Huanglongbing (HLB) is considered the most serious Citrus disease for which there are currently no effective control methods. The putative agents of HLB, Candidatus Liberibacter asiaticus (CLas), and the vector Diaphorina citri, are widespread in citrus regions, causing losses in citrus cultivation worldwide. Studying the interactions between D. citri and CLas can elucidate disease epidemiology and determine specific targets for HLB control. This work aimed to improve our understanding of the host-bacteria (D. citri-CLas) relationship, focusing on cysteine peptidase (DcCathL) and its inhibition by citrus cystatin (CsinCPI-2). In this study, a combination of qPCR, FISH, and immunolocalization techniques was employed to detect DcCathL genes or proteins in CLas-free or -infected D. citri samples. To verify the effect of DcCathL inhibition on insect survival, an artificial diet assay containing recombinant CsinCPI-2 was performed with infected and healthy D. citri nymphs and adults. Accordingly, a relative expression of DcCathL 1.23 times higher and an approximately 3.3 times greater DcCathL transcripts in gut tissue were demonstrated in CLas-infected compared to CLas-free insects. Furthermore, the presence of DcCathL protein was detected in the gut, ovary, and salivary glands of D. citri, concentrated at the peripheral regions of the cells. The fluorescence signal associated with DcCathL indicates that the gut of infected D. citri contains 4.81 times more protein than the gut of a healthy insect. Similarly, the protein levels in the salivary glands and ovaries of infected insects were 1.38 and 1.1 times higher, respectively, compared to those of CLas-free insects. The efficacy of the artificial diet in delivering the recombinant protein to the insect was demonstrated by the detection of green fluorescent protein (GFP) in the intestinal tract of nymphs and adults. Finally, the CsinCPI-2 demonstrated a substantial increase in mortality among CLas-free nymphs (df = 1, p < 0.0001) and CLas-free or CLas-infected adults (df = 1, p = 0.0001). Thus, the development of inhibitors that can disrupt the interactions between bacteria and vectors by blocking DcCathL activity may represent a promising strategy to prevent the spread of HLB disease.
Leaf-cutting ants are dominant herbivores in Neotropical ecosystems, yet the evolutionary origins of their cutting preferences remains unresolved. We investigated whether grass-cutting specialization emerged from a single evolutionary innovation or multiple independent origins. We compiled the predominant cutting behavior of each leaf-cutting ant species and classified them as dicot, grass, or grass-dicot cutters. Integrating these data into a time-calibrated phylogenetic framework allowed us to reconstruct the evolutionary history and diversification of leaf-cutting behavior in these ants. Divergence-time analyses date the origin of leaf-cutting ants to the early Miocene, major crown clades diversified during the late Miocene to early Pliocene, a period of increasing climatic seasonality and landscape openness in South America. The evolutionary history of these ants is strongly influenced by large-scale climatic and geological processes, as evidenced by their origin and major diversification events in close association with Miocene-Pliocene environmental changes. Phylogenetic analyses clarify the contrasting diversification dynamics of Acromyrmex, Amoimyrmex and Atta. Acromyrmex traces back to ~15 Ma and is structured into at least four major clades, with a distinct grass cutting clade. In contrast, Atta is a younger lineage characterized by rapid diversification during the Pliocene. Amoimyrmex occupies an early diverging position, indicating an independent origin of grass cutting within the group. Ancestral state reconstructions consistently indicate that dicot cutting is the ancestral condition, with grass and mixed dicot-grass cutting evolving independently multiple times. These repeated transitions coincide with the temporal expansion of open, grass-dominated habitats and likely reflect adaptive responses to new ecological opportunities. The convergent evolution of grass-cutting strategies, despite the mechanical and ecological challenges posed by silica-rich grasses, suggests that cutting preferences are evolutionarily flexible yet functionally constrained traits. Together, our results suggest that grass-cutting is not phylogenetically conserved, but rather represents a recurring adaptive response to environmental change. This highlights how major landscape transformations during the Miocene-Pliocene period promoted repeated ecological innovation in socially complex herbivores.
