SMOKE AND TARGET COLOR EFFECTS ON DEFENSIVE BEHAVIOR IN YELLOWJACKET WASPS AND BUMBLE BEES (HYMENOPTERA, VESPIDAE, APIDAE) WITH A DESCRIPTION OF AN ELECTRONIC ATTACK MONITOR

The defensive behavior of colonies of Vespula pensylvanica (Saussure) and Bombus sonorus Say is assayed with an easily-constructed electroni c monitor that counts the number of impacts of insects attacking Ping- Pong ball targets. Black targets are attacked, and white targets are n ot. The administration of smoke to colonies before disturbing them gre atly reduces the number of attacks. In B. sonorus, the reduction was > 2-fold and in V. pensylvanica >10-fold. This suggests mechanisms of th e effect of smoke besides those that have been described for honey bee s. This effect may be useful to subdue these insects during insecticid e treatments to destroy their nests.