Investigation of influence of calibration of grain moth eggs on production of trichogramma for biological protection of plants

Abstract

Improving the production of the biological preparation Trichogramma is an urgent task, as the quality indicators of the preparation Trichogramma determine its ability to provide effective biological protection of plants. The influence of the process of calibration of grain moth eggs on the production of Trichogramma was determined. This made it possible to recommend the developed grain moth eggs calibrator for use in the Trichogramma preparation process. With using of selected large grain moth eggs, Trichogramma evanescens Westw. was reproduced for six generations. The grain moth eggs, which were only cleaned, were used as controls. Also studies are conducted of the reproduction of Trichogramma pintoi Voeg., using selected large grain moth eggs for seven generations. The small grain moth eggs, which were obtained during pneumatic calibration, were used as controls. By the relationship between the grain moth eggs size and the Trichogramma рintoi Voeg. and Trichogramma evanescens Westw., the level of parasitized eggs was established. Studies have shown that Trichogramma рintoi Voeg. with using of selected large grain moth eggs from the third to the seventh generation had a level of parasitized eggs, which ranged from 76 to 90%. When the small grain moth eggs were used, the level of parasitized eggs sharply decreased from the third to the ninth generation. Trichogramma evanescens Westw., which bred on large grain moth eggs from the second to the seventh generation, had parasitized eggs, ranging from 83 to 93%. When cultivating Trichogramma evanescens Westw. on grain moth eggs that have been cleaned only without calibration, the high level of parasitized eggs in the range of 78 to 80% was only from the second to fourth generation. Since the fifth generation, Trichogramma evanescens Westw. level of parasitized eggs of the grain moth have been reduced and it led to a decreasing efficiency of the biological preparation Trichogramma.