids; however, the natural biological control of frugivorous flies in guava trees was very low and had little impact on fruit fly populations.

Gendered barriers and opportunities for scaling integrated pest management practices along the mango value chain in Kenya

Abstract Mango (Mangifera indica L.) is an important source of food and income in Kenya, but production is hampered by the proliferation of invasive fruit flies (Bactrocera dorsalis). The International Centre of Insect Physiology and Ecology (icipe) and its partners have over the past 2 decades developed and disseminated an integrated pest management (IPM) package of interventions that effectively reduce fruit fly populations, but adoption is relatively low. In response to this low adoption, the authors conducted desk- and field-based qualitative and quantitative studies to better understand the gendered barriers and opportunities for scaling IPM practices along the mango value chain in Kenya. Twenty-four gender-disaggregated focus groups, 118 farmer surveys, and 63 key informant interviews with value chain actors were conducted. The results show that lack of access to IPM inputs, market constraints, and access to training are among the key barriers to and motivations for adopting IPM strategies in Embu County, Kenya.

Seasonal Abundance of Important Pests of Mango and their Correlation with Weather Parameters

The investigation was carried out at the Instructional Farm, ASPEE College of Horticulture and Forestry, Navsari Agricultural University (N.A.U.), Navsari, Gujarat, India during 2021-2022. The leaf webber, leafhopper, fruit fly, shoot borer, and thrips were found abundant, whereas the mealybug and stone weevils were very less. The leaf webber population exhibited a significant negative correlation with minimum temperature (r= -0.488*) and evaporation (r=-0.483*). The leafhopper population had a highly significant positive correlation with wind velocity (r= 0.577**) and rainfall (r= 0.823**) and a significant negative correlation with minimum temperature (r=-0.495*) and morning relative humidity (r= -0.414*). Fruit fly population exhibited a highly significant positive correlation with minimum temperature (r= 0.761**), wind velocity (r= 0.646**), and evaporation (r= 0.524**). There was a significant negative correlation of shoot borer population with minimum temperature (r= -0.804**), evening relative humidity (r= -0.467*), and wind velocity (r= -0.437*). Thrips population had a highly significant negative correlation with minimum temperature (r= -0.690**), evening relative humidity (r= -0.879**), wind velocity (r= -0.567**), and rainfall (r= - 0.541**) and a significant positive correlation with sunshine hours (r= 0.684**) and maximum temperature (r= 0.438*). Among natural enemies, ants, mantids, spiders, and chrysopa were found in the orchard and none of the parasitoids were reported.

The species composition, richness and diversity studies of fruit flies captured from the orchard of Nagpur mandarin

The present experiment was conducted to study the diversity of fruit flies in Nagpur mandarin orchard from different agro-ecological zones of Vidarbha region of Maharashtra, India. The fruit flies samples were collected from 18 places falling under 9 agro-ecological zone using methyl eugenol traps. Out of the total collected catches of fruit flies from each zones, Bactrocera dorsalis was found to be the most prominent species followed by Bactrocera zonata. The Z. cucurbitae and B. correcta which occupied third and fourth rank in species composition, respectively. The species viz., Zeugodacus duplicatus and Zeugodacus gavisus recorded very less abundance at all locations. Shannons index of diversity was maximum in Morshi followed by Katol. Simpson index was more at Tiwasa and Achalpur locations which indicated minimum diversity in the population of fruit flies. Higher diversity of fruit flies were recorded in Morshi and Katol followed by Amravati.

Methyl eugenol aromatherapy: a delivery system facilitating the simultaneous application of male annihilation and sterile insect technique against the peach fruit fly.

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

Differential Cold Tolerance on Immature Stages of Geographically Divergent Ceratitis capitata Populations.

Cold tolerance of adult medflies has been extensively studied but the effect of subfreezing temperatures on the immature stages remains poorly investigated, especially as far as different populations are regarded. In this study, we estimated the acute cold stress response of three geographically divergent Mediterranean fruit fly populations originating from Greece (Crete, Volos) and Croatia (Dubrovnik) by exposing immature stages (eggs, larvae, pupae) to subfreezing temperatures. We first determined the LT50 for each immature stage following one hour of exposure to different temperatures. Then eggs, larvae and pupae of the different populations were exposed to their respective LT50 for one hour (LT50 = -11 °C, LT50 = -4.4 °C, LT50 = -5 °C for eggs, larvae and pupae, respectively). Our results demonstrate that populations responded differently depending on their developmental stage. The population of Dubrovnik was the most cold-susceptible at the egg stage, whereas in that of Crete it was at the larval and pupal stage. The population of Volos was the most cold-tolerant at all developmental stages. The egg stage was the most cold-tolerant, followed by pupae and finally the 3rd instar wandering larvae. This study contributes towards understanding the cold stress response of this serious pest and provides data for important parameters that determine its successful establishment to unfavorable environments with an emphasis on range expansion to the northern, more temperate regions of Europe.