Faba bean (Vicia faba L.) is one of the most important cool-season legume crops worldwide, particularly in the Mediterranean regions. It plays a crucial role in cereal-based crop rotations and serves as an accessible and cost-effective protein source for both human diets and livestock feed. Despite its significance, faba bean production is heavily impacted by the stem borer Lixus algirus L. (Coleoptera: Curculionoidea), a prominent insect pest in the Mediterranean region. This research aimed to assess the impact of L. algirus on grain yield and seed nutritional profile of a local variety 'Defes'. The experiment was conducted using insect-proof cages at ICARDA - Marchouch research station during the 2018-2019 and 2019-2020 seasons. The findings revealed that L. algirus infestation caused grain yield losses ranging from 14% to 20%. Larval feeding within plant stems significantly altered seed nutritional composition compared to seeds from non-infested plant, ICP-OES analysis revealed significant declines were observed in magnesium (44%), manganese (38%), calcium (37%), zinc (30%), and iron (27%) concentrations in seeds collected from infested plants. In contrast, an increase in seed protein content and total sugar levels was recorded in infested plant seeds compared to non-infested plants. Similar results were observed for both essential amino acids (such as threonine, isoleucine, leucine, phenylalanine, histidine, lysine, and arginine) and non-essential amino acids (including glutamic acid, tyrosine, and alanine). Multivariate analyses, including PCA and correlation, revealed distinct nutrient and morphological trait patterns between infested and non-infested faba bean samples across both seasons. Collectively, these results show that L. algirus not only reduces grain yield but also reconfigures seed nutritional quality, lowering mineral density despite higher protein and sugars, highlighting the need for integrating host plant resistance for stem borer management and timely IPM to preserve both productivity and food/feed quality.
Honey bee health is adversely affected by numerous biotic and abiotic stressors, such as the extensive use of pesticides, which reduce survival and, even at sublethal doses, impair fitness and behaviour, including learning ability. The proboscis extension reflex (PER) is a widely used method to investigate associative learning in different insect species, such as Apis mellifera ligustica, when exposed to biotic and abiotic stresses. PER protocols require careful insect handling and accurate timing of stimulus application for effective conditioning and precise learning behaviour assessment. Despite the considerable amount of literature on this topic, information on automatising PER protocols for evaluating a large number of insects is limited. In this study, under laboratory conditions we evaluated whether exposure to different lethal concentrations (LC0.2 and LC20) of the natural bioinsecticide spinosad affects olfactory learning in groups of twenty worker bees within the same experimental cycle. For this purpose, we developed and validated an automated, microcontroller-based open-source device designed to standardise key steps of the PER conditioning protocol. Spinosad is a neurotoxic molecule that is known to induce mortality in honey bees, as well as behavioural impairment on locomotion and orientation at low doses. Surprisingly, possible effects on associative learning evaluated through PER are unknown. The sequential steps of the PER protocol were mechanised using a rotating carousel, where the conditioned stimulus was automatically released. The operator manually applied the unconditioned stimulus to the antennae, provided the rewarding solution, and recorded whether each insect exhibited PER behaviour. Bee responses were instantly transmitted to a laptop using a basic serial data transfer protocol and revealed decreased PER response (about 25%) for both spinosad concentrations at 20 min after the last conditioning trial. After small adaptations and validation, we expect that the device can be adopted both in laboratory and field conditions to investigate PER response in other bees, e.g., wild pollinators and bumblebees. This work aligns with current attempts to develop novel tools for monitoring biopesticide effects on pollinator health in changing environments.
