Silