Medical and Veterinary Entomology

BackgroundAnopheles gambiae sensu lato (s.l.) is the primary vector of malaria in sub-Saharan Africa. Although insecticide-based vector control has been central to prevention, the widespread emergence of insecticide resistance poses a serious biological threat to control efforts. Effective resistance monitoring is essential for sustaining vector control but remains highly limited in malaria-endemic hotspots. Here, we assessed pyrethroid and DDT resistance intensity and the frequency of the L1014F knockdown resistance (kdr) mutation in Anopheles gambiae s.l. populations from Sokoto, north-western Nigeria. MethodologyResistance status and intensity to five insecticides were determined in adult Anopheles reared from larvae collected in 2021 and 2022 using the World Health Organization (WHO) tube test and Centers for Disease Control and Prevention (CDC) bottle bioassay, respectively. A subset of resistant mosquitoes was analyzed using PCR-based diagnostic assays to identify species within the Anopheles gambiae complex and to genotype for the West African kdr mutation (L1014F). ResultsHigh knockdown times (KDT) were observed, with KDT50 ranging from 38 to 91 minutes and KDT95 from 104 to 678 minutes, indicating increased resistance levels across all insecticides. In 2021, resistance was detected to DDT, lambda-cyhalothrin, and permethrin, while susceptibility to alpha-cypermethrin (98%) and suspected resistance to deltamethrin (91%) were recorded. In 2022, a general increase in resistance to all insecticides was observed, with mortality rates ranging from 41% to 81%. High resistance intensity was observed against DDT, while permethrin and alpha-cypermethrin exhibited low resistance intensity in both years, failing to reach 10x the diagnostic dose. Deltamethrin and lambda-cyhalothrin showed low to moderate resistance intensity. The 1014F kdr mutant genotype was widely distributed (68.1%) across species and years. Allele frequencies were higher in An. gambiae s.s. (0.83) than in An. arabiensis (0.71), with significant deviations from Hardy-Weinberg equilibrium (p < 0.05), except for An. gambiae s.s. in 2021 (p = 0.7). ConclusionThese findings reveal a concerning increase in key insecticide resistance among Anopheles populations in Sokoto, underpinned by strong genetic mechanisms. This underscores the urgent need for integrated vector management strategies to sustain effective vector control efforts in the region.

Combining novel methodologies with ovarian dissection, we estimated life histories for ca. 90,000 individual female Glossina pallidipes and G. m. morsitans sampled from 1988-1999 in Zimbabwes Zambezi Valley. Using temperature-dependent development rates we stepped back through each flys life, fixing dates of successive pregnancies, adult emergence, pupal period, pregnancy and oogenesis. This enabled modelling of relationships between wing and egg lengths, and conditions prevailing when these lengths were being determined. Egg lengths increased with maternal wing length, were shorter in primiparous flies but changed little with age thereafter. G. pallidipes egg lengths were positively related to NDVI and negatively to temperature (R2 = 0.68), for variables averaged over the period of oogenesis for each fly, and then averaged again across weekly cohorts of flies. G. m. morsitans mean egg lengths, pooled by month, showed the same pattern (R2 = 0.53). Pooled mean wing lengths increased with NDVI and decreased with temperature prevailing while flies were developing in the ovaries and uterus; R2= 0.66 (G. pallidipes) and R2= 0.56 (G. m. morsitans). The models - fitted using flies captured after November 1991 - gave good predictions, with no further modeling, for egg and wing lengths of flies captured between September 1988 and November 1991. The models facilitate true predictions of future changes in fly size based on readily available meteorological data, benefiting vector and disease control efforts in predicting likely changes in tsetse population densities and distribution. Selection against small individuals in the hot-dry season is not restricted to teneral mortality continuing for some weeks after emergence. NDVI, measures of wetness and temperature can indirectly impact tsetse size, mortality and population density by affecting vertebrate host density and, thereby, the probability of tsetse locating and feeding on a host. Our methodology impacts numerous areas of vector biology and control.

BackgroundThe malaria transmission potential and the vulnerability of Anopheles mosquitoes to different vector control methods depend, among other factors, on the endophily, endophagy, anthropophagy and survival of each species. Local information on these bionomic parameters is generally unavailable. MethodsTo address this, we estimated species-specific values of these parameters using an augmented version of the global database of bionomics data by Massey et al. (2016). We applied inclusion and exclusion criteria to select eligible studies with relevant experimental designs that minimise bias from collection methods for parous, sac, endophagy, and endophily rates as well as for the resting duration. For the human blood index (HBI), we separated data from indoor and outdoor collections. We fitted hierarchical Bayesian models with levels based on Anopheles taxonomy to estimate these quantities. Based on the estimated bionomics, we quantified the expected vectorial capacity reduction after the introduction of a pyrethroid-pyrrole insecticide-treated net (ITN) for 57 Anopheles species. ResultsWe identified 26 eligible studies for endophagy and 61 for the parous rate, leading to a Bayesian posterior average for the Anopheles genus of 42% (95% credible interval: 18-70) and 55% (32-77) respectively. HBI values widely varied depending on the location of collection, except for some species showing strong anthropophilic behaviours. Resting duration was estimated to be 2.1 days (1.2 - 4.8) at the genus level. Few studies were available to estimate the sac and endophily rates, which prevented us from deriving precise estimates for the whole Anopheles genus. Our estimates of the vectorial capacity reduction following the introduction of a pyrrole-pyrethroid ITN ranged between 48% and 76% across species, highlighting the important differences among mosquito species in vulnerability to vector control interventions. ConclusionThis work demonstrates how data from both Anopheles species complexes and individual species can be leveraged to generate species-specific estimates of bionomic parameters, capturing the local characteristics and behaviour of malaria vectors. The dataset is readily updatable as new data become available. However, more frequent and standardised field surveys are still needed to accurately characterise local vector behaviour.

Black soldier fly larvae (BSFL) have quickly become one of the most farmed animals in the world. However, little is known about how to monitor stress and welfare in these animals. The difficulty of welfare assessment is compounded by the fact that BSFL live in their feed and prefer darkness. This behaviour makes it challenging to observe potential welfare indicators without inducing stress via disturbing the larvae or moving them into the light. However, acoustic devices may be able to pick up signatures of stress in the population even while they are out of sight, allowing for remote monitoring of animals in natural conditions (in the feed and/or in the dark). Acoustic monitoring of this type has been deployed for the detection of insects in stored grains, suggesting this method holds some promise for assessing insect behavioural signatures. In this study, we aimed to identify general, acoustic signatures of stress in BSFL by recording them during exposure to two stressors (light or shaking) or in a low-stress control condition. Our data suggest there are consistent differences in the acoustic recordings of the non-stressed and stressed conditions that may indicate the animals behaviours shift consistently in response to stress. Ultimately, the data suggest acoustic monitoring may hold promise for larval behaviour and/or welfare assessment and should be further explored in response to a variety of stressors across the larval life stage.

BACKGROUNDThe two-spotted spider mite, Tetranychus urticae Koch, is a major agricultural pest with a rapid propensity for developing acaricide resistance. Bifenazate targets mitochondrial cytochrome b (CYTB). While the G126S mutation is frequently associated with resistance, its independent role remains unclear as it often occurs with other substitutions. This study explores the molecular basis of bifenazate resistance in a Russian laboratory strain derived from a St. Petersburg greenhouse population. RESULTSDisruptive selection with increasing bifenazate concentrations generated resistant and susceptible isofemale lines. AlphaFold2 structural modeling of CYTB indicated that G126S causes a steric clash, leading to conformational destabilization, whereas other reported mutations primarily affect the ligand-binding pocket. Oxford Nanopore sequencing revealed a very low initial frequency of the G126S allele (<1%; 226/35,895 reads) in the unselected population. After one year of stepwise selection (0.00005-0.031% a.i.), the mutant allele frequency surged to 90% (7,272/8,056 reads). No other known resistance-associated mutations were found in the analyzed cytb fragment. CONCLUSIONWe report the first identification of the G126S mutation in a Russian T. urticae population and demonstrate its rapid fixation under bifenazate selection. Within this genetic background, G126S alone appears sufficient to confer high-level resistance, emphasizing the population-specific nature of resistance evolution and the critical need for local monitoring.

