The efficacy of the bioinsecticides NeemAzal T/C, Tracer 480 SC, Preferal WG and Dipel DF, allowed for application in organic farming in Bulgaria, against larvae and adults of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) was studied under laboratory conditions. The fastest initial effect showed Tracer 480 SC and on the first day after treatment efficacy of 80% for larvae and 60% for adults was reported. The efficacy reached 100% on the 3-rd and 7-th day after the treatment, respectively for larvae and adults. The action of the bioinsecticide NeemAzal T/S was delayed and the efficacy was reported on the 5-th day after treatment of 50% and 22.2%, respectively for the larvae and adults. The efficacy gradually increased and on 9-th day after treatment and reached 100% for larvae and only 33.3% for adults. The slowest action showed the Preferal WG and Dipel DF bioinsecticides. The efficacy of both preparations on the 9-th day after the treatment reached 75% for the larvae, and 100% by treatment with Preferal WG at a concentration of 0.2%. Lower efficiency of 55.56% for adults, compared with larvae on the 9-th day after treatment with Preferal WG and Dipel DF in all tested concentrations was observed.
Efficacy of bioinsecticides against the colorado potato beetle, Leptinotarsa Decemlineata (SAY) (Coleoptera: Chrysomelidae) under laboratory conditions