Area-Wide Ground Applications of Bacillus thuringiensis var. israelensis for the Control of Aedes albopictus in Residential Neighborhoods: From Optimization to Operation

Abstract

The increasing range of Aedes albopictus, the Asian tiger mosquito, in the USA and the threat of chikungunya and dengue outbreaks vectored by this species have necessitated novel approaches to control this peridomestic mosquito. Conventional methods such as adulticiding provide temporary relief, but fail to manage this pest on a sustained basis. We explored the use of cold aerosol foggers and misting machines for area-wide applications of Bacillus thuringiensis var. israelensis (VectoBac WDG) as a larvicide targeting Aedes albopictus. During 2010–2013 we performed initially open field trials and then 19 operational area-wide applications in urban and suburban residential areas in northeastern USA to test three truck-mounted sprayers at two application rates. Area-wide applications of WDG in open field conditions at 400 and 800 g/ha killed on average 87% of tested larvae. Once techniques were optimized in residential areas, applications with a Buffalo Turbine Mist Sprayer at a rate of 800 g/ha, the best combination, consistently provided over 90% mortality. Importantly, there was no significant decrease in efficacy with distance from the spray line even in blocks of row homes with trees and bushes in the backyards. Under laboratory conditions Bti deposition in bioassay cups during the operational trials resulted in over 6 weeks of residual control. Our results demonstrate that area-wide truck mounted applications of WDG can effectively suppress Ae. albopictus larvae and should be used in integrated mosquito management approaches to control this nuisance pest and disease vector.

Targeting a Hidden Enemy: Pyriproxyfen Autodissemination Strategy for the Control of the Container Mosquito Aedes albopictus in Cryptic Habitats

“…albopictus in larval habitats. Larvicides are applied with backpack or larger motorized sprayer such as a truck-mounted low and ultralow volume sprayers [9,10]. For instance, Bacillus thuringiensis var.…”

“…For instance, Bacillus thuringiensis var. israelensis is a well-established larvicide used for mosquito control, particularly in urban areas, with proven efficacy [8,10]. It is imperative for any larvicide application to reach concealed cryptic habitats, where this mosquito prefers to oviposit.…”

Reducing the Risk of Zika and other Arboviruses by Rapidly Eliminating Aedes albopictus Larvae from Tires Using a Spray Formulation of Bacillus thuringiensis israelensis.

“…Identifying both the area at risk and optimizing surveillance sites in probable hot zonesis essential for preventing invasion of Zika virus, reducing the impact of an outbreak, preventing recruitment of infected conspecificsfrom other geographic regions.Aerial and truck mounted application of adulticides for control of Ae albopictus and Ae aegyptican contribute to control but their short term effectiveness must be incorporated into the integrated mosquito management plan. For example, truck mounted spraying of Bti using a cold thermal-fogger was effective in penetrating into the surrounding habitat of bushes and reducing Ae albopictus larvae (Williams et al 2014). In addition to the frequency and cost of area-wide larvicide application, most operations use formulations intended for other uses andare only conducted with equipmentavailable on hand (Faraji and Unlu, 2016).…”

Truck‐mounted area‐wide applications of larvicides and adulticides for extended suppression of adult Aedes albopictus

“…As an alternative to source reduction, containers can be treated with a residual larvicide. To reduce the labor costs associated with larviciding campaigns, the use of truck‐mounted spray equipment to apply larvicides on an area‐wide basis has been examined . This has the added benefit of treating containers in residential properties to which mosquito control personnel have limited access .…”

“…Most studies have applied liquid formulations of Bacillus thuringiensis var . israelensis ( Bti ) de Barjac 1978 (Valent BioSciences Corp., Libertyville, IL, USA) using truck‐mounted ultra‐low volume (ULV) sprayers or mist blowers for the successful control of container‐inhabiting Aedes species . However, other pesticide formulations utilizing insect growth regulators such as pyriproxyfen and methoprene have also shown promise …”