Abstract: | Summary The thrust out-reflex of the back beetles is useful to the breeding galleries of bore-meal and other substances. The beetles also avert with this reflex other insects, who try to invade the breeding galleries. Then the bark beetle thrust out its abdomen and often that means the ruin of the beetle. The enemy — f. i.Thanasimus formicarius L. — has the opportunity to kill the bark beetle when he reaches its abdomen. |