Localized Control of Aedes aegypti (Diptera: Culicidae) in Miami, FL, via Inundative Releases of Wolbachia-Infected Male Mosquitoes

Abstract

As part of the response to autochthonous Zika transmission in the United States, the City of South Miami implemented a 6-mo period in which Wolbachia-infected WB1 Aedes aegypti (L.) males were released into an ~170-acre area. Intracellular Wolbachia bacteria infections in Ae. aegypti cause early embryonic arrest (known as cytoplasmic incompatibility [CI]) and egg hatch failure, and inundative introductions have been suggested as a potential control tool. Throughout the release period, the Ae. aegypti population was monitored within both the release area and an equivalent area that did not receive WB1 male releases. The results show a significant reduction in egg hatch at the area receiving WB1 males, which is consistent with expectations for CI. Similarly, the number of Ae. aegypti was significantly reduced at the area receiving WB1 males, relative to the untreated area. The observed population reduction and results encourage additional work and replication of the Wolbachia biopesticide approach against Ae. aegypti, as an additional tool to be integrated with existing control tools for the control of this medically important vector and nuisance pest.

A bacterium against the tiger: preliminary evidence of fertility reduction after release of Aedes albopictus males with manipulated Wolbachia infection in an Italian urban area

“…albopictus . This trait strongly reduces costs and constraints associated with the need to have a 100% sexing separation efficiency, or to combine IIT with irradiation, as is required in the case of IIT based on uni‐directional cytoplasmic incompatibility . Reduced vector competence of Ae.…”

“…24 This trait strongly reduces costs and constraints associated with the need to have a 100% sexing separation efficiency, or to combine IIT with irradiation, as is required in the case of IIT based on uni-directional cytoplasmic incompatibility. 27,46,50 Reduced vector competence of Ae. albopictus incompatible lines 51 would make the accidental release of few female even more tolerable, although this is not compulsory in temperate non-endemic regions.…”

“…full embryogenic lethality in the progeny of females either uninfected or harbouring a Wolbachia strain non‐compatible with that of its mate . Because Wolbachia is maternally inherited, and thus not transmitted by males, release of adequate numbers of males harbouring a Wolbachia strain incompatible with that of the wild females has the potential to eventually suppress the wild target population . In a pilot study carried out in Kentucky (USA), release of w Pip‐infected males in the field induced a localized reduction in both egg hatch and adult female numbers in the local Ae.…”

Persistent deleterious effects of an unstable deleteriousWolbachiainfection

“…This approach to suppression does not require sex separation unlike strategies that rely on cytoplasmic incompatibility (Mains et al 2019) and could be effective even if the infection does not persist in the long-term. Although research has shifted away from this deleterious Wolbachia infection, wMelPop may still prove to be useful when seasonal population suppression is desirable.…”

Does membrane feeding compromise the quality ofAedes aegyptimosquitoes?

“…Some programs involve male-only releases that aim to suppress populations. Males that are irradiated [2], genetically modified [3] or infected with Wolbachia [4] can be released into the field and mate with wild females, reducing their fertility. Other programs involve releases of both males and females which aim to replace natural populations with mosquitoes that have a reduced capacity to transmit diseases.…”