An autodissemination station for the transfer of an insect growth regulator to mosquito oviposition sites

Abstract

A prototype autodissemination station to topically contaminate oviposition-seeking container-dwelling mosquitoes with the insect growth regulator, pyriproxyfen, was developed and tested in the laboratory. Our test subject was the Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae), an urban species that colonizes small-volume cryptic larval habitats and is a skip ovipositor that visits multiple containers. The station consists of a water reservoir to attract gravid females, which is joined to a transfer chamber designed to contaminate visiting mosquitoes. The unit is easily constructed by moulding wet shredded cardboard using corn starch as a binder. The essential criteria that must be met to prove the efficacy of an autodissemination station require it to demonstrate effectiveness in attracting the target insect, in transferring the toxicant to the insect that will disperse the agent, and in facilitating the subsequent transfer of the toxicant from the insect to target habitats at a lethal concentration. Cage experiments demonstrated that the unit was readily accepted by gravid females as an oviposition site. A powder formulation of pyriproxyfen-impregnated silica particles adhered to visiting Ae. albopictus females (mean: 66 particles/female), although particles were lost over time. In cage (2.2 m(3) ) trials, pyriproxyfen-charged stations resulted in 100% inhibition of adult emergence, whereas in small-room (31.1 m(3) ) trials, 81% emergence inhibition was recorded. The venereal transfer of pyriproxyfen from contaminated males to virgin females was also observed, and pyriproxyfen was subsequently transferred to water-holding containers at concentrations that inhibited emergence. Key autodissemination station features include lack of maintenance requirements, biodegradable construction, low cost and low risk.

Male mosquitoes as vehicles for insecticide

“…An obvious opportunity for horizontal transfer between males and females is via coupling during mating and mating attempts. This type of transfer would be similar to that described in previous work with auto-dissemination stations [18]. Indirect transfer to females, via resting surfaces, e.g., water or ovisite sides (Fig.…”

“…Auto-dissemination approaches are being explored for mosquitoes [18,19]. Proposed autodissemination methods are based on the behavior of adult mosquitoes and their attraction to breeding sites, including cryptic sites that human operators may often fail to find.…”

Residual Treatment ofAedes aegypti(Diptera: Culicidae) in Containers Using Pyriproxyfen Slow-Release Granules (Sumilarv 0.5G)

“…However, the auto-dissemination of pyriproxyfen, either as a dust or dissolved in water, could be used to treat cryptic and inaccessible breeding sites such as septic tanks and roof gutters. Contaminated mosquitoes could be used to transfer effective doses of pyriproxyfen to such sites (Devine et al 2009, Caputo et al 2012, Gaugler et al 2012. Devine et al (2009) demonstrated that adult Ae.…”

Development and Evaluation of an Attractive Self-Marking Ovitrap to Measure Dispersal and Determine Skip Oviposition inAedes albopictus(Diptera: Culicidae) Field Populations

“…Devices have been developed to contaminate a skip ovipositing mosquito with an IGR such that the mosquito will transfer the chemical to other ovisites (Caputo et al 2012, Gaugler et al 2012. To maximize effectiveness, the placement of IGR-treated ovisites in the environment should take into account Ae.…”

“…This knowledge is critical to development of new approaches in Ae. albopictus control where skip ovipositing mosquitoes might be used to distribute an insect growth regulator (IGR) to multiple larval habitats (Caputo et al 2012, Gaugler et al 2012). The distance traveled by contaminated mosquitoes during skip oviposition will determine the extent to which such a control measure can be dispersed utilizing auto-dissemination techniques.…”