Gastropods are a highly diverse and often overlooked taxonomic group of significant ecological and economic importance. Some terrestrial gastropods are critical pests of commercial agriculture and home gardens worldwide. Malacopathogenic nematodes offer an effective biological control method of managing pest slugs and snails as a natural enemy. Pellioditis (syn. Phasmarhabditis) hermaphrodita and Pellioditis (syn. Phasmarhabditis) californica are two species of biocontrol nematodes that have been commercialized, sold as Nemaslug(R) and Nemaslug(R) 2.0 respectively on three continents. Although there is interest in bringing Nemaslug(R) products to the US, they are currently not permitted due to limited knowledge on their North American distribution and effects on non-target and native species. In this study, we investigated the impact of P. hermaphrodita and P. californica on Ariolimax columbianus across two slug-host life stages, in laboratory infectivity assays. The objectives were to 1. determine whether P. hermaphrodita and P. californica nematodes impact survival of A. columbianus, and 2. evaluate whether there are differential effects on survival in juvenile and adult life stages of A. columbianus, in laboratory infectivity trials. We found that P. hermaphrodita caused significant mortality in A. columbianus with 100% mortality observed in both juvenile and adult slug hosts. The P. californica treatment had significant effects on the juvenile A. columbianus group only, with 80% mortality. By contrast, only 16% of unexposed control juveniles and 4% of control adult slugs died during the experiment. These results indicate that P. hermaphrodita and P. californica are lethal to the native, non-target Pacific banana slug (A. columbianus) under laboratory conditions, with mortality differing between juvenile and adult host life stages. Given the ecological importance of A. columbianus, these findings raise concerns for potential non-target effects of P. californica and P. hermaphrodita on terrestrial gastropod communities and emphasize the need for testing biocontrol agents against multiple life stages.

BackgroundAnopheles mosquitoes vector pathogens responsible for more than 600,000 human deaths annually. Ecological studies of these insects are important to guide effective vector-control campaigns and to understand their broader ecological consequences. Molecular ecology methods, particularly qPCR, provide a valuable tool in such studies. By detecting trace DNA of a taxon of interest within mixed or environmental samples, qPCR can facilitate identification of prey taxa of interest in the diets of consumers. However, no protocol for the detection of An. gambiae complex mosquitoes in dietary samples has been available. MethodsWe introduce a new set of qPCR primers (Agam_CO1_F1 and Agam_CO1_R1) and a probe-based assay for detection of Anopheles gambiae-complex mosquitoes, even with short reads common in dietary and environmental samples. The primers were tested in vitro for their specificity and sensitivity, and in silico using Primer-BLAST to assess potential off-target amplification. ResultsThe qPCR primers amplified An. gambiae DNA even at low starting concentrations (5 copies {micro}l-1). The primers did not amplify any non-target DNA in either the in vitro or in silico tests, but consistently amplified An. gambiae complex DNA. The primers can therefore provide reliable tests for the presence or absence of An. gambiae complex in dietary or eDNA samples. ConclusionsThe new qPCR primers should allow advances in research into mosquito ecology by allowing detection of even trace amounts of An. gambiae DNA in dietary and environmental samples. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=72 SRC="FIGDIR/small/707393v1_ufig1.gif" ALT="Figure 1"> View larger version (11K): org.highwire.dtl.DTLVardef@1fcce3corg.highwire.dtl.DTLVardef@47e5f5org.highwire.dtl.DTLVardef@4a7063org.highwire.dtl.DTLVardef@1188d60_HPS_FORMAT_FIGEXP M_FIG C_FIG

The tropical house cricket Gryllodes sigillatus is a major species used in the edible insect farming industry. Despite the rapid expansion of this sector, diagnostic tools for detecting infections in these species remain limited. The lack of validated reference genes compromises the reliability of RT-qPCR-based gene expression analyses, which are essential for the development of molecular tools for disease diagnosis and health monitoring in insect production systems. To address this gap, we evaluated the expression stability of six candidate reference genes (ACTB, EF1, GAPDH, HisH3, RPL5, and 18SrRNA) across four body parts (abdomen, head, legs, and whole body) using a combination of complementary statistical approaches, including geNorm, NormFinder, BestKeeper, the {Delta}Ct method, the R statistical environment, and the integrated RefFinder tool. Candidate genes were identified and annotated using the recently published G. sigillatus genome, through sequence comparisons with closely related insect species using BLAST and reciprocal BLAST analyses, multiple sequence alignments. All procedures complied with MIQE 2.0 guidelines to ensure methodological rigor and transparency. The results showed that ACTB, EF1, RPL5, and 18SrRNA exhibited stable and consistent expression across all analyzed tissues, whereas GAPDH and HisH3 displayed high variability and were generally unsuitable for normalization, except in head tissue where GAPDH remained stable. This study provides the first validated set of reference genes for G. sigillatus, establishing a robust foundation for accurate, reproducible, and comparable gene expression analyses. Furthermore, these findings support the development of RT-qPCR-based diagnostic tools, contributing to improved health monitoring and biosafety in insect production systems.

