Laboratory evaluation of the possibility of using the eggs of the chestnut moth Cameraria ohridella Deschka & Dimic, 1986 (Lepidoptera: Gracillariidae) to feed the trichogram

Abstract

Goal. Evaluation of the suitability and eggs of chestnut moth Cameraria ohridella for parasitism and development of trichogramma. Methods. Laboratory cultures of Trichogramma pintoi Voeg were used for research. and Trichogramma evanescens Westw., which were bred on the eggs of Sitotroga cerealella Oliv. The experiment was performed according to the following scheme: female trichogramma after mating was placed in a test tube in 5 replicates for each species. The tube was closed with a stopper and the sex of individuals under binoculars was checked. In test tubes with trichogram laid strips of paper with one-day eggs of chestnut moth (25 copies.). In 5 replicates and kept in a thermostat (temperature — 24—25°C; relative humidity — 65—67%). The percentage of trichogram revival and the ratio of males to females, life expectancy and fertility of females were determined. Trichogramma individuals, which were fed with grain moth eggs, served as controls. The experiment lasted until the complete death of the trichogram. The obtained results were processed statistically according to standard methods. Results. A small number of chestnut moth eggs pierced by trichogramma were detected, but embryonic development of the parasite’s eggs was not observed. Comparing the size of the eggs of the chestnut moth with the size of the eggs of the main squamous pests against which different species of trichogramma are effectively used, we can conclude that for the successful development of eggs T. pintoi and T. evanescens chestnut moth eggs are not suitable as feeders. Probably, in terms of size and biological quality, they do not correspond to the parameters of the ecological niche of the hosts of the family Trichogrammatidae. Conclusions. In the laboratory, it was found that the eggs of the chestnut moth are not suitable for parasitizing the trichogramma of T. pintoi and T. evanescens. The main pests of crops, which are effectively parasitized by different species of trichogramma, have an egg size in the range of 0.4—1.0 mm, while the size of chestnut moth eggs does not exceed 0.27—0.32 mm. It is possible that the size and biological quality of chestnut moth eggs do not meet the parameters of the ecological niche of entomophagous feeders of the family Trichogrammatidae. Further researches with use of various types of a trichogramma, first of all — T. dendrolimi Mats appear actual.