219 Abstract: Toxicity of neem extract in comparison with DDVP (Dichlorvos) was determined against the housefly (Musca domestica L). Neem leaf extract was applied at 5, 10, 20, 40 and 80 microgram/fly and DDVP was treated in 0.1, 0.2, 0.4, 0.8 and 1.6 microgram/fly doses. Lethal dose values were calculated with probit analysis and LD50 and LD90 values were found to be 8.4 and 169.8 ug/fly of ne...

A new blocked mutant of Aspergillus parasiticus produces no detectable aflatoxin B1, but accumulates several polyhydroxyanthraquinones. One of these pigments was identified as averantin. This is the first report of its formation by A. parasiticus. Radiotracer studies with [14C]averantin showed that 15.3% of label from averantin was incorporated into aflatoxin B1. This incorporation was blocked ...

Ethyl formate applied as an aerosol killed almost 100% of the mould mites (Tyrophagus putrescentiae) present in tissue culture tubs. Mite mortality showed dose responses to the chemical and mortality increased with duration of exposure. Other aerosol formulations, and vacuum and controlled atmosphere treatments were also tested but were not effective in controlling mites. Onion thrips (Thrips t...