Vacuum fumigation schedule for seed inhabiting chalcidoids

For developing a vacuum rumigation disinfestation schedule, the susceptibility studies of two indigenous seed inhabiting species, viz., Bruchophagus mellipes Gahan infesting seeds of Sesbania aculeata Poir, and Systole albipennis Walker infesting seeds of Coriandrum sativum Linn. and Foeniculum vulgare Linn., were conducted. Pupae in infested seeds required the highest concentration of carbon disulphide, methyl bromide and hydrogen cyanide gas. Further, fumigation with carbon disulphide @ 1230 mg/l or methyl bromide @ 64 mg/l or hydrogen cyanide gas @ 47.1 mg/l for 2 h at reduced pressure equivalent to 200 mm of mercury and at 27° ± 0.5°C, proved effective. These concentrations of fumigants did not show any emergence/survival of any insect in the larger samples containing larger population and also did not affect the germination of the fumigated seeds. This schedule has now become indispensable for treatment of seed samples infested with exotic species of chalcidoids under import.