The wMel strain of the insect endosymbiont Wolbachia reduces the potential for Aedes aegypti to transmit mosquito-borne viruses such as dengue (DENV). Field trials that have introgressed wMel into Ae. aegypti populations have shown this approach significantly reduces dengue incidence. In a laboratory setting some wMel-Ae. aegypti develop infectious saliva following a viremic blood meal. Additionally, studies have demonstrated that exposing wMel-Ae. aegypti to heat treatment, particularly during the larval stage, reduces wMel density in key tissues such as the ovaries, midgut and salivary glands. Here we build on these studies, using viremic blood collected from 13 dengue inpatients at the Hospital for Tropical Diseases in Ho Chi Minh City (Viet Nam), to assess how temperature affects the protection afforded to Ae. aegypti by wMel. We found that, compared to wMel-Ae. aegypti reared at 28 {+/-} 4{degrees}C, those reared at 31 {+/-} 4{degrees}C developed infectious saliva more frequently, but the risk of this occurring was still reduced compared to WT mosquitoes reared at the same temperature. Heat treatment reduced the density of wMel in all tissues tested, decreased the magnitude of wMels protection against DENV replication in the head/thorax, and significantly increased the amount of DENV replication in wMel-Ae. aegypti. When comparing cohorts of wMel-Ae. aegypti that did or did not develop infectious saliva, DENV levels in the head/thorax were associated with increased odds of mosquitoes developing infectious saliva, but wMel density was not. Overall, these findings show that elevated rearing temperatures increase the risk of patient-derived DENV breakthrough infections in wMel-Ae. aegypti, potentially due to increased DENV replication in these mosquitoes. This limitation suggests it would be prudent to increase surveillance in regions using wMel for dengue control when daily mean temperatures remain above 30{degrees}C for multiday periods. Author SummaryThe mosquito species Ae. aegypti can be infected with the bacterium Wolbachia (wMel strain), reducing its capacity to transmit viruses like dengue (DENV). Wolbachia is now being used as a biocontrol tool to reduce the burden of dengue in communities. However, some mosquitoes with Wolbachia can still transmit DENV. Here we utilised a natural infection model using dengue patient-derived blood to examine how temperature may increase the risk of DENV transmission occurrence in mosquitoes with wMel. Mosquitoes with wMel were more likely to transmit virus when reared at an average temperature of 31{degrees}C compared to those reared at an average temperature of 28{degrees}C but these mosquitoes still had a lower risk of developing infectious saliva compared to their wMel-free counterparts. Higher temperatures reduced the amount of wMel in mosquito tissues and increased the amount of DENV replicating in the head/thorax. Increasing levels of DENV RNA in these tissues were found to be associated with increased risk of mosquitoes with wMel developing infectious saliva. This finding indicates surveillance is warranted in high temperature settings or during heat waves, to monitor for changes in wMel frequency and DENV infection in Ae. aegypti.

