Evaluating Liquid and Granular Bacillus thuringiensis var. israelensis Broadcast Applications for Controlling Vectors of Dengue and Chikungunya Viruses in Artificial Containers and Tree Holes.
The principal vectors of chikungunya and dengue viruses typically oviposit in water-filled artificial and natural containers, including tree holes. Despite the risk these and similar tree hole-inhabiting mosquitoes present to global public health, surprisingly few studies have been conducted to determine an efficient method of applying larvicides specifically to tree holes. The Stihl SR 450, a backpack sprayer commonly utilized during military and civilian vector control operations, may be suitable for controlling larval tree-hole mosquitoes, as it is capable of delivering broadcast applications of granular and liquid dispersible formulations of Bacillus thuringiensis var. israelensis (Bti) to a large area relatively quickly. We compared the application effectiveness of two granular (AllPro Sustain MGB and VectoBac GR) and two liquid (Aquabac XT and VectoBac WDG) formulations of Bti in containers placed on bare ground, placed beneath vegetative cover, and hung 1.5 or 3 m above the ground to simulate tree holes. Aedes aegypti (L.) larval mortality and Bti droplet and granule density data (when appropriate) were recorded for each formulation. Overall, granular formulations of Bti resulted in higher mortality rates in the simulated tree-hole habitats, whereas applications of granular and liquid formulations resulted in similar levels of larval mortality in containers placed on the ground in the open and beneath vegetation.
Navy Entomology Center of Excellence, Box 43, Building 937, Naval Air Station, Jacksonville, FL 32212. james.f.harwood3.mil@mail.mil.
James F
JF
Harwood
Navy Entomology Center of Excellence, Box 43, Building 937, Naval Air Station, Jacksonville, FL 32212.
Muhammad
M
Farooq
Navy Entomology Center of Excellence, Box 43, Building 937, Naval Air Station, Jacksonville, FL 32212.
Brent T
BT
Turnwall
Navy Entomology Center of Excellence, Box 43, Building 937, Naval Air Station, Jacksonville, FL 32212.
Alec G
AG
Richardson
D000818:Animals; D001413:Bacillus thuringiensis / Q000737:chemistry*; D002646:Chikungunya virus; D009033:Culicidae / Q000187:drug effects* / Q000821:virology; D003716:Dengue Virus; D007303:Insect Vectors / Q000187:drug effects* / Q000821:virology; D007306:Insecticides / Q000494:pharmacology; D007814:Larva / Q000187:drug effects*; D009032:Mosquito Control / Q000379:methods*; D010572:Pest Control, Biological / Q000379:methods*; D014197:Trees
D007306:Insecticides
Aedes aegypti; Stihl SR 450; backpack sprayer; ground applications; larval mosquito control