Post-fumigation productivity of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) exposed to acrylonitrile, adjuvants of acrylonitrile, acrylonitrilel-adjuvant mixtures and other modern fumigants

Abstract

LD50 doses of chloropicrin, ethylene oxide, ethylene dibromide, acrylonitrile plus 8% carbon dioxide, and acrylonitrile plus ethylene dibromide were found to decrease the productivity of adults of Sitophilus oryzae (L.) and Tribolium castaneum (Hbst.). Acrylonitrile, acrylonitrile plus methyl iodide and phosphine caused a reduction in productivity in 5. oryzae but not in T. castaneum. Carbon dioxide decreased the productivity of T. castaneum. Carbon tetrachloride, methylene chloride, methyl bromide, methyl iodide, acrylonitrile plus carbon tetrachloride and acrylonitrile plus methylene chloride had little influence on the productivity. The productivity of T. castaneum exposed to trichloroethylene and acrylonitrile plus trichloroethylene was higher than in control batches.

Post-fumigation productivity ofTrogoderma granariumEverts (Coleoptera: Dermestidae)

“…A study on the productivity of the survivors following fumigation is useful in addition to mortality data. The effect of fumigants on the productivity of Callosobruchus chinensis (L.), Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) was reported earlier (Rajendran & Muthu, 1981).…”

“…Loschiavo (1960) noted reduced fecundity of T. confusum DuVal exposed to ethylene dibromide. The productivity of adults of T. castaneum and S. oryzae was decreased after fumigation with ethylene dibromide at the LD50 (Rajendran & Muthu, 1981). These authors also noted that whereas exposure to methyl iodide and carbon tetrachloride, either alone or mixed with acrylonitrile, had little effect on the productivity, exposure to trichloroethylene increased the numbers of progeny.…”

“…However, the fertility of adults of Ephestia elutella (Hiibner) developing from diapausing larvae fumigated with methyl bromide was depressed (Bell, 1977). Rajendran & Muthu (1981) found that a dose of ethylene oxide achieving 50% kill markedly inhibited the productivity of adults of Tribolium castaneum and S. oryzae, but similar exposure to methyl bromide did not. They also found that carbon dioxide (50%) producing 32% mortality, affected the reproduction potential of T. castaneum.…”

“…Punj (1970) noted that methyl bromide was more toxic than ethylene dibromide to the full grown (age not given) larvae based on mortality counts on the seventh day following fumigation. However, for ethylene dibromide, a period of at least 20 days is necessary for end-point mortality (Rajendran & Muthu, 1981).…”

“…Based on trial experiments, five doses were selected for productivity studies for each fumigant and six replicates were carried out for each dose. The larvae were fumigated in 0-85-litre desiccators for 24 h at 26-30°C and 60-75% RH as described by Rajendran & Muthu (1981).…”