Fruit flies (Tephritidae) significantly threaten mango production and export in Uganda because of direct fruit damage and frequent export rejections, respectively. Accurate species identification is crucial for effective pest management. In Uganda, previous studies relied solely on morphological identification, making it difficult to identify cryptic species. Our study integrated morphological and molecular techniques to assess fruit fly diversity during the May-August 2023 mango season. Surveys were conducted across 20 mango farms in seven districts within Uganda’s two main mango-growing agroecological zones. A total of 256,107 fruit flies were trapped using food baits and para-pheromone lures targeting male Bactrocera, Ceratitis, Dacus , and Zeugodacus species. Morphological screening was performed at the Crop Science Laboratory of Makerere University Agricultural Research Institute, Kabanayolo, PCR confirmation at COVAB’s RTC lab, and Sanger sequencing at Inqaba Biotec. Twenty-one species were documented, ten of which were confirmed to species level: Bactrocera dorsalis, Ceratitis capitata, C. cosyra, C. anonae, Dacus punctatifrons, D. bivittatus, D. eclipsis, D. humeralis, D. armatus , and Zeugodacus cucurbitae . Three species, D. eclipsis, D. humeralis , and D. armatus were reported in Uganda for the first time. The remaining eleven species were identified to the genus level: Ceratitis, Carpomya, Rhagoletis, Dacus , and Zeugodacus. Bactrocera dorsalis was the most abundant (95.5%), dominant, and widely distributed species, followed by D. eclipsis and D. punctatifrons . These findings revealed a high diversity of fruit fly species in Ugandan mango orchards. Further studies and routine molecular surveillance are recommended for comprehensive species monitoring and improved pest management strategies.

MOF-enhanced colorimetric sensor array for early detection of citrus infestation by Bactrocera dorsalis

Simple, rapid and cost-effective DNA extraction techniques for detection of economically important fruit flies in India.

Reproduction is a fundamental process in the insect life cycle, with the ovary serving as the central organ governing oogenesis and fertility. Hormonal homeostasis, particularly juvenile hormone (JH) regulation, is critical for proper ovarian development. Bactrocera dorsalis (Hendel) is a globally invasive agricultural insect pest characterized by high reproductive capacity. MicroRNAs (miRNAs) are key post-transcriptional regulators of diverse biological processes, yet their roles in insect ovarian development remain incompletely understood. Here, we identify miR-318 as an ovary-enriched miRNA that regulates reproduction in B. dorsalis. Overexpression of miR-318 via mimic injection impairs ovarian development, reduces fecundity, and decreases egg hatchability, whereas CRISPR/Cas9-mediated knockout of miR-318 produces similar reproductive defects. Bioinformatic prediction and molecular assays reveal that miR-318 directly targets farnesol dehydrogenase (FolDH), an essential enzyme in the JH biosynthesis pathway, thereby modulating JH titers and female fertility. These findings establish a miR-318/FolDH regulatory axis upstream of JH that controls ovarian development and provide mechanistic insight into miRNA-mediated regulation of insect reproduction. Importantly, this work highlights the potential of miRNAs as upstream modulators of hormone biosynthesis and as targets for species-specific management of cyclorrhaphan dipteran pests.

Malay apple (Syzygium malaccense L.) is a tropical fruit species grown in the fruit garden section of Liwa Botanical Garden, West Lampung, Indonesia. Insect communities play an important role in agroecosystems because they consist of both pest species and beneficial organisms such as predators and parasitoids. This study aimed to determine insect diversity and dominance on Malay apple plantations in the Fruit Garden of the Regional Technical Implementation Unit (UPTD) of Liwa Botanical Garden. The observation was conducted from September to October 2021 using direct observation, pitfall traps, and yellow sticky traps across five sampling plots arranged diagonally. Insect identification was conducted based on morphological characteristics using relevant literature. Species diversity was evaluated using the Shannon–Wiener diversity index (H’), while dominance was measured using Simpson’s dominance index (C). A total of 1,594 insect individuals belonging to nine orders were recorded, including Diptera, Hymenoptera, Orthoptera, Hemiptera, Coleoptera, Lepidoptera, Dermaptera, Odonata, and Neuroptera. The diversity index (H’) was 1.44, indicating moderate diversity, while the dominance index (C) was 0.43, suggesting low dominance. Diptera was the most abundant order, dominated by fruit flies (Bactrocera dorsalis and Bactrocera cucurbitae). The results indicate that the insect community structure in the Malay apple plantation is relatively balanced, although fruit flies have the potential to become major pests. Increasing plant diversity through flowering plants (refugia) is recommended to support beneficial insect populations and maintain ecosystem stability.

