This study investigated the effect of nutrition on development of wings and adult body condition of Bactrocera dorsalis (Hendel), an exotic pest of Asian origin and a species of economic importance in South Africa. Six host fruit types were used to rear B. dorsalis: mango, guava, orange, grapefruit, papaya and apple. One day after emergence, adults were used for tethered flight assessments using computerised flight mills. Additional flies were assessed in terms of wing morphology using geometric morphometrics, flight muscle mass, and lipid content. There were significant differences in the larval and pupal developmental time as well as larval and pupal survival amongst the tested host fruit, with orange tending to lead to poor performance in development and survival. Host fruit type and sex had a significant effect on the flight performance and wing morphology of B. dorsalis. There was a significant difference between female and male wing shapes, indicating the presence of sexual dimorphism. Females were more likely to fly than the males, and flies that developed on grapefruit covered the shortest distance. Host fruit type influenced both the lipid content and the flight muscle mass, with development in grapefruit leading to the lowest values. Our results show that variation in flight performance of B. dorsalis individuals can be associated with differences in resource quality during their development, and may lead to regional and temporal differences in the ability of the pest to disperse.

The success of trypanosomes in transitioning between hosts and life stages depends on their ability to manipulate host metabolism, immunity, and behavior. Pathogen-favoring behaviors often link tsetse flies’ host behavioral plasticity and sensory adaptations, but the underlying mechanisms remain unclear. To uncover the molecular basis regulating neuronal sensitivity and transmission behavior in tsetse flies, we applied transcriptomics, metabolomics and validated by RT-qPCR and behavioral assays. Uninfected Glossina pallidipes were more attracted to Trypanosoma congolense-infected mice and metabolites from infected cow urine than to healthy ones. T. congolense infection alters host metabolic pathways, modifying the composition of volatile organic compounds in mice and cattle, which enhanced fly attraction. Infection modulated cellular signaling across multiple sensory modalities, including olfaction, vision, taste, thermosensation, and immunity in G. pallidipes. Trypanosome associated odors doubled the catch of infected G. pallidipes in the field, reducing infected flies by 75% and diseases prevalence in cattle by 40% based on agent-based model. These findings reveal the molecular interaction between T. congolense, G. pallidipes, and cattle, highlighting how the parasite manipulates multiple pathways to enhance adaptation, multiplication, and transmission. Muti-omics investigation reveals how trypanosomes manipulate their vertebrate host metabolites and tsetse flies’ multiple sensory modalities and immunity to enhance its survival and transmission.

