REPELLENCY OF WHEAT GERM EXTRACTS PREPARED WITH PEROXIDE-CONTAINING ETHER TO ADULTS OF TRIBOLIUM CONFUSUM (COLEOPTERA: TENEBRIONIDAE)

The fat soluble components of raw wheat germ were extracted with diethyl ether, and the extracts assayed for aggregant or arrestant activity with adults of the confused flour beetle, Tribolium confusum. Some extracts elicited a strong response, others had little effect, and still others were repellent. The concentration of peroxide in the ether was shown to be inversely correlated with the aggregating response evoked by the extract. In the preparation of extracts of biological material, therefore, solvents other than ether should be used unless the peroxide component is completely eliminated immediately before use.