Mirid bug feeding at the early fruit stage primes long-term systemic defenses in guava that suppress tephritid fruit fly colonization during ripening.

Bactrocera dorsalis (Hendel) is a highly destructive agricultural pest in tropical and subtropical regions. Infested areas are typically exposed to intense ultraviolet (UV) light, which can cause serious damage to insects. Extensive research has demonstrated that 6-4 photolyase (6-4phr) repairs UV-induced damage in various organisms. In this study, we found that UV-B stress significantly reduced the hatching, emergence, and adult survival rates of B. dorsalis. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) analysis showed that B. dorsalis 6-4 photolyase (Bd6-4phr) exhibited a distinct expression profile: it was most abundant in reproductive tissues, particularly the ovaries; it was notably up-regulated during key developmental stages; and it increased substantially after short-term UV-B stress. CRISPR/Cas9-generated Bd6-4phr-/- mutants showed markedly reduced hatching, emergence, and adult survival rates, which demonstrated significantly greater sensitivity to UV-B stress than wild-type (WT) individuals. After identical UV-B exposure, Bd6-4phr-/- mutants also exhibited higher whole-body accumulation of 6-4 pyrimidine-pyrimidone photoproducts (6-4PPs). Furthermore, recombinant Bd6-4phr protein reduced the concentration of 6-4PPs in vitro, indicating its role in 6-4PPs elimination in vivo. Lastly, expression of Bd6-4phr in Escherichia coli enhanced its UV tolerance and photoreactivation capacity, corroborating this enzyme's functional activity. In summary, Bd6-4phr enhances the environmental adaptability of B. dorsalis by mediating UV-induced DNA damage repair. Specifically, Bd6-4phr contributes significantly to B. dorsalis' adaptation to high-UV environments, which represents a molecular mechanism underlying this pest's exceptional environmental adaptability. Our work reveals new insights into explaining the powerful environmental adaptability of B. dorsalis. © 2026 Society of Chemical Industry.

Abstract Aims : Bactrocera dorsalis (Hendel) has been identified as a significant fruit pest in Asia, particularly Sri Lanka. Nonetheless, research on fruit fly population ecology and host phenology is scarce in Sri Lanka. Thus, the purpose of this study was to examine B. dorsalis fruit damage and population variation in relation to the fruiting phenology of selected commercial mango varieties in Sri Lanka. Methods : The study was carried out from January 2021 to January 2023 using eight main sampling sites (two sites per bioclimatic zone) and two commercial mango varieties [Karutha kolumban (Kc) and Willard (Wld)]. Once per month, flies were collected using standard methyl-eugenol field traps, and mature, ripe mangoes were also collected from study sites. Fruit damage levels and fruit fly emergence were studied in the laboratory. Main findings : The patterns of fruit damage and population dynamics variation of B. dorsalis are in accordance with the fruiting season of mangoes in each bioclimatic zone. Kc reported the highest field abundance, fruit infestation, pupae, and adult emergence compared to Wld. The intermediate zone recorded the highest increase in B. dorsalis ’s field abundance, fruit damage, and population dynamics for both Kc and Wld (in 2021 and 2022). Conclusions : The main mango harvesting seasons in every bioclimatic zone have a significant impact on variations in mango damage and the population dynamics of B. dorsalis . During the main mango harvesting season for both Kc and Wld, B. dorsalis shows the highest increase of their population and fruit damage in the intermediate zone, while the lowest values reported in the wet zone. Study findings are vital to implementing fruiting phonology-based management practices to control fruit fly damage and population.