BACKGROUND:Drosophila suzukii, commonly known as spotted wing drosophila (SWD), is a highly invasive and economically major pest that inflicts significant damage on soft-skinned fruit crops, including raspberries, blueberries, strawberries, blackberries, cherries and grapes. The recent invasion of D. suzukii in Africa represents a key impediment to the berry industry on the continent. Conventional control strategies for this pest rely heavily on chemical insecticides, which pose several adverse side effects on biodiversity and environmental health. In this study, we evaluated five Metarhizium anisopliae isolates (ICIPE 7, ICIPE 18, ICIPE 20, ICIPE 30, ICIPE 78) for development as a biopesticide for D. suzukii management, by assessing both their direct pathogenicity and indirect effects via fungal volatile-mediated behavioral responses. RESULT:All five M. anisopliae isolates led to high mortality in D. suzukii. The median lethal time (MLT50) showed that the ICIPE 78 isolate had the fastest action (4.75 ± 1.03 days) followed by ICIPE 7, ICIPE 18, ICIPE 30, and ICIPE 20, with MLT50 of 5 to 8 days. ICIPE 78 was horizontally transmitted by donor flies, and the fertility of recipient females was negatively impacted. We further documented that ICIPE 78 induced significant attraction to D. suzukii. Moreover, sporulated cadavers hosting ICIPE 78 attracted and infected healthy flies. CONCLUSION:The high pathogenicity of ICIPE 78 and its attraction to D. suzukii could be explored for pest suppression, especially as this isolate is already commercialized against other pests, which could facilitate its registration for use against D. suzukii through label extension. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is a major pest of fruit production in many countries around the world. Control strategies include the male annihilation technique (MAT), which uses the strong male attractant methyl eugenol (ME), or the sterile insect technique (SIT). Although the simultaneous application of MAT and SIT could enhance suppression, this is currently precluded because released sterile males are attracted to and killed by ME-baited devices deployed for MAT. A potential solution is to reduce B. dorsalis male response to ME through dietary supplementation prior to release. However, long-term exposure to ME in mass-rearing facilities poses a risk to human health, and alternatives are needed. In this study, we determined (1) the effects of four semiochemicals (ME, eugenol, trans-cinnamic acid, and zingerone) mixed into the adult diet at different concentrations on B. dorsalis mortality in the laboratory, and (2) their effects on response by males to ME baited traps in semi-field conditions. Each semiochemical was incorporated at different concentrations into a 3:1 sugar-hydrolysed yeast mixture, which were then provided for 48 h to males of different ages. Males supplemented at age 0 exhibited high mortality, especially with ME and eugenol. Males fed ME and eugenol at the lowest concentration of 1.25% before release into field cages were rarely caught in ME baited traps. Our findings suggest that feeding sterile males low concentrations of ME or eugenol before release allows simultaneous application of MAT and SIT, and that eugenol is a viable alternative to ME.

The capacity of living organisms to withstand stress may be energetically expensive, thereby placing a demand on body nutrient stores and any nutrients that might be linked to coping with that stress. Here, we tested the hypothesis that desiccation-resistant Ceratitis capitata (Diptera: Tephritidae) and desiccation-sensitive Ceratitis rosa differentially oxidise nutrients to counter desiccation stress and facilitate recovery. Lines of flies from both species had their body macronutrient stores experimentally enriched with one of three 13C tracers: leucine (enriches proteins), palmitic acid (enriches lipids) and glucose (enriches primarily carbohydrates), and were then subjected to a regimen of desiccation stress followed by recovery. We used flow-through respirometry and 13C-breath testing to detect changes in metabolic rates and macronutrient oxidation. Ceratitis capitata, unlike C. rosa, showed highly flexible metabolic rates and nutrient oxidation. The former upregulated oxidation of both carbohydrates and lipids whereas protein oxidation was only upregulated during recovery from desiccation. This provides novel support for biochemical pathway (macronutrient) flexibility enhancing the survival of a desiccation-resistant invasive species over a desiccation-sensitive species.

The effectiveness of odour-based lures for insects is related to their active space, the air volume around an odour source in which an insect will detect and move towards it. This principle applies to protein baits laced with toxicants that are used as either sprays or stations to suppress pest fruit fly populations. Whilst protein bait spray droplets represent multiple odour sources distributed across a tree, a protein bait station being a device containing the bait and hung on a tree acts as a single odour source within the same arena. This study investigated responses by the females of three fruit fly pests [Bactrocera dorsalis (Hendel), Ceratitis capitata (Wiedemann) and Ceratitis cosyra (Walker) (Diptera: Tephritidae)] to protein bait applied at two densities. Unmated female flies were fed on a diet that was either protein-deficient (sugar only) or protein-rich (sugar and hydrolysed yeast) in the laboratory for 10 days. Fly responses to either 10 droplets of 200 mu L each or a single droplet of 2000 mu L of a protein hydrolysate solution were quantified in field cages placed in a lemon orchard. Bait density significantly affected protein response by B. dorsalis, C. capitata and C. cosyra, with the majority responding more to higher protein bait density. Additionally, dietary history significantly influenced responses across all species, with flies fed a protein-deficient diet responding more than those fed protein. These results demonstrate that protein bait may be more effective for fruit fly control when distributed as multiple points on a tree compared to a single point, and that protein food sources in an environment would reduce the efficacy of control using protein bait.