Spatial repellents (also called spatial emanators) are widely marketed for personal protection against mosquito bites, yet their real‑world performance varies substantially and is rarely evaluated under standardized field conditions. This study quantified the protective efficacy of six consumer‑available repellent devices at paired urban (Aedes-dominated) and rural (Anopheles-dominated) field sites in Mali, West Africa. Products included a Dynatrap® Mosquito Repellent electronic device with an 8.83% transfluthrin-containing replaceable heat-activated cartridge, a Thermacell® E90 Rechargeable Mosquito Repeller electronic device with a 5.5% transfluthrin-containing replaceable heat-activated cartridge, two mosquito coils (Hassana containing 0.08% meperfluthrin and PIC® containing 0.6% pyrethrins), a Cutter® CitroGuard® Candle containing 3% citronella oil, and an Isotronic mosquito repellent device with an oscillating frequency technology. Each product was tested in wind‑controlled V‑shaped field plots using three CO2‑baited CDC‑UV traps, positioned 14 ft from the device, to quantify spatial protection. Across both sites, the heat-activated volatile pyrethroid devices achieved the strongest and most consistent reductions in mosquito captures. At the urban site, the Dynatrap® and Thermacell devices lowered mean Aedes counts from all traps in all replicates 14.33 ± 2.05 in the control to 0.96 ± 0.27 and 0.88 ± 0.26, respectively, and reduced mean Culex counts from 8.83 ± 1.40 to 0.50 ± 0.21 and 1.00 ± 0.29, respectively. At the rural site, where Anopheles were predominant, these same devices decreased mean captures from 34.96 ± 7.20 in the control to 1.63 ± 0.49 (Dynatrap®) and 2.50 ± 0.63 (Thermacell®). Culex were reduced from 15.79 ± 2.91 to 2.63 ± 0.61 (Dynatrap®) and 4.00 ±0.69 (Thermacell®) at the same site. Dunnett's multiple comparisons confirmed that these were the only treatments to produce significant reductions across multiple genera at both sites. Mosquito coils offered moderate but inconsistent protection, while the citronella candle and ultrasonic device showed minimal or no measurable effect, aligning with previous findings that citronella‑based products provide little field efficacy. This characterization of "inconsistent" reflects the night‑to‑night fluctuations in percent reduction, which are evident in the raw data (not shown) and already conveyed in the reported means and confidence intervals. Together, these results demonstrate that heat‑activated volatile pyrethroid devices can deliver strong, broad‑spectrum spatial protection across ecologically varied environments. The study emphasizes the need for standardized, wind‑controlled field testing and highlights significant performance gaps among widely marketed consumer repellents. Given that spatial repellents are now formally recognized as a recommended intervention class in the 2025 WHO Guidelines, these performance gaps carry important public health implications, as inconsistent or underperforming products could undermine the protective value expected from this intervention category.
Hierodula is a morphologically conservative mantid genus with a complex taxonomic history and several problematic species-level concepts across its native and invaded ranges. In Iran, four nominal Hierodula species have historically been reported (H. macrostigmata, H. tenuidentata, H. transcaucasica, and "H. trimacula"), but their validity and distributions have remained uncertain due to overlapping diagnostic characters and limited molecular data. This study addresses these issues by reassessing all available Iranian material within an integrative framework. The revision combines: Morphological examination of type and non-type material from Iran, India, Pakistan, and Oman, including detailed study of external characters and male genitalia. Mitochondrial COI barcoding of Hierodula specimens from multiple Iranian provinces and Pakistan, analyzed with Bayesian inference, maximum likelihood, and model-based genetic distance estimation. Compilation and critical validation of distributional data from museum collections, literature, and iNaturalist records, followed by mapping in QGIS. Morphological comparisons show that the holotype of H. macrostigmata and recently collected southern Iranian specimens are indistinguishable from H. coarctata in forewing stigma, pronotal shape, and male genitalia, supporting their synonymy. COI phylogenies and TN93 genetic distances recover two deeply divergent, well-supported clades corresponding to H. coarctata and the H. tenuidentata complex, with minimal intraspecific divergence and no separation between Iranian "H. macrostigmata" and Indian/Pakistani H. coarctata. Re-examination of specimens and literature demonstrates that records of "Hierodula/Sphodromantis trimacula" from Iran lack verifiable material, while male genital characters place the species unambiguously in Sphodromantis and confirm its absence from the Iranian fauna. The integrative evidence indicates that only H. coarctata and H. tenuidentata are currently valid Hierodula species in Iran, with H. macrostigmata as a junior synonym of H. coarctata and previous Iranian reports of S. trimacula rejected. The clear molecular separation between H. coarctata and the H. tenuidentata complex, combined with broad morphological variability in traits such as forefemoral spine coloration, underscores the need to abandon historically overemphasized colour characters and highlights the utility of COI barcoding in resolving conservative mantid lineages. Remaining uncertainty regarding the status of H. transcaucasica versus H. tenuidentata at a broader Eurasian scale calls for a forthcoming multi-locus, range-wide revision to formally resolve their taxonomy.