Accurate species identification is crucial to assess the medical and veterinary relevance of a mosquito specimen, but it requires high experience of the observers and well-equipped laboratories. This study aimed to evaluate whether low-cost imaging in combination with geometric wing morphometrics can provide accurate identification of invasive, morphologically similar Aedes species. The right wings of 670 female specimens covering 184 Ae. aegypti, 156 Ae. albopictus, 166 Ae. j. japonicus and 164 Ae. koreicus, were removed, mounted and photographed with a professional stereomicroscope (Olympus SZ61, Olympus, Tokyo, Japan) and a macro lens (Apexel-24XMH, Apexel, Shenzhen, China) attached to a smartphone. The coordinates of 18 landmarks on the vein crosses were digitalized by a single observer for each image. In addition, the landmarks of 20 specimens per species and imaging device were digitalized by six different observers to assess the degree of the observer error. The superimposed shape variables were used to compare the species classification accuracy of linear discriminant analysis (LDA), support vector machine (SVM), Random Forest (RF), and XGBoost. In the single-observer landmark data, the LDA achieved the best classification results with a mean accuracy of 95 % for landmarks from microscope images and 92 % for those obtained from smartphone images. In the multi-observer landmark data, LDA consistently performed worse than the other three classifiers, and the reduction in the accuracy was more pronounced for smartphone images than for microscope images. This pattern was associated with a higher degree of observer error for smartphone images, as confirmed by a landmark-wise comparison across all landmarks. Geometric wing morphometrics provides a reliable method to distinguish the most common invasive Aedes species in Europe. Thereby, the image quality obtained by smartphones equipped with a macro lens is sufficient and represents a cost-effective alternative to professional microscopes. However, due to the greater degree of observer variation for smartphone images, landmark coordinates for such images should ideally be collected by a single observer.

The ichneumonid subfamily Eucerotinae has been thought to be almost absent from the tropics, with the only known Afrotropical species found in Madagascar. We report the subfamily to be present in the mainland Afrotropics, and describe a new species, Euceros species 1 from Uganda and Cameroon (name not yet shown in preprint). The subfamily had likely not been observed in the mainland Afrotropics before due to low abundances and insufficient sampling. More Eucerotinae likely remain to be discovered in tropical Africa and Asia, although tropical America may genuinely have few eucerotine species. Much more extensive sampling will be needed before it is possible to make confident estimates of how eucerotine diversity is distributed globally.

Understanding how fruit fly species partition resources along environmental gradients is important for predicting pest pressure under changing climatic conditions. The population ecology of Dacus bivittatus (Bigot) and Dacus punctatifrons (Karsch) (Diptera: Tephritidae) was examined across six sites spanning 526-1,650 m above sea level in the Uluguru Mountains, Tanzania, over eight years (2004-2012). A total of 2,200 weekly trap records were aggregated into 292 site-month observations and standardised as flies per trap per day (FTD). Dacus bivittatus showed strong seasonal structuring (H = 43.03, p < 0.001), with abundance peaking during the cool dry season (June-August), whereas D. punctatifrons showed no clear seasonal pattern. Both species declined significantly with increasing altitude ({rho} = -0.308 and -0.769, respectively; p < 0.001), but the decline was steeper for D. punctatifrons. Species dominance shifted along the gradient: D. punctatifrons dominated warm lowland conditions (>24 {degrees}C), whereas D. bivittatus prevailed at elevations above approximately 569 m. Seasonal niche overlap declined markedly with altitude, indicating increasing temporal segregation between the species in cooler environments. These findings demonstrate that altitude structures ecological divergence between two closely related fruit fly pests and provide a basis for site-specific monitoring and climate-sensitive pest forecasting in tropical mountain agroecosystems.

Understanding how vector ecology intersects with host behaviour is essential for predicting zoonotic disease risk in tropical ecosystems. We conducted a two-year field study (November 2016-October 2018) in a riverine forest in Sabah, Malaysian Borneo, to characterize mosquito communities and the spatial distribution of potential simian-malaria vectors. Mosquitoes were sampled on 44 nights using CO{square}-baited light traps repeatedly deployed along a 500 m transect at three distances from the river (0, 250, 500 m) and two vertical strata (ground and canopy), yielding 244 trap collections across repeated sampling nights. In total, 9,928 mosquitoes were collected, dominated by Culex spp. (9,079; 91.4%), whereas Anopheles spp. were rare (153; 1.5%); most remaining specimens were unidentified to genus, and species-level identification was limited primarily to Anopheles. Nevertheless, female Anopheles (n=57) were more frequently detected near the river and less commonly at intermediate distance, and tended to be captured more often in ground traps. Zero-inflated negative binomial GLMMs based on the full mosquito dataset indicated significant effects of river distance and height on mosquito abundance, while night-time temperature and humidity showed no detectable effects. The zero-inflated structure of the data further suggested that many zero captures reflected true absence rather than sampling variability. The Anopheles assemblage was dominated by An. balabacensis, and molecular screening of 57 females detected simian Plasmodium DNA in two individuals. Overall, these findings suggest that river-edge habitats may represent localized areas where vectors persist and where primates and human activities overlap, creating repeated opportunities for host-vector contact even when vector densities are low.

