Aerial Application of Bacillus thuringiensis (Dipel) against Colotois (Himera) pennaria L. in Comparison with ULV-Application of Various Insecticides 1)

In spring 1972 experiments were carried out in Lower Austria with the Bacillus thuringiensis isolate Dipel in order to assess its effectiveness in controlling Colotois pennaria L. infesting oak and other broad-leaved trees. The results obtained compared favourably with those produced by the insecticides Nexion²), malathion and Dipterex³), although both malathion and Dipterex yielded higher mortality. Similar results were obtained when B. thuringiensis was used to control Stilpnotia salicis L., feeding on poplar trees. Neodiprion sertifer Geoffr. and Pris-tiphora abietina Christ., however, were not affected.