ABSTRACT Globally, citrus production areas are threatened by greening diseases, also known as Huánglóngbíng (HLB), associated with phloem‐limited gram‐negative species of the genus Candidatus Liberibacter. Those pathogens are transmitted by either the Asian citrus psyllid, Diaphorina citri Kuwayama 1908 (Hemiptera: Psyllidae), or the African citrus triozid, Trioza erytreae (Del Guercio, 1918) (Hemiptera: Triozidae). Asian citrus greening associated with ‘ Candidatus Liberibacter asiaticus’ (HLB‐CLas) is the most severe form of the disease and is primarily transmitted by D. citri , although T. erytreae can also acquire and transmit the pathogen. African citrus greening associated with ‘ Candidatus Liberibacter africanus’ (HLB‐CLaf), vectored by T. erytreae , caused major yield losses in South Africa during the 1970s. Diaphorina citri was detected in East Africa in 2015, while T. erytreae was reported in Southern Europe around the same time. Currently, the most effective way to limit citrus tree infection by HLB is to manage its vectors, which requires that their biology be understood. While there is extensive literature on D. citri , we show that T. erytreae is currently understudied. Using a systematic map approach, we reviewed the literature for T. erytreae and identified knowledge gaps for this species. Among the 86 articles identified, most were on distribution and monitoring (31.03%) and control methods (17.24%). Topics such as thermal biology, chemical ecology or host plants represent the largest knowledge gap, with each category representing < 7% of the research literature.

Semiochemicals are produced by diverse taxa to mediate intra- and interspecific communication. These chemical cues are becoming increasingly important in integrated pest management (IPM) for manipulating key behaviors such as mating, foraging, and host selection in both plant–insect and insect-insect interactions. Semiochemical-based approaches regulate pest populations through techniques such as monitoring, mass trapping, and mating disruption. Understanding the chemical cues that mediate these interactions is crucial for developing sustainable and targeted pest management options. This review explores the role of semiochemicals in managing insect pests, with a focus on the fall armyworm (Spodoptera frugiperda), a globally significant pest native to the Americas. We discuss composition, variability, efficacy, specificity, and applications of plant volatiles and sex pheromones in pest management. Additionally, we address challenges associated with the adoption of semiochemical-based approaches and highlight emerging research directions to enhance their integration into IPM programs. By synthesizing current knowledge, this review underscores the potential of semiochemical-based strategies to reduce reliance on conventional insecticides while improving pest control efficiency. The strategic application of plant volatiles and sex pheromones in agricultural systems offers an opportunity to develop more ecologically sound and sustainable pest management practices, thereby fostering resilient cropping systems with minimal environmental impact.