Over the last four decades, the red palm weevil (RPW), Rhynchophorus ferrugineus, has emerged as one of the most destructive pests of date and ornamental palms worldwide, causing major economic losses, with insecticide susceptibility strongly influenced by nutritional status. This study assessed how feeding versus starvation affects the sensitivity of RPW larvae and adults to ten commonly used insecticides at three dose levels (½×, 1×, and 2× of the recommended rate). Mortality rates were recorded and compared between fed and unfed insects. Starvation significantly increased mortality, particularly in larvae, which were consistently more vulnerable than adults. Voliam Flexi achieved complete mortality under both conditions, whereas Coragen, Cyprone, and Indocarb caused full larval mortality only under starvation at the highest dose. In adults, 100% mortality with Medprid, Sivanto, Fiprol, and Deciban occurred only in starved insects. Feeding reduced insecticide toxicity, likely via enhanced detoxification or dilution of toxins through ingested sap, as indicated by lower LC₅₀ values in unfed insects for Sivanto, Coragen, Fedothrin, and Lamdoc. These findings highlight feeding status as a critical determinant of insecticide efficacy. Pre-treatment starvation or natural food scarcity can enhance chemical performance, reduce insecticide use, and improve integrated pest management (IPM) strategies. The study also emphasizes the need for further research to elucidate the physiological mechanisms linking nutrition, detoxification, and insecticide susceptibility in RPW." and confirmed as accurate.
Urban landscapes are increasingly recognized as key arenas for biological invasions, yet the mechanisms enabling the local coexistence of multiple highly invasive species remain poorly understood. Urban habitat fragmentation generates mosaics of habitat patches that differ in size, isolation, and microhabitat complexity, shaping ant community structure and competitive interactions. Here, we investigated ant assemblages across a mosaic of urban habitat patches within a university campus in Buenos Aires, Argentina, focusing on four globally invasive ant species (Wasmannia auropunctata, Linepithema humile, Nylanderia fulva, and Solenopsis invicta) near the southern limit of their native ranges. We quantified species richness, abundance and composition using pitfall traps and evaluated species-specific indicators of food discovery, recruitment, and dominance using standardized bait experiments. Ant assemblages differed significantly among habitat patches, with marked spatial variation in richness, diversity, and species composition. Contrary to expectations of rigid dominance hierarchies, no single species consistently dominated across patches. Nylanderia fulva showed the highest numerical abundance and discovery efficiency, L. humile exhibited the strongest recruitment ability, and W. auropunctata displayed localized dominance near nesting areas, while S. invicta was rare and competitively subordinate. Ordination and multivariate analyses indicated strong spatial structuring of assemblages, consistent with the influence of urban fragmentation and patch-level heterogeneity. Overall, our results support a metacommunity perspective in which invasive ant coexistence in urban systems is mediated by context-dependent competitive interactions rather than fixed dominance hierarchies. By emphasizing the role of fine-scale spatial structure, this study provides a nuanced, system-specific contribution to understanding invasive ant dynamics in urban environments.
Cotton jassids (Amrasca biguttula) have emerged as the most damaging sucking pest in cotton production in Tanzania, causing yield losses of up to 50% when unmanaged. Control has largely depended on synthetic insecticides; however, their effectiveness has been questioned by growers. It remains unclear whether this reduced efficacy is due to inherent properties of the insecticides or to external factors such as application rate, timing, and method. Replicated field experiments were conducted at three locations within the Western and Eastern Cotton Growing Areas (WCGA and ECGA) of Tanzania during the 2024-2025 growing season. Four commonly recommended insecticides: Lambda-cyhalothrin, Chlorpyrifos, Imidacloprid, and Profenofos were evaluated alongside an untreated control using a randomised complete block design (RCBD). Applications were based on the economic threshold level (ETL = 1-2 jassids per plant) at 10 -14 day intervals. Mortality was assessed at 24, 48, and 72 hours post-application, and population reduction was calculated using Abbott's formula. Data were analysed using analysis of variance (ANOVA), with means separated using Duncan's Multiple Range Test (DMRT) at 95% confidence. All tested insecticides significantly reduced both nymph and adult jassid populations compared to the control, although their efficacy varied. Imidacloprid was the most effective, achieving mean reductions of 67.59% (nymphs) and 66.31% (adults), followed by profenofos with reductions of 52.75% (nymphs) and 55.83% (adults). The results demonstrate that insecticide effectiveness varies considerably, with Imidacloprid showing superior performance under field conditions. These findings suggest that its inclusion in integrated pest management (IPM) programmes could improve jassid control. However, optimisation of application practices remains essential to enhance overall efficacy and sustainability.
