P 6 - Establishment and stability of Wolbachia (wAlbB strain) in Aedes aegypti populations from the Yucatan Peninsula, México

Aedes-borne diseases (ABDs) such as dengue, Zika and chikungunya pose an enormous burden to the public health systems worldwide. As no effective vaccines or therapy are available, vector control programs remain as one of the main strategies to defeat these diseases. In Mexico, the Ministry of Health is interested in incorporating the incompatible insect technique (IIT) using Wolbachia-induced cytoplasmic incompatibility to suppress the populations of Aedes aegypti and reduce the incidence of ABDs. In the Laboratory for Biological Control of Aedes aegypti of the University of Yucatan (LCB-UADY) - a reference insectarium for national and local vector programs - we are establishing and mass-rearing local Wolbachia-free and Wolbachia-infected Ae. aegypti lines from two different areas of Mexico, Quintana Roo (QROO) and Campeche (CAMP) states. Briefly, emerging females (F₀) from ovitrap-collected eggs were maintained for oviposition, offsprings were reared under laboratory conditions for two generations (F₂), and then screened for Wolbachia infection by qPCR (Zhang et al. 1998; Puerta-Guardo et al. 2020). Wolbachia-free males (wild-type ♂ receptor line (F₂), n=30) from both states were selected for outcross breeding with females carrying Wolbachia wAlbB strain (wMID♀ donor line (F₃₅), n=30) (Liang et al., 2022) from the Yucatan state. After three crossing generations (G₃), two new Ae. aegypti lines carrying Wolbachia (wAlbB) from Campeche and Quintana Roo, hereafter designated as wCAMP and wQROO, were successfully established (100%) as confirmed by qPCR. Further analyses to evaluate life-history traits such as fecundity, fertility, longevity, cytoplasmic incompatibility, and male mating competitiveness as well as Wolbachia infection through sequential generations of the two new Wolbachia infected lines, wCAMP and wQRO, were performed to compare to the wild type populations. These results provide significant insights regarding the future implementation of Wolbachia-based strategies for vector control not only at local but national levels.