Ultra-low volume (ULV) insecticide spraying with deltamethrin as the active ingredient is widely used in mosquito control programs, yet its effectiveness against target mosquitoes and its ecological side effects remain poorly quantified under field conditions in Central Europe. Here, we experimentally evaluated the short-term impact of ground ULV spraying on both mosquito populations and non-target flying insects in Hungary using a paired before-after-control-impact (BACI) design. Mosquitoes were sampled with BG Sentinel traps, while non-target insects were collected using malaise traps. ULV treatment resulted in a significant reduction in mosquito abundance at treated sites, with an average decline of approximately 45%. Native and invasive mosquito species, including Aedes albopictus and Aedes koreicus, showed similar proportional decreases. However, treatment effectiveness varied substantially among sites and was influenced by initial mosquito abundance and wind conditions. In parallel, malaise trap samples revealed a marked decline in non-target flying insects, with reductions exceeding 40% across multiple taxonomic groups, particularly among small- and medium-sized insects, and also when considering pollinator taxa together. Our results indicate that while ULV spraying can temporarily reduce mosquito abundance, it also imposes considerable short-term impacts on non-target insect communities, highlighting trade-offs between vector control and insect conservation within mosquito management programs.

Tickborne diseases are a significant burden in many parts of the world. In the upper Midwestern United States, Lyme disease is the most common tickborne disease. It is carried by Ixodes scapularis. This vector can also transmit the pathogens causing anaplasmosis, babesiosis, ehrlichiosis, and several more tickborne diseases in this region. There is also concern for other tick species, such as Amblyomma americanum, that are expanding their ranges northward. We launched a citizen science passive tick surveillance program in 2024 to investigate tick species ranges in the upper Midwest, as well as the pathogens carried by I. scapularis. We received over 12,000 ticks in the first two years of this program, primarily from Wisconsin. While we received submissions of adult A. americanum outside of their endemic range, we did not see evidence of establishment in our study area. We measured pathogen prevalence in adult female I. scapularis (n=707) and observed 51% positivity for Borrelia burgdorferi, 9% for Babesia microti, 9% for Anaplasma phagocytophilum, and 3% for Ehrlichia muris eauclairensis. Multiple pathogens were identified in 14% of tested specimens, and significant associations were observed between B. burgdorferi and B. microti, and B. burgdorferi and E. muris eauclairensis. Pathogen prevalences varied across time and geography. Our results can begin to inform risk assessment for tickborne diseases in our region. A non-technical version of this document with interactive maps is available here: https://storymaps.arcgis.com/stories/8008c9d710b5400599f3c6cf88b2c546 Our online data dashboard is available here: redcap.link/TICS

