Background: The combination ofWolbachia-based incompatible insect technique (IIT) and radiation-based sterile insect technique (SIT) can be used for population suppression ofAedes aegypti. Our main objective was to evaluate whether open-field mass-releases ofwAlbB-infectedAe.aegyptimales, as part of an Integrated Vector Management (IVM) plan led by the Mexican Ministry of Health, could suppress natural populations ofAe.aegyptiin urbanized settings in south Mexico.Methodology/Principal findings: We implemented a controlled before-and-after quasi-experimental study in two suburban localities of Yucatan (Mexico): San Pedro Chimay (SPC), which received IIT-SIT, and San Antonio Tahdzibichén used as control. Release ofwAlbBAe.aegyptimales at SPC extended for 6 months (July-December 2019), covering the period of higherAe.aegyptiabundance. Entomological indicators included egg hatching rates and outdoor/indoor adult females collected at the release and control sites. Approximately 1,270,000 lab-producedwAlbB-infectedAe.aegyptimales were released in the 50-ha treatment area (2,000wAlbBAe.aegyptimales per hectare twice a week in two different release days, totaling 200,000 male mosquitoes per week). The efficacy of IIT-SIT in suppressing indoor femaleAe.aegyptidensity (quantified from a generalized linear mixed model showing a statistically significant reduction in treatment versus control areas) was 90.9% a month after initiation of the suppression phase, 47.7% two months after (when number of released males was reduced in 50% to match local abundance), 61.4% four months after (when initial number of released males was re-established), 88.4% five months after and 89.4% at six months after the initiation of the suppression phase. A proportional, but lower, reduction in outdoor femaleAe.aegyptiwas also quantified (range, 50.0–75.2% suppression).Conclusions/Significance: Our study, the first open-field pilot implementation ofWolbachiaIIT-SIT in Mexico and Latin-America, confirms that inundative male releases can significantly reduce natural populations ofAe.aegypti. More importantly, we present successful pilot results of the integration ofWolbachiaIIT-SIT within a IVM plan implemented by Ministry of Health personnel.

The sterile insect technique (SIT) and its related technologies are considered to be a powerful weapon for fighting against mosquitoes. As an important part of the area-wide integrated pest management (AW-IPM) programs, SIT can help reduce the use of chemical pesticides for mosquito control, and consequently, the occurrence of insecticide resistance. The mosquito SIT involves several important steps, including mass rearing, sex separation, irradiation, packing, transportation, release and monitoring. To enable the application of SIT against mosquitoes to reduce vector populations, the Joint Food and Agriculture Organization of the United Nations (FAO) and the International Atomic Energy Agency (IAEA) Centre (previously called Division) of Nuclear Techniques in Food and Agriculture (hereinafter called Joint FAO/IAEA Centre) and its Insects Pest Control sub-program promoted a coordinated research project (CRP) entitled “Mosquito handling, transport, release and male trapping methods” to enhance the success of SIT. This article summarizes the existing explorations that are critical to the handling and transporting of male mosquitoes, offers an overview of detailed steps in SIT and discusses new emerging methods for mosquito releases, covering most processes of SIT.

The sterile insect technique is based on the overflooding of a target population with released sterile males inducing sterility in the wild female population. It has proven to be effective against several insect pest species of agricultural and veterinary importance and is under development forAedesmosquitoes. Here, we show that the release of sterile males at high sterile male to wild female ratios may also impact the target female population through mating harassment. Under laboratory conditions, male to female ratios above 50 to 1 reduce the longevity of femaleAedesmosquitoes by reducing their feeding success. Under controlled conditions, blood uptake of females from an artificial host or from a mouse and biting rates on humans are also reduced. Finally, in a field trial conducted in a 1.17 ha area in China, the female biting rate is reduced by 80%, concurrent to a reduction of female mosquito density of 40% due to the swarming of males around humans attempting to mate with the female mosquitoes. This suggests that the sterile insect technique does not only suppress mosquito vector populations through the induction of sterility, but may also reduce disease transmission due to increased female mortality and lower host contact.

