積穀混拌藥劑貯存殘餘毒效持久性試驗

Residual Persistance on the Control of Stored Granary Insects with Insecticide Dust

林欉(Tsung Lin)

《中華農業研究》 9卷3期 (1960/09) Pp. 24-27

並列摘要

0.08% pyrethrins-1.2% piperonyl butoxide dust 1:500 and 0.2% lindane dust 1:500 were mixed in 20 kilograms of brown rice including check (untreated) kept in ordinary room temperature for use in this study. 200 grams of kept rice were taken out monthly and added 200 adults of alive rice weevil, Sitophilus oryzae Linne for residual test and then keeping in incubator around 29-30℃. After 72, 95 and 144 hours respectively all dead weevils were picked out and its mortality was counted as the indicator of the insecticide residual effects. The results were shown in tables 1-3 and figures 1-2.
According to these figures, the residual effect of pyrenone dust seemed to be much shorter than lindane dust, Its residual effect decreased 50% over and almost nil after 2 and 3 months keeping respectively. While lindane dust even being kept for 8 months the residual effect was still having 50% over and 10 months later the effect contrarily increased to 70%. This phenomenon is unable to be explained now and has to wait for additional study.
Observation on the stored rice mixed with pyrenone or lindane dust after 10 months storage, the mortality of pyrenone and lindane treatments were 51.6% and 94.2% respectively. Whenever, lindane treatment in 9 months storage, the occurred weevils were all dead but in pyrenone treatment there were all alive. Therefore the difference between these two insecticides showed that the effect of lindane had 5 more months longer than pyrenone did.