ISHS Acta Horticulturae 462: I Balkan Symposium On Vegetables and Potatoes
OVICIDAL EFFECT ON INSECTICIDES USED IN CONTROL OF LEPTINOTARSA DECEMLINEATA SAY |
| Authors: | D. Inðjic, Z. Klokocar-Šmit, B. Orbovic, I. Peric, M. Šestovic |
| Keywords: | cypermethrin, fenvalerate, carbosulfan, chlorpyriphos, phosmet, bensultap, methidathion, and thiocyclam |
| DOI: | 10.17660/ActaHortic.1997.462.58 |
| Abstract:
Most often, the effect of insecticides is presented as the effect of these compounds on larval stage, the most harmful stage in Leptinotarsa decemlineata's life cycle. There are numerous data about the reaction on larvae and adults, but those on ovicidal action are the least available data. This stage is regularly exposed to the same field treatment as the other stages, and taking into account the high ratio of hatching, it was of interest to examine the insecticide effect. The first generation of eggs, collected form field, were exposed to the insecticides (cypermethrin, fenvalerate, carbosulfan, chlorpyriphos, phosmet, methidathion, besultap and thiocyclam) and their mixtures both at the beginning and at the end of the embryogenesis (48 and 96 h old). The ovicidal effect was determined as the percentage of unhatched larvae after the treatment with insecticides in field concentrations. The insecticide toxicity parameters were determined (LC50) as well as the homogeneity coefficient. The synergistic relation of binary mixtures was determined. The effect of 70 % unhatched larvae were obtained with thicyclame, cypermethrin, fenvalerate, carbosulfan. Bensultap, although it is chemically similar to thyocyclam, had the lowest ovicidal effect. The highest difference in toxicity -four times higher in later treatment- was attained with cypermethrin. The mixture with thiocyclam had the highest ovicidal effect in both of embryogenenetic phases. | |
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