The use of alternative hosts is a key strategy for enhancing the efficacy of parasitoid wasps in pest control. Pachycrepoideus vindemmiae is an important pupal ectoparasitoid of numerous agricultural and public-health pests, including Drosophila suzukii, Bactrocera dorsalis, and Megaselia scalaris. However, a suitable alternative host for the mass rearing of P. vindemmiae has yet to be established. In this study, we compared the biocontrol traits of P. vindemmiae reared on Drosophila melanogaster (PVm) with those reared on the larger alternative host Drosophila virilis (PVv). PVv exhibited a developmental duration similar to that of PVm but attained a significantly larger body size. PVv also showed higher survival under temperature stress (4 °C and 35 °C) and during starvation. Furthermore, PVv achieved significantly higher parasitism rates against Drosophila suzukii, B. dorsalis, and M. scalaris, likely attributable to its greater number of mature eggs and enhanced reproductive capacity. Transcriptomic analysis revealed up-regulation of genes associated with stress resistance, growth and development, and venom function, which may collectively contribute to the improved biocontrol performance of PVv. In summary, rearing P. vindemmiae on D. virilis enhances its biocontrol potential, offering a promising strategy to mitigate public-health risks and reduce agricultural economic losses. © 2026 Society of Chemical Industry.

Gut micriobiota are involved in adaptation of the invasive tephritid species Bactrocera dorsalis to temperature and diet stressors

Identifying pest infestations in fresh fruits is a crucial aspect of international trade. Currently, inspections rely on visual observations and destructive sampling, which are, in most cases, quite demanding. The detection of oviposition signs or early larval development is largely not feasible. Therefore, new methods that are sensitive and non-destructive are urgently needed to detect fruit fly infestation during inspections of fresh produce before their introduction and spread into pest-free areas. Portable electronic olfactory systems, or electronic noses (e-noses), are used in various scientific fields and industries. In this study, we evaluated the potential of a portable PEN3 electronic nose to discriminate between non-infested and infested fruits for three fruit fly species: Ceratitis capitata (Wiedemann), Bactrocera dorsalis (Hendel), and Bactrocera zonata (Saunders) (Diptera: Tephritidae). E-nose datasets were generated from samples of each combination of fruit, fruit fly species, infestation status, and storage condition. These datasets were used to develop classification models. The classification accuracy of the models ranged from 50 to 99% during calibration and cross-validation conditions. However, their performance decreased substantially when applied to independent datasets, highlighting limitations in robustness. These findings indicate that although the PEN3 system shows promise as a non-destructive detection tool, its performance is strongly influenced by seasonal and experimental variability. Further work is needed to incorporate multi-season and multi-variety datasets, improve calibration, and robust validation before practical implementation in field inspection systems.

Bactrocera dorsalis (Hendel) is a major fruit-feeding pest that poses a severe and persistent threat to the horticulture industry in tropical and subtropical regions. Methyl eugenol (ME) is a powerful male-specific attractant phytochemical and pheromone precursor that has been widely exploited in lure-and-kill pest management programs. Upon ingestion, ME is metabolized (E)-coniferyl alcohol (E-CF) and 2-allyl-4,5-dimethoxyphenol (DMP), which are stored in the male rectal glands and released during courtship to attract females. Despite its ecological significance, the fundamental molecular mechanism underlying ME perception remains poorly understood. Here, we performed a comparative transcriptomic analysis of ME-responsive and ME-non-responsive male B. dorsalis across four tissues (head, gut, midleg, and wing). A total of 15,727 genes were annotated, of which 970 were associated with odorant-binding proteins (OBPs), odorant receptors (ORs), gustatory receptors (GRs), ionotropic receptors (IRs), and chemosensory proteins (CSPs), as well as detoxification families comprising cytochrome P450s (CYPs), carboxylesterases (CaEs), glutathione S-transferases (GSTs), and uridine diphosphate (UDP)-glycosyltransferases (UGTs), and the stress-related heat shock proteins (HSPs) genes. Differential expression analysis identified 7222, 7763, and 6105 differentially expressed genes (DEGs) in the head, gut, and wings/midlegs, respectively, between ME-responsive and ME-non-responsive males. Notably, CYPs, UGTs, and HSPs involved in detoxification and stress response were significantly downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that CYPs were significantly enriched in metabolic detoxification pathways. These findings reveal a complex molecular interplay between olfaction and detoxification and suggest that ME induces coordinated genetic pathways supporting survival, reproduction, and environmental adaptability. This knowledge provides a foundation for the development of eco-friendly pest management strategies targeting these molecular mechanisms.

