Fertility and timing of the embryonic development of Cameraria ohridella Deschka & Dimic, 1986 (Lepidoptera: Gracillariidae) in laboratory conditions at different temperatures

Abstract

Goal. The effect of temperature on fertility and the timing of the embryonic development of the chestnut moth under laboratory conditions was studied.
 Methods. Laboratory. Selected pupae of the chestnut moth were placed in thermostats (at a temperature of 15, 20, 25, 30). Then, 5 pairs of pupae of different sexes were placed in glass cages in which the paper was pre-inserted, as a substrate for egg laying. Experiments were performed in four versions — 10 replications each. Cages with each variant were placed in polythermostats at temperatures of 15, 20, 25 and 30°С. After the butterflies flew out, the paper was taken out of the cage regularly (every two days) and under a microscope of MBS-9 (eyepiece 0.6 magnification 2), the number of laid eggs and caterpillars that hatch were counted. The results were processed statistically by standard methods for biological data.
 Results. It was determined that at a temperature of 15°C 50% of caterpillars were released from 40 eggs. At 25°C, out of 187 laid chestnut moth eggs, 65% of caterpillars were released. At 20°C, butterflies laid aside 83 instances. 54% of the caterpillars were released. At 30°C, the female chestnut moth was set aside on 17 instances eggs whose embryonic development has not occurred. It was revealed that at 15 and 30°С females are the least active, thus, optimal temperatures for keeping the chestnut moth in laboratory conditions are in the range of 20—25°С. Under these conditions, butterflies mate and lay eggs, the survival rate of which reaches 54—65%. The technique makes it possible in the laboratory to investigate the influence of environmental factors on the state of the chestnut moth population.
 Findings. It was determined that in laboratory conditions the optimum temperature for the deposition of chestnut moth eggs is 25°C. Butterflies favor the green substrate. Embryonic development lasts 6.1 ± 0.12 days, the survival rate of the populations is 25%. The method of obtaining chestnut moth eggs allows for in-depth experimental studies of the influence of environmental factors on the state of the chestnut moth population.