Some thrips (Thysanoptera) species are presumed to injure avocado and macadamia trees and fruit when feeding as nymphs and adults. We investigated the abundance and species richness of thrips and monitored fruit and nut set and damage on four avocado (Fuerte, Hass, Maluma and Pinkerton) and macadamia (695, 814, 816 and A4) cultivars. Different stages of avocado fruit (1–3, 4–6 and 7–9 cm) or macadamia nut development (closed racemes, nut set, nut size 1–1.5 cm and nut size 3–4 cm) were sampled over two seasons in the Levubu region of Limpopo Province, South Africa. Thrips development on fruit, nuts and leaf flush was recorded to verify the thrips species causing damage. A total of 15 535 thrips were collected during August–January 2020–2021 and 2021–2022. Six thrips morphotypes were identified across macadamia and avocado orchards: Scirtothrips aurantii Faure (Thripidae), Thrips tenellus Trybom (Thripidae), Haplothrips gowdeyi Franklin (Phlaeothripidae), Frankliniella occidentalis Pergande (Thripidae), Megalurothrips sp. (Thripidae) and Caliothrips sp. (Thripidae). Thrips were less abundant in the 2020/2021 season compared to the 2021/2022 season and in avocados than in macadamias. Pinkerton (2020/2021: 4.9 ± 0.8 and 2021/2022: 13.1 ± 0.2) and Fuerte (2020/2021: 6.9 ± 1.3 and 2021/2022: 7.5 ± 0.1) had the highest damage and fruit set per inflorescence in both seasons. Fruit size 1–3 cm had a mean damage of 3.4 ± 0.8 in 2020/2021 and 4.0 ± 0.7 in 2021/2022, 4–6 cm had 5.3 ± 0.9 and 4.7 ± 0.7 in 2021/2022, and 7–9 cm had 5.2 ± 0.9 in 2020/2021 and 5.0 ± 0.8 in 2021/2022. Macadamia cultivars and developmental stages most affected by thrips were dependent on the season. Our results suggest that damage occurs earlier in fruit or nut development, and Fuerte avocados and Macadamia 695 were the least susceptible to thrips damage. S. aurantii larvae developed from all sampled avocado and macadamia tissues and were able to persist until the adult stage, confirming it as the main damaging thrips species of avocado and macadamia in the Levubu region.

Plant-derived phenylpropanoids are semiochemicals that are often highly attractive to Bactrocera (Diptera: Tephritidae) males. One of these semiochemicals, methyl eugenol (ME), is used in the male annihilation technique (MAT) for the management of B. dorsalis (Hendel), a destructive horticultural pest. It is not normally viable to simultaneously implement MAT with the sterile insect technique (SIT), as released sterile males are attracted to MAT devices. However, prior semiochemical exposure can reduce the later response of Bactrocera males to the same or another semiochemical, which may allow the synchronous application of MAT and SIT. We determined how the interaction between semiochemical pre-feeding, weather, and fly physiology impacted the response of male B. dorsalis to ME baited traps. Response by a known number of males in field cages was determined in relation to temperature, relative humidity, semiochemical pre-feeding (ME, eugenol, or none), diet (protein supplemented and protein deprived) and age (4, 10 and 20 days old). Semiochemical pre-feeding of both ME and eugenol equally decreased the response of males that were 10 days old, or older, to ME baited traps. Adult diet had no effect on the response of males to ME baited traps. Response improved as temperature and relative humidity increased. These results highlight the feasibility of synchronous MAT-SIT programmes targeting B. dorsalis and the viability of continued protein supplementation of sterile males. We show that eugenol is an alternative to ME for suppression of male B. dorsalis response to MAT devices and that weather conditions significantly affect the variability and reliability of abundance estimates from trap captures.

The application of protein baits forms the core of fruit fly (Diptera: Tephritidae) control measures in many orchard environments. Protein baits target adult fruit flies, which need protein for reproductive maturation. A proper understanding of the factors influencing fruit fly responses to protein is required to optimise control outcomes. In this study, responses to protein bait by three fruit fly species, Ceratitis capitata (Wiedemann), C cosyra (Walker), and Bactrocera dorsalis (Hendel), were investigated. This was done in two field cages erected over lemon trees within an orchard. The response of each species to protein bait presented as a station and positioned at different heights within the tree canopy was evaluated. For each species, effects of fly age, sex, and nutritional status were evaluated under conditions of varying temperature and relative humidity. The highest response occurred when protein baits were placed in the middle to upper tree canopy. Species, nutritional status, sex and age also affected protein foraging. Ceratitis capitata responded more to bait compared to B. dorsalis and C. cosyra. The lowest response to protein bait was by one-day-old protein fed flies, while 10-day-old protein deprived flies were most responsive. Protein deprived females were more attracted to protein than males fed the same diet. Flies responded to bait when temperatures were between 20 and 30 degrees C. Based on the results, the success of protein baits in controlling fruit flies in a tree canopy is height dependent and can be lower in areas with alternative protein sources.