Comparative effectiveness of chemical and biopesticide-based control methods against Bactrocera dorsalis in mango orchards of Côte d'Ivoire

Understanding the mechanisms that enable invasive species to expand into novel thermal environments is key to predict their future distribution range under climate change. Plasticity is a key driver behind range expansion during invasion, yet the post-transcriptional regulatory mechanism underlying plasticity during range expansion remains less explored. Here, we performed an integr analysis of phenotypic, transcriptomic, and microRNA (miRNA) changes in a range-expanding invasive insect, Bactrocera dorsalis, under heat and cold acclimation. We found that populations at the invasive front exhibited reduced plasticity in fitness-related traits that were corroborated by genetic assimilation of frontloaded genes. Weighted Gene Co-expression Network Analysis uncovered important modules associated with acute cold tolerance of B. dorsalis and indicated thw gene as a critical network component. Furthermore, thw was found to be regulated by a key miRNA, miR-276b, with its function verified by our dual-luciferase reporter assay and RNAi-mediated knockdown experiment. Our findings suggested that miRNA-mediated regulation of plasticity might be key to allow invasive species to expand into novel thermal environments.

Bactrocera dorsalis (oriental fruit fly) is a destructive invasive pest threatening global agriculture. Although integrated pest management is applied, environmentally friendly genetic control methods are urgently needed. The development of such methods particularly relies on efficient genetic elements. In this study, we compared the transient expression of mScarlet-I driven by various Actin and PUb promoters in B. dorsalis embryos. The truncation of two strong promoters, BdActA3a and BdPUb, revealed that the 5.0-kb BdActA3a and 3.6-kb BdPUb promoters drove significantly higher expression than their truncated variants. Notably, the BdPUb promoter was highly effective in driving fluorescent protein expression in B. dorsalis. Using the 3.6-kb BdPUb promoter, we constructed a transposase plasmid BdPUb-3.6 kb>hyPBase. By co-injecting the BdPUb 3.6kb>mScarlet-I donor construct, we successfully generated a fluorescent transgenic strain with a transgenic efficiency of approximately 26%. The strain exhibited stage-specific fluorescence and maternal effect and the homozygotes showed fecundity comparable to wild-type controls. The high performance of the piggyBac transposase and the fluorescence screening system provides a substantial technical foundation for basic research and future development of genetically modified strains to control B. dorsalis.

Females of the oriental fruit fly (Bactrocera dorsalis) disproportionately oviposit in unripe fruits, despite their lower nutritional value compared to ripe fruits, but the sensory cues driving such counterintuitive site selection have not been determined. Here, using an oriental fruit fly-mango interaction system, we identified a specific flavonoid compound, hesperidin, as a major avoidance cue driving oviposition site selection in this species. Hesperidin accumulates as mango fruits ripen, and high concentrations suppress both larval growth and adult emergence. This indicates that higher levels of hesperidin exert a direct harmful effect on B. dorsalis larvae within ripe fruits. Interestingly, we found that B. dorsalis females perceive hesperidin via gustatory sensors on the ovipositor. The BdorGr28b gene is strongly expressed in the ovipositor, and we showed that the corresponding protein is the major hesperidin receptor. These results demonstrate that gustatory sensing via the ovipositor drives maternal avoidance of hesperidin to benefit the offspring in B. dorsalis. Our study provides insight into oviposition site selection in this species and the broader functional repertoire of insect gustation.

Feeding in animals is primarily regulated by the internal satiety state. Sulfakinin (Sk) is well known as a satiety signal that inhibits feeding. However, the underlying mechanism activating the Sk release is not yet fully understood, although the Sk for inhibitions of peripheral sensory systems, gustatory sweet and olfactory food smell sensors, were previously described. Here, in further investigations of Sk signaling pathways, we found the upstream and an additional downstream mechanism by using CRISPR/Cas9-mediated gene knockouts for the upstream gustatory receptor, Gr43a, and the downstream sulfakinin receptor 1, SkR1, in the oriental fruit fly. We demonstrated that the increased hemolymph fructose is sensed by GR43a, which activates the Sk signal in the intercerebralis insuline-like peptide (Sk-ILP) cells. The Sk-ILP acts as an autocrine signal activating the insulin-like peptide 5 (ILP5) as the ultimate satiety signal. This study demonstrated a fructose-Gr43a-Sk-SkR1-ILP5 pathway that regulates feeding behavior by sensing nutritional state.