In 2025, a swarm of giant honey bees, Apis dorsata dorsata, was detected on board a cargo vessel prior to arrival at the port of Elizabeth, New Jersey, USA. Apis dorsata is a quarantine species not native to the United States, and further inspection of the bees uncovered 28 mites that were identified as Tropilaelaps mercedesae by morphological and DNA barcoding analysis. Tropilaelaps mercedesae is an ectoparasite of honey bees that is not yet present in the USA. An additional mite species, Kuzinia morsei, was also observed. Molecular screening of common honey bee pathogens in 42 intercepted bees showed a 5% prevalence of trypanosomatid infections and a 2% prevalence of American foulbrood. Additionally, Black queen cell virus (BQCV) and Deformed wing virus B (DWV-B) were detected in 38% and 7% of the samples, respectively. To our knowledge, this is the first detection of T. mercedesae and K. morsei on a vessel bound for the USA, as well as the first interception of a whole swarm of A. dorsata dorsata. Phylogenetic analysis of the CO1 sequence data indicated that the intercepted bee swarm originated from a southern India lineage. Our findings indicate that exotic bee swarms can harbor parasitic mites and multiple bee pathogens, both critical to the apiculture industry. Additionally, our findings reveal that Tropilaelaps mites can survive extended periods associated with adult bees and in the absence of brood, suggesting greater potential for long-distance movement and introduction risk. This study provides new insights into Tropilaelaps dispersal and swarm-mediated pathogen movement, thereby improving our ability to predict establishment and outbreak risk crucial for countering invasive agricultural threats. The findings also emphasize that early detection, through coordinated port and shipboard surveillance, and strong interagency collaboration, is vital for reducing the risk of agricultural pest and pathogen introductions into the USA.
Mosquito-borne diseases, such as malaria, dengue, and Zika, pose significant global health challenges, intensified by rising insecticide resistance and environmental concerns associated with conventional control methods. RNA interference (RNAi) offers a promising, eco-friendly, and species-specific approach for mosquito vector control by silencing critical genes. This study aims to assess the research landscape of RNAi in mosquitoes through a bibliometric analysis. Relevant publications from January 2010 to October 2025 were retrieved from the Web of Science and Scopus targeted RNAi-related keywords. Only peer-reviewed, English-language original research articles were included. Data were analyzed using VOSviewer for network visualization, Bibliometrix for bibliometric metrics, and Microsoft Excel for descriptive analysis. The analysis included 480 articles, revealing a steady increase in publications, with a peak in 2020. The United States (45.4%) and China (22.1%) led research output, while African countries were notably underrepresented. Keyword co-occurrence analysis indicated a shift from foundational gene function studies to applied technologies, including nanoparticle and yeast-mediated RNAi delivery systems. High-impact journals like Proceedings of the National Academy of Sciences and Parasites & Vectors were prominent publication venues. Most studies targeted several genes, with the majority in Aedes species, then Anopheles species, and the least Culex species. RNAi research in mosquitoes has advanced significantly, evolving toward practical vector control solutions, yet challenges persist in delivery efficiency and field application. The lack of African representation highlights the need for equitable global collaboration. Strengthened international partnerships and increased regional investment are essential to realize RNAi's potential for sustainable, effective mosquito control.