Little is known about how past and current thermal environment interact to determine dispersal in novel environments, and thus invasion potential of major agricultural pests. In this study, we tested experimentally how adult thermal history affects flight-related traits under diverse thermal conditions in three major agricultural pests of invasion concern: Bactrocera dorsalis, Bactrocera zonata and Ceratitis capitata. Across all species, the main factor affecting flight performance was body mass, with heavier individuals performing best. Both current and, to a lesser extent, past thermal environments affected flight performance and periodicity (flight interruptions), although their interaction was rarely significant. Furthermore, we show that 20 degrees C acclimation can have deleterious effects regardless of thermal conditions during flight, particularly in Bactrocera females, which had decreased flight performance and increased flight periodicity when acclimated at this temperature. The thermal environment during flight affected both flight periodicity and performance mainly in females of C. capitata and B. dorsalis, while only flight performance was affected in B. zonata males. When compared to warmer temperatures, flight at 20 degrees C tended to reduce flight performance, but flight periodicity increased at 30 degrees C compared to 20 degrees C. Overall, the flight performance of B. dorsalis was greater than that of C. capitata or B. zonata, regardless of the past and present thermal environment, but flight periodicity was lower in C. capitata. In all three species investigated, optimal flight performance occurs around 25 degrees C, and flies will therefore cover more distance around this temperature. The lack of interaction between past and current thermal environments in these three species indicates that flight-related traits may have low thermal plasticity. Finally, our results suggest that a reduction in thermal variability and average temperatures increasing temperate areas by a few degrees with climate change may facilitate movements of tropical tephritid pests in new areas at higher latitudes.Read the free for this article on the Journal blog.

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is a damaging crop pest that has recently invaded and established across Africa from its native tropical and subtropical regions of the Americas. To develop an improved monitoring system for the FAW, we evaluated five commercial sex pheromone lures (Shenzhen Bio-global, FALLTRACK, Enlure, P061-Lure and PH-869-1PR), three trap types (delta, bucket, and water-pan) and six placement heights (ground level, 0.5, 1, 1.5, 2 m above the ground and 0.2 m above the crop canopy) in replicated field trials at representative maize growing agroecologies of Kenya. Water-pan traps baited with the lures PH-869-1PR and P061-Lure captured the highest number of moths, whereas delta traps captured the least number of moths regardless of the pheromone lure used. Water-pan traps baited with Enlure and FALLTRACK lures captured more non-target insects than traps baited with the other lures. Traps placed at 1.5 m and 2 m above the ground captured more FAW moths than traps at the other placement heights. Genetic studies revealed no discernible differences between lures in the proportions of FAW strains captured. We recommend PH-869-1PR baited water-pan and bucket traps at a placement height of 1.5 m above ground for monitoring the FAW in Kenya. Moreover, we discussed the merits and drawbacks of different pheromone lure and trap combinations, and placement heights.

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.

The oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is an invasive species that has rapidly spread across the African continent, endangering the security of agricultural industries. The sterile insect technique (SIT) is being investigated as a viable additional pest management tool to suppress B. dorsalis populations after its successful implementation in other parts of the world. There is evidence to suggest that pre-release nutritional and semiochemical treatments for sterilised males can enhance their competitive performance against wild type males in SIT programs. This study examined how sterilisation, a diet rich in protein (addition of yeast hydrolysate) or containing semiochemicals (methyl eugenol or eugenol) affected the resting metabolic (RMR) of male B. dorsalis at different temperatures (15 - 30 degrees C), measured using flow-through respirometry. Our results indicated that the negative effect of sterilisation on RMR decreased as temperature increased and that duration of exposure to semiochemicals for 1 to 4 days was not a significant influencing factor on male B. dorsalis RMR. Protein-rich diet increased average RMR, but the difference in RMR between dietary groups decreased as temperature increased. Semiochemical feeding reduced the average RMR in male B. dorsalis. The difference in RMR between males that consumed semiochemical and those that did not increased with as temperature increased.