BackgroundAnopheles stephensi, an invasive malaria vector originally endemic to South Asia, has rapidly expanded across East Africa. Its emerging malaria threats in urban Ethiopia threaten the elimination efforts, especially in areas once deemed low risk. A systematic review was conducted to synthesize the evidence regarding its bionomics and epidemiological impact, highlighting implications for urban malaria control strategies. This systematic review provides the first Ethiopia-specific quantitative evidence synthesis, addressing a vital knowledge gap necessary for guiding national malaria elimination programmes. MethodsWe conducted a PRISMA 2020-compliant systematic review and meta-analysis registered with PROSPERO (CRD420251176953). Searches of PubMed, Scopus, Web of Science, and regional repositories (2016-February 2026) identified studies reporting An. stephensi bionomics and epidemiological role in Ethiopia. Eligible studies required [&ge;]50% quality score on JBI appraisal tools. Random-effects meta-analysis estimated pooled proportions of An. stephensi among total Anopheles, with subgroup analyses by geography, habitat, and behavioural traits. Publication bias was assessed using Eggers and Beggs tests. ResultsEighteen studies (9 epidemiological, 11 bionomical) met inclusion criteria. The pooled proportion of An. stephensi was 0.51 (95% CI: 0.28-0.75) in epidemiological studies and 0.46 (95% CI: 0.26-0.66) in bionomics studies, with extreme heterogeneity (I{superscript 2} > 99%). Geographic analysis indicated significant variation: south-eastern Ethiopia showed a dominance of 0.73 (95% CI: 0.28-1.18) and eastern Ethiopia 0.57 (95% CI: 0.32-0.82), while central Ethiopia remained lower at 0.13 (95% CI: 0.12-0.14). These findings demonstrate genuine ecological differences rather than methodological objects, with substantial implications for region-specific vector management strategies. Extreme heterogeneity reflected genuine ecological variation across Ethiopia. No evidence of publication bias was detected. ConclusionAn. stephensi has very rapidly emerged as a major malaria vector in Ethiopia, with pooled proportions increasing from <10% at first detection (2016) to 51-73% in recent surveys (2024-2025), suggesting ongoing vector displacement parallel to invasion patterns documented in Djibouti. Geographic stratification indicates an urgent need for region-specific urban vector management integrating larval source management, resistance monitoring, and community engagement, particularly in south-eastern Ethiopia, where near-complete vector replacement has occurred. Author SummaryMalaria is usually thought of as a rural disease, but a new mosquito species called An. stephensi is changing that picture in Ethiopia. Originally found in South Asia, this mosquito has spread quickly across East Africa and is now common in Ethiopian towns and cities. We reviewed and combined results from published studies to understand how this species behaves and how much it contributes to malaria transmission. Our analysis shows that An. stephensi has become one of the dominant malaria vectors in several regions of Ethiopia, especially in the east and south-east, where it has almost replaced other mosquito species. This rapid change means that malaria risk is increasing in urban areas that were previously considered low risk. These findings highlight the urgent need for new control strategies that focus on city environments, such as managing breeding sites, monitoring insecticide resistance, and involving communities in prevention efforts. By understanding how An. stephensi is spreading and adapting, we can better protect urban populations and support Ethiopias malaria elimination goals.

RNA viruses are common in tephritid fruit flies including the Queensland fruit fly, Australias most significant horticultural pest. For many their transmission, tissue tropism and load across host development remain unexplored. Yet these factors are important for host biology, ecology and pest management. We investigated Bactrocera tryoni orbivirus (OV), Bactrocera tryoni xinmovirus (XV), Bactrocera tryoni toti-like virus (TLV) and Bactrocera tryoni iflavirus species 2 (IVsp.2) that commonly coinfect B. tryoni laboratory populations. OV and XV transmission was vertical within and on eggs, while TLV transmission was vertical within eggs. IVsp.2 was not detected in eggs but was present in adults; however, IVsp.2 was horizontally transmitted, with viral load increasing with cohabitation time with infected flies. Horizontal transmission was not observed for the other viruses. OV had a similar load across all tissues, while XV was consistently more abundant in ovaries. TLV had a high viral load in the brain whereas IVsp.2 was abundant in the thorax, foregut and midgut. Besides differences in eggs, the viruses were detected in all other developmental stages, but viral load patterns differed: viral load remained constant for TLV, fluctuated for OV and XV, and was low in pre-adult stages and high in adults for IVsp.2. Our findings demonstrate distinct transmission strategies and tissue tropism among the viruses, providing new insights into their epidemiology and role in host biology. Furthermore, contrary to prevailing views that viruses are generally horizontally transmitted, most known RNA viruses of B. tryoni are vertically transmitted affecting the evolution of host-virus interactions.