Under global warming, the frequency and severity of agricultural pest outbreaks have intensified, posing serious threats to agriculture. The green peach aphid (Myzus persicae (Hemiptera: Aphididae)), an important agricultural pest, exhibits green and red color morphs and differentiated thermal tolerance, yet the underlying molecular mechanisms remain unclear. In this study, based on transcriptome and 16S rDNA amplicon sequencing, we analyzed the gene expression patterns and microbial community dynamics of green and red morphs of M. persicae under high-temperature stresses (30 °C and 35 °C) and across different exposure durations, comparing their similarities and differences in heat-response processes. Principal component analysis of transcriptomic data indicated that temperature had a greater influence on the physiological responses of M. persicae than body color, with a more pronounced effect observed at 35 °C. Differential gene expression analysis revealed overlap in temperature-responsive genes but different response patterns between the two morphs, suggesting activation of divergent molecular response mechanisms. Genes encoding heat shock proteins, detoxification-related enzymes, ribosomal protein family and so on were significantly up-regulated under high temperature, with a more pronounced induction in the green morph, indicating morph-specific regulatory strategies in response to thermal stress. Moreover, 16S rDNA sequencing revealed that the primary symbiont Buchnera displayed different relative abundance trends in the green and red morphs, remaining relatively stable in the red morph but declining markedly in the green morph under heat stress, potentially associated with their variation in thermal tolerance. Collectively, this study elucidates the molecular responses and microbe-mediated regulatory mechanisms underlying thermal tolerance in green and red morphs of M. persicae, providing novel insights into the thermal adaptation of aphids and a theoretical basis for developing pest management strategies under global warming.
Several mosquito control technologies, including the sterile insect technique (SIT), the incompatible insect technique (IIT), and a variety of genetic technologies are emerging as promising solutions for combatting insecticide resistance and the spread of vector-borne diseases. These approaches involve mass releases of male mosquitoes in an effort to suppress mosquito populations in an eco-friendly manner. At small scale, male mosquito selection can be achieved through the use of mechanical separation techniques, but such methods are not sufficient for scaled implementation of emerging mosquito population control technologies. This review discusses mechanical, genetic, and automated mosquito sex sorting techniques that have emerged to address the need for scaled male mosquito production, as well as the potential contributions of RNA interference (RNAi) to facilitate this process. One RNAi method utilizes the oral delivery of yeast expressing interfering RNA targeting genes required for female larval survival. The yeast, which can be incorporated into normal insect larval diets, enables male sex selection during larval rearing in mosquitoes and could easily be extended to other insects. RNAi-mediated sex-sorting technologies, in combination with mechanical, genetic, and automated sorting technologies, could facilitate the scaled production of adult males in support of global insect population suppression efforts.
Migration plays an important role in the ecology of insect pests, including Helicoverpa zea, a major pest of multiple crops across the U.S. The long-standing "pied piper" hypothesis proposes that H. zea populations migrate northward each summer to exploit seasonal resources but because cannot overwinter in the lethal winter conditions, populations of this pest fail to continue to be established in higher latitudes in North America. This study investigated the natal origins and migratory connectivity of H. zea moths collected across Florida between 2017 and 2024 using stable hydrogen isotope analysis of wing tissues. Through this approach, we traced the origins of 249 individuals, revealing that most late-season moths originated locally or from southern U.S. regions. However, a distinct subset exhibited isotopic signatures indicative of long-distance migration from northern areas, including the upper Midwest and Corn Belt. Estimated flight distances for these northern migrants ranged from 1,375 to 1,725 km, with dispersal patterns showing a predominant northwest-to-southeast orientation. These findings provide evidence that H. zea populations engage in bidirectional migration. This H. zea reverse migration has critical implications for integrated pest management (IPM) and insect resistance management (IRM) to insecticides and Bt traits, considering the risk of gene flow of populations under continuous selection for resistance in both Cotton and Corn Belts.
In contrast to mammals, insects possess a separate machinery for processing of long dsRNAs into siRNAs for the cleavage of viral RNAs. The process of RNAi is considered very efficient in all insects once the delivery in the cytoplasm occurs such as during RNA virus replication. For the application of RNAi as insecticide to succeed, efficient uptake of intact dsRNA into the cytoplasm therefore is necessary, which seems to occur by natural mechanisms in the leaf beetles for which RNAi-based insecticides already have been marketed. In most insects, relatively high amounts of dsRNA are required to trigger gene silencing which raises questions regarding potential side effects. Besides, RNAi is considered as the major antiviral defense mechanism, at least in Drosophila, but not necessarily in all other insects. Following increasing evidence from the recent literature, it has become prudent to include the sensing of dsRNA as an immune trigger to evaluate the extent of the RNAi mechanism that is triggered by dsRNA. In this review, an overview of mechanisms is presented regarding how the recognition of dsRNA as a "pathogen-associated molecular pattern", the multiple additional functions of the canonical siRNA factors and the modulation of the function of Dicer-2 and Ago-2 by dsRNA-binding proteins may complicate the efficiency of the exo-RNAi process and aggravate its application for pest control.