Background: Aedes aegypti , the principal vector of dengue and other arboviruses, is widely distributed in Pakistan, yet its population genetics and endosymbiont status remain poorly characterized. This study aimed to investigate the genetic structure, haplotype diversity, and phylogeographic patterns of Ae. aegypti in dengue-endemic regions of Pakistan, and to screen for natural Wolbachia infections to provide baseline data for surveillance and vector control. Methods: Ovitrap collections were conducted in 2021 across the provinces of Punjab (Bakkar) and Khyber Pakhtunkhwa (Charsadda, DI Khan, Kohat, and two sites within Peshawar: Hayat Abad and Tarnab). Following the morphological identification of adult Ae. aegypti , we extracted genomic DNA from confirmed specimens to amplify and sequence a 658-bp fragment of the mitochondrial cytochrome c oxidase I ( COI ) gene. Phylogenetic analyses, haplotype network construction, and population differentiation statistics were performed. Additionally, 300 field-caught adult mosquitoes were screened for Wolbachia using validated conventional and quantitative PCR assays targeting the Wolbachia surface protein ( wsp ) gene. Results: Phylogenetic analysis of 166 COI sequences (92 from Pakistan) revealed a monophyletic Ae. aegypti clade with 99.65–100% sequence identity, with Pakistani isolates clustering with those from Saudi Arabia, Iran, and India. In total, 13 global haplotypes were identified, with Hap_3 dominating (53%) and shared across regions. Within Pakistan, eight haplotypes were detected, including region-specific variants, yielding high overall diversity (Hd 0.69; π = 0.007). District-level analysis showed that DI Khan and Bakkar had the highest haplotype diversity (Hd 0.73 and 0.71) but low nucleotide diversity ( π = 0.005–0.006), whereas Kohat exhibited no haplotype diversity. Population structure was higher in Pakistan (FST 0.26; Nm 0.7) than globally (FST 0.17; Nm 1.19), consistent with low gene flow among Pakistani populations. No natural Wolbachia infections were detected in Ae. aegypti . Conclusions: Aedes aegypti in Pakistan belong to a globally monophyletic lineage and show moderate mitochondrial diversity with higher population structure than the global population. The lack of detected Wolbachia infections suggests that natural strains are either absent or occur at very low prevalence. These findings provide a baseline for surveillance and support integrating Wolbachia -based biocontrol alongside conventional interventions in Pakistan. Graphical

BACKGROUND: The sterile insect technique (SIT) is a green and species‐specific insect pest control technique that suppresses target populations by releasing factory‐reared, radiosterilized males into the wild. Once released, it is important to be able to distinguish the released males from the wild males for monitoring purposes. Several methods to mark the sterile males exist. However, most have limitations due to monetary, process efficiency, or insect quality. Aedes albopictus is naturally infected with Wolbachia at a high prevalence, therefore the elimination of Wolbachia can serve as a biomarker to distinguish factory‐reared male mosquitoes from wild conspecifics.RESULTS: In this study, a Wolbachia‐free Ae. albopictus GT strain was developed and its fitness evaluated, which was found to be comparable to the wild GUA strain. In addition, GT male mosquitoes were irradiated at the adult stage and a dose of 20 Gy or more induced over 99% sterility. Moreover, a dose of 30 Gy (almost completely sterilizing male and female mosquitoes) had limited effects on the mating competitiveness of GT males and the vector competence of GT females, respectively. However, radiation reduced mosquito longevity, regardless of sex.CONCLUSION: Our results indicate that the Ae. albopictus GT strain can be distinguished from wild mosquitoes based on Wolbachia status and shows similar fitness, radio‐sensitivity and arbovirus susceptibility to the GUA strain, indicating that it is feasible to use the GT strain to suppress Ae. albopictus populations for SIT programmes. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The geographic boundaries of arboviruses continue to expand, posing a major health threat to millions of people around the world. This expansion is related to the availability of effective vectors and suitable habitats. Armigeres subalbatus (Coquillett, 1898), a common and neglected species, is of increasing interest given its potential vector capacity for Zika virus. However, potential distribution patterns and the underlying driving factors of Ar. subalbatus remain unknown. In the current study, detailed maps of their potential distributions were developed under both the current as well as future climate change scenarios (SSP126 and SSP585) based on CMIP6 data, employing the MaxEnt model. The results showed that the distribution of the Ar. subalbatus was mainly affected by temperature. Mean diurnal range was the strongest predictor in shaping the distribution of Ar. subalbatus, with an 85.2% contribution rate. By the 2050s and 2070s, Ar. subalbatus will have a broader potential distribution across China. There are two suitable expansion types under climate change in the 2050s and 2070s. The first type is continuous distribution expansion, and the second type is sporadic distribution expansion. Our comprehensive analysis of Ar. subalbatus’s suitable distribution areas shifts under climate change and provides useful and insightful information for developing management strategies for future arboviruses.