The black soldier fly, Hermetia illucens, is increasingly valued in applied entomology due to its remarkable capacity to upcycle organic waste and for high nutritional value of its larvae. As a result of global expansion and domestication, the species now displays substantial genetic diversity, yet performance differences between strains remain poorly documented. This study aimed to better understand the relationship between genotype and phenotype, as well as their interaction, to support the improvement of its domestication. Five distinct strains collected from the wild by artisanal farmers or obtained from industrial farms were genetically characterized using whole genome sequencing. These analyses revealed high genetic divergence based on mitochondrial genome and SNP nuclear genome phylogeny. To assess phenotypic performance, the strains were reared on three diets differing in nutritional value: poor (alfalfa meal), intermediate (wheat bran) and rich (chicken feed) and their growth rate was assessed. At harvest, we evaluated different life history traits including survival rate, average larval mass, feed conversion ratio, substrate reduction and bioconversion rate. Statistical analyses revealed strong effects of both diet and strain (p < 0.001), but the key result was the pronounced strain x diet interaction. Performance varied drastically depending on substrate quality: some strains showed high versatility across all diets, while others performed mainly on nutrient-rich substrates or excelled in substrate degradation. In contrast, other strains displayed more specialized profiles, with marked sensitivity to fibrous diets. These contrasted reaction norms highlight that diet performance cannot be interpreted independently of the strain genetics. Overall, these findings underscore the value of preserving diverse local genetic resources and the need for improved molecular tools to guide strain selection. ImplicationThis study shows that performance of the black soldier fly depends strongly on interactions between genetic background and diet, confirming the importance of genotype-environment relationships. While results are based on a limited number of strains and substrates, the consistent strain x diet interaction suggests broader relevance for rearing systems. These findings highlight the need to integrate genomic data into phenotypic assessments. Practically, they indicate that strain selection should be tailored to substrate type to optimize productivity and efficiency. This has direct economic benefits for insect farming and waste management industries because improved strain-diet matching can enhance organic waste bioconversion and support circular economy strategies. Overall, preserving genetic diversity and developing molecular tools for strain selection are key steps toward more sustainable and efficient insect production systems of this study have implications for the development and sustainable BSF systems production.

Introduced to Hawaii in 2016, Lema equestris has become a garden pest commonly reported on Solanum americanum, which is grown as a native and cultural plant in Hawaii and supports native vertebrates elsewhere across Oceania. Originally identified as L. solani, the species was later found to have been misidentified. Here, molecular and morphological evidence is used to discriminate Hawaiian specimens from L. solani and support the updated identification of L. equestris. As a new invasive species, it is important to confirm host associations and determine whether it will prey on important species, such as endemic or endangered plants, in its new range or any potential range to which it could spread. To this end, feeding assays were performed with adults, first-instar larvae, and newly hatched naive larvae on 11 potential hosts, comprising mostly Solanum species: Solanum americanum, potato, tomato, tomatillo, poha (gooseberry), chili pepper, eggplant, tobacco, tree tobacco, cabbage, and Brazilian nightshade. While feeding was attempted on cabbage, poha berry, and Brazilian nightshade, no host besides S. americanum supported survival. Rearing was used to further characterize the biology and life history of L. equestris, including instar length and distinctive morphological traits for identifying each life stage. While many basic biological traits are confirmed here, much remains to be studied to better understand this species and why it has begun to spread.

Some Anopheles species that act as malaria vectors are members of species complexes, a concept whereby sibling species cannot be differentiated solely on the basis of morphological characters. Therefore, species complexes represent a major problem in malaria vector control, because within an Anopheles complex, vectors cannot be differentiated from non-vector species, unless molecular techniques are used to identify them. The Anopheles tessellatus species complex is an important potential vector in South, East, and Southeast Asia, including certain regions of Indonesia. However, no in-depth studies have been conducted on this species complex in that country. Therefore, this study investigated the taxonomic status of An. tessellatus from diverse populations across five Indonesian islands (Sumatra, Java, West Nusa Tenggara, East Nusa Tenggara, and Sulawesi) and identified interpopulation genetic variation based on molecular data of the ITS2, COI, and COII genes. Phylogenetic relationships were constructed using the Maximum Likelihood method. Haplotype and network analysis were also conducted. The results indicate that An. tessellatus constitutes a monophyletic group comprising three well-defined lineages that exhibit clear intraspecific genetic differentiation. Cluster 1 corresponds to the population of Sumatra, Cluster 2 represents population from Sulawesi, and Cluster 3 encompasses populations from Java, West Nusa Tenggara, and East Nusa Tenggara. These findings demonstrate high haplotype diversity and low nucleotide diversity within the species. Populations from West Sumatra, Manado, Tojo Una - Una, and North Morowali (Sulawesi) have the potential for speciation with a genetic distance of 0.61 - 0.94% for COI, between 0.81 - 0.95% for ITS2, and between 0.62 - 0.71% for COII. These findings underscore the need for further integrative studies to obtain a more comprehensive understanding of the An. tessellatus complex in Indonesia and its role in malaria transmission.