The African sugarcane stalk borer (Eldana saccharina) is a major insect pest of sugarcane in Sub-Saharan Africa. Because its larvae reside inside sugarcane stalks, conventional measures are less effective. Poorly managed infestations can reduce sugar production by up to 18% from damage caused by a single larva. Limited knowledge on the genetic diversity and population structure of E. saccharina, has curtailed insights into developing breeding-based pest management strategies including host resistance. Samples of Eldana saccharina were collected from three altitude-defined agroecological zones in Tanzania. A mitochondrial cytochrome c oxidase subunit I (COI) region was amplified, sequenced, and analyzed to assess genetic diversity, population structure, and phylogenetic relationships among populations. Twelve unique haplotypes were identified. Observed haplotype diversity was high in the high altitude (Hd=0.64) and medium (Hd=1.00) populations, and moderate in the low-altitude populations (Hd=0.57), although these estimates should be interpreted cautiously due to the small sample size used. Overall genetic differentiation across populations was significant (χ² = 38, P = 0.017). Pairwise comparison showed significant differentiation between high and low altitude populations (FST = 0.35, P = 0.004) and between medium and low altitude populations (FST = 0.21, P = 0.01), whereas differentiation between high and medium altitude populations was low and not significant (FST = 0.1, P = 0.12) A significant positive Tajima's D value in the low-altitude (2.5, P = 0.01), may indicate possible population contraction or selection, although this inference is provisional due to limited sample size. The presence of geographically structured and zone-specific haplotypes was observed, suggesting preliminary altitude-associated genetic differentiations. E. saccharina populations in Tanzania showed substantial mitochondrial genetic diversity and altitude-associated population structure. These findings suggest preliminary basis for considering population variation in the design of locally relevant monitoring, host-resistance breeding, and other targeted pest management strategies.
Wolbachia-based vector control strategies have been successfully implemented as a sustainable long-term solution and a promising tool for controlling Aedes mosquitoes, primarily Ae. aegypti, the main vector of major arboviral diseases. Since it is essential to rear healthy and competent adult mosquitoes for mass release under Wolbachia-based vector control strategies, optimising larval diet is essential. Therefore, the current study tested and compared four different larval diets to examine their statistical significance on the Wolbachia transinfected and uninfected Ae. aegypti life table traits. We tested and compared the effects of four larval diets: LD1 (fish feed), LD2 (laboratory rodent diet), LD3 (mushroom powder), and LD4 (dog biscuit plus brewer's yeast) on hatchability, pupation, adult emergence, fecundity, and adult survival of Wolbachia-transinfected (wMel and wAlbB) Puducherry strains, as Among the tested diets, fish feed (LD1) and the combination of dog biscuit with brewer's yeast (LD4) have significant effects in both Wolbachia-transinfected and uninfected Ae. aegypti strains regarding egg hatchability, pupation, adult emergence, fecundity, and adult survival. The highest fecundity was observed under LD1 for uninfected Ae. aegypti, with approximately 84 eggs/female (84.0 ± 6.0), followed by wMel (Pud) mosquitoes (~78 eggs/female, 78.0 ± 5.2) and uninfected mosquitoes (~75 eggs/female,74.6 ± 23.3) under LD4 diet in the F0 generation. The uninfected Ae. aegypti females exhibited significantly lower mortality risk under LD2 (Hazard Ratio (HR)=0.56<1, P<0.001), with a high median survival of 57 days compared to all other diets. The results of this study suggest that LD1 (fish feed) can be recommended as the superior larval diet for the mass rearing of Wolbachia-transinfected strains, although both LD1 and LD4 diets demonstrated positive effects on all the Ae. aegypti strains. Meanwhile, LD4 (dog biscuit + brewer's yeast) can be recommended for the routine rearing of uninfected Ae. aegypti colonies, as it is comparatively cost-effective and readily available in India. These findings could contribute to the large-scale mosquito rearing programs under the Wolbachia strategy, ultimately supporting the implementation of sustainable vector control approaches for arboviral disease management.
