Assessment of a Novel Adult Mass-Rearing Cage for Aedes albopictus (Skuse) and Anopheles arabiensis (Patton)

Abstract

Simple Summary

Aedes albopictus (Asian tiger mosquito) and Anopheles arabiensis mosquito species can transmit several pathogens, including viruses and parasites which are the causative agents of diseases such as dengue, chikungunya, yellow fever, Zika and malaria, respectively. The use of insecticides against mosquito vectors has shown its limits. Proper management of these mosquito vectors is critical to prevent and/or control dengue outbreaks and malaria. Therefore, complementary vector control methods such as the sterile insect technique are envisioned. The potential to suppress mosquito populations by applying the sterile insect technique has been demonstrated in several countries. However, the technique, which relies on the mass-production of sterile males, needs innovations in mosquito mass-rearing techniques, including the development of low-cost adult cages. Here, we assessed the suitability of a new adult cage for mass egg production and egg quality for Aedes albopictus or Anopheles arabiensis mosquito species. Our results show the potential of the new cage for a mass production of high-quality eggs required for a sterile insect technique program targeting these mosquito species. Although the new cage has shown several advantages, further improvements are necessary to achieve economic efficiency and high production rates.

Abstract

Successful implementation of the sterile insect technique (SIT) against Aedes albopictus and Anopheles arabiensis relies on a continuous supply of sterile males. To meet this requirement, optimization of the mass-rearing techniques is needed. This study, therefore, aims to assess a new mass-rearing cage (MRC) in terms of egg production efficiency and egg hatch rate (quality). In addition, adult survival was evaluated based on a cage adult-index for Ae. albopictus. Moreover, the cage’s suitability for use in mass An. arabiensis egg production was compared to that of the FAO/IAEA Anopheles reference cage. In Ae. albopictus rearing, the new MRC produced 1,112,110 eggs per cage following six blood meals, with minimum loss of eggs in the egging water. Furthermore, the adult index gave a good proxy of daily mortality rates in Ae. albopictus. In An. arabiensis rearing, about 130,000 eggs per egg batch were collected both from the new and the reference MRC. These findings suggest that the new MRC prototype is efficient in terms of egg production and can be used for mass-rearing in SIT programs targeting Ae. albopictus as well as An. arabiensis. The adult index was also positively validated for the detection of unusual mortality rates in Ae. albopictus mass-rearing facilities. Overall, the new MRC has shown several advantages; however, further improvements are necessary to minimize escapes during the egg collection processes.