This study aimed to contribute to the biological control of two economically significant fruit fly species, Bactrocera zonata and Bactrocera dorsalis. The research examined the effects of different host fruit species and artificial larval diets on their development. Experiments were conducted under controlled laboratory conditions (28 ± 2°C, 60-65% relative humidity). Specified five fruit varities were selected as a host including apple (Malus sylvestris), guava (Psidium guajava), mango (Mangifera indica), persimmon (Diospyros kaki), and pomegranate (Punica granatum). Key biological parameters taken into consideration were egg production, larval and pupal development time, survival rate, adult emergence percentages, and sex ratios. Comparisons were made between liquid and solid artificial diets under different host conditions. Results revealed that P. guajava was the most favorable host, yielding optimal egg production (297.3 ± 9.3), larval numbers (261 ± 3.2), pupal counts (237.6 ± 27.1), and adult emergence rates (86.9 ± 3.9%). Similarly, P. granatum exhibited the longest egg hatching duration (2.3 ± 0.3 days) and larval development time (7.6 ± 0.3 days). While M. sylvestris and D. kaki showed maximum pupal duration (4.3 ± 0.3 days). Solid artificial diets produced higher egg numbers (408 ± 108.3) and extended developmental periods compared to liquid diets, though liquid diets achieved superior adult emergence rates (80 ± 2.8%). It is concluded that P. guajava serves optimally for Bactrocera mass rearing. Moreover, solid diets enhance reproduction while liquid diets improve adult emergence. This can help and inform existing and future biological control programs.

Exokarst landscapes possess distinctive geomorphological and microclimatic characteristics that influence arthropod abundance and community structure in rice (Oryza sativa L.) ecosystems. Cooler and more humid microhabitats near karst formations can function as refuges that support resource stability, habitat connectivity, and trophic interactions. This study examined how distance from a karst cliff affects the abundance and composition of pest and natural enemy arthropods. Observations were conducted at three distances (0, 200, and 400 m), representing near-karst, transitional, and outer-karst microclimate zones in Kalabbirang, Bantimurung District, Maros Regency, South Sulawesi, Indonesia. A total of 1,483 individuals from 21 species were recorded. Arthropod abundance was highest at 400 m (549 individuals), followed by 0 m (477 individuals) and 200 m (457 individuals). Although total abundance was lower at 200 m, this site showed the highest species richness (S = 2.78), Shannon diversity (H′ = 2.15), and evenness (E = 0.76), indicating a more balanced community structure. Dominance was greatest at 400 m (D = 0.20), largely due to the high abundance of Coccinella sp. (205 individuals). Bactrocera dorsalis was most abundant at 0 m (125 individuals), Nephotettix virescens peaked at 200 m (106 individuals) but declined at 400 m (10 individuals), while Leptocorisa oratorius increased toward 400 m (70 individuals). Predator communities were dominated by Lycosa pseudoannulata (317 individuals). Correlation and PCA results indicate that karst-related microclimatic gradients structure arthropod communities and contribute to stronger natural pest suppression in outer-karst zones.

Cuticular microbial communities influence insect-pathogen interactions, yet their protective roles remain incompletely understood. These microbial defenses are critical in pest species like Bactrocera dorsalis, where microbial symbionts may shape resistance to biological control agents. We show that the cuticular microbiota of Bactrocera dorsalis enhances resistance to the entomopathogenic fungi (EPF) Beauveria bassiana and Isaria fumosorosea through dual immune and chemical mechanisms. Gnotobiotic assays demonstrate that specific bacterial isolates (Microbacterium, Psychrobacter, and Staphylococcus) promote host survival and defense by stimulating Toll/IMD signaling pathway and up-regulating antimicrobial peptides (AMPs) such as defensin, attacin, and cecropin. In contrast, non-cuticle-associated bacteria (Escherichia coli and Staphylococcus aureus) failed to enhance survival and immune responses, indicating that protection is microbiota-specific rather than a result of general bacterial exposure. In parallel, bacterial volatiles, such as phenol, indole, and eicosane, along with extracellular enzymes including chitinase, cellulase, protease, and lipase, suppressed fungal germination and hyphal growth. Importantly, these protective effects were found to vary with host age, indicating age-dependent modulation of microbiota-mediated defense. Our findings revealed that cuticle-associated bacteria protect their host through complementary immune and chemical pathways. These microbiota act as an active barrier, and microbial metabolism interacts with host immune signaling. By distinguishing specific cuticle-derived effects from non-specific bacterial stimulation, this study highlighted the role of microbiota in modulating fungal susceptibility and supports their application in developing next-generation biocontrol strategies in pest management. © 2026 Society of Chemical Industry.