ORAL TOXICITY OF BORIC-ACID AND OTHER BORON-COMPOUNDS TO IMMATURE CATFLEAS (SIPHONAPTERA, PULICIDAE)

Oral toxicity was characterized in first-instar cat fleas, Ctenocephal ides felis felis (Bouche), feeding on dried blood treated with boric a cid. LC(50) values ranged from 2.11% after 24 h to 0.21% after 7 d. In carpet tests with five different boron compounds and a number of diff erent formulations, significant mortality for first instars was observ ed in all cases. In similar tests with prepupae and cocoons, there was no significant effect on mortality. The importance of these results i s discussed in light of current application procedures for boron compo unds, and suggestions are made for future research.