Mosquitoes of the genera Anopheles, Culex, and Aedes are of major medical importance as vectors of malaria, filariasis, Japanese encephalitis, dengue, chikungunya, and Zika. Understanding their morphology and bionomics is fundamental for vector biology, ecological studies, and the design of effective control strategies. Laboratory colonies of mosquitoes serve as an indispensable resource for investigating mosquito genetics, physiology, and vector-pathogen interactions, while also enabling the evaluation of new interventions such as Wolbachia-based control and the sterile insect technique. This review synthesizes current knowledge on the morphology and bionomics of key mosquito vectors and outlines advances in colony establishment, rearing, and maintenance. Particular attention is given to larval and adult diet, environmental conditions, oviposition, blood-feeding methods, and strategies to minimize inbreeding and maintain microbial balance in colonies. Challenges including genetic drift, colony adaptation, and maintenance of representative field traits are discussed alongside emerging solutions. By integrating classical entomological knowledge with recent innovations in rearing technology, this review highlights the central role of sustainable mosquito colonies in strengthening basic research and supporting applied approaches for vector-borne disease control.
The volatiles from Mango tree play a critical role in mediating interactions with herbivores, including the mango pulp weevil (Sternochetus frigidus), a serious quarantine pest of mango. The monophagous feeding habit and concealed life cycle of mango pulp weevil within fruits render insecticides, quarantine measures and post-harvest treatments largely ineffective. Identifying volatile cues emitted by the mango tree that mediate host location can aid in developing eco-friendly management strategies. In this study, Volatile Organic Compounds (VOCs) from different mango tree parts viz., young flush, mature flush, stem, flower, stone, whole and sliced green fruits, whole and sliced ripened fruits were characterized through solvent extraction and Gas Chromatography-Mass Spectrometry (GC-MS). The behavioural responses of adults were evaluated through Y-tube olfactometer assays. Ripened mango fruits, young leaves and mango stone elicited the strongest responses and were further subjected to headspace volatile collection. Ripened fruit volatiles induced the highest levels of attraction (63.33%), activity (86.67%) and preference (46.15%). Young leaf volatiles induced moderate attraction (46.7%) with high activity (83.3% but low preference (12%). Mango stone volatiles, in contrast, evoked minimal activity (6.7%) and preference (10%). GC-MS profiling of headspace extracts revealed nine compounds each from ripened fruits and young leaves and seven from stones, with D-limonene, 3-carene and α-pinene dominating across all treatments. These findings highlight key VOCs associated with host selection by Sternochetus frigidus and provide a chemical basis for developing attractant-based trapping systems as components within a holistic Integrated Pest Management (IPM) approach in mango cultivation.
While biopesticides have been around for 70 years, starting with Bacillus thuringiensis bioinsecticides, they are experiencing rapid growth as the products have gotten better and more science-based and there are more restrictions on synthetic chemical pesticides. The growth of biopesticides is projected to continue to outpace that of chemical pesticides, with compounded annual growth rates of 10%-20% versus single digits for chemicals. When integrated into pest management programs, biopesticides offer the potential for higher crop yields and quality than chemical-only programs. Added benefits include the reduction or elimination of chemical residues, therefore easing export, delay in the development of resistance by pests and pathogens to chemicals, shorter field re-entry, biodegradability and lower carbon footprint and greenhouse gas emissions, and low risk to non-target organisms, including pollinators. However, many challenges still exist to drive further the adoption of biopesticides. These include lack of awareness and education in how to test and deploy their unique modes of action in integrated programs, resulting in lingering perceptions about performance and cost-effectiveness. This article addresses these issues with suggestions on how to increase farmer and key influencer confidence in the deployment of biologicals in integrated pest management (IPM) programs, including adjusting IPM thresholds and practice based on the modes of action of biopesticides compared to synthetic chemicals.