Candidate Aerosol and Dust Formulations for Disinfesting Transport Vehicles, 1984

Abstract

Abstract Laboratory-reared stored-product insects were exposed to insecticidal formulations in transport trailers (ca. 32 m3 or 71 m3) at Baltimore, MD and Miami, FL. For each test, 40 insects of each species were held in 10-cm diam open petri dishes placed on the floor at the midsection of each trailer ca. 30 cm from a side wall. Each trailer was used only once. The aerosols were propelled by Freon 11/12 and released within closed trailers by an individual walking the length of the trailer and releasing the aerosol from the pressurized can for the required amount of time. Dusts were formulated with HiSil 233 (except for a wettable powder formulation of permethrin) as a carrier and introduced into the trailer by CO2 propellant through an open rear door. The exposure period was 5 h; 10 min in the closed trailer after each aerosol or dust application, 20 min with one door of the trailer opened for aeration, and 4.5 h in the original containers after their removal from the trailers and before the insects (treated and untreated) were transferred to clean petri dishes. Insects were observed after 24 h for knockdown (KD) (those that could not walk or remain in an upright position). The insects were held in petri dishes without food for 14 days at 27°C ± 1°C and 60% RH, and then examined for mortality, expressed as dead plus moribund (D + M) insects (those that showed little or no movement when lightly stimulated with a small camel-hair brush). Each test was replicated on 3 successive days. Control in untreated trailers were also replicated on 3 successive days. The average air temperature inside the trailers at treatment was 28 ± 6°C.