Honey bee (Apis mellifera) thermoregulation plays an integral part in their behaviour and physiology and has been shown to be vulnerable to the effects of neonicotinoid insecticides. Flight muscles are a crucial source of physiological heat as well as being vital for behavioural heat regulation, and are negatively affected by neonicotinoid insecticides. In this study, we evaluated the flight efficiency and capacity of Apis mellifera scutellata under the influence of both elevated ambient temperatures and sublethal neonicotinoid exposure. The various aspects of flight; success, distance, speed, and duration, were not notably affected by these factors. However, the honey bees' ability to initiate a successful flight was significantly affected by neonicotinoid exposure. Such a reduction in honey bee flight capacity, and flight muscle function in general, especially under the increasing frequency and intensity of hot weather events, is cause for concern when considering legislation and use of these neonicotinoids in the agricultural and suburban setting.

A BSTRACT . The Huanglongbing (HLB) disease has had a devastating impact on several citrus production areas across the world. The disease is associated with three phloem-limited bacteria of the Candidatus Liberibacter group, which can be vectored by citrus-infesting psyllids. In Florida, it is vectored by Diaphorina citri, , also known as Asian citrus psyllid (ACP), and in South Africa, by a native species, Trioza erytreae, , or African citrus triozid (ACT). For better disease management, continued monitoring of these vectors is highly recommended. Furthermore, it is important to keep track of other related psyllids that reside in citrus environments (e.g., the South African native Diaphorina specimens DN, such as D. virgata, D. punctulata, and D. zebrana), ), as well as natural predators of psyllids (e.g., lady beetles, LB). Among the tools used to monitor pests in the field, sticky traps are one of the most common and widely used. Analyzing the traps and identifying the specimens of interest usually require specialized personnel, which can be costly and time-consuming. In an effort to automate this process, a web application called "Psyllid Detector" was developed. Three YOLOv7-based object detection algorithms (YOLOv7, YOLOv7-ResNet50, and YOLOv7-ResNeXt50) were selected to train six models using two datasets (South Africa and Florida datasets) composed of yellow sticky trap pictures taken from several citrus orchards. Three models were trained to detect ACP and LB using the Florida dataset, and three were trained to detect DN and ACT in the South Africa dataset. The models trained with the original YOLOv7 for both datasets showed the best overall results. For example, for the ACT detection in the South Africa dataset, precision, recall, and F1 scores of 90%, 70%, and 79% were achieved, respectively. By automating the process of insect detection, farmers can save time and resources and make informed decisions about pest control measures.

Knowing how environmental conditions affect performance traits in pest insects is important to improve pest management strategies. It can be informative for monitoring, but also for control programs where insects are mass-reared, and field-released. Here, we investigated how adult thermal acclimation in sterile Bactrocera dorsalis affects dispersal and recapture rates in the field using a mark-release-recapture method. We also considered how current abiotic factors may affect recapture rates and interact with thermal history. We found that acclimation at 20 or 30 °C for 4 d prior to release reduced the number of recaptures in comparison with the 25 °C control group, but with no differences between groups in the willingness to disperse upon release. However, the deleterious effects of acclimation were only detectable in the first week following release, whereafter only the recent abiotic conditions explained recapture rates. In addition, we found that recent field conditions contributed more than thermal history to explain patterns of recaptures. The two most important variables affecting the number of recaptures were the maximum temperature and the average relative humidity experienced in the 24 h preceding trapping. Our results add to the handful of studies that have considered the effect of thermal acclimation on insect field performance, but notably lend support to the deleterious acclimation hypothesis among the various hypotheses that have been proposed. Finally, this study shows that there are specific abiotic conditions (cold/hot and dry) in which recaptures will be reduced, which may therefore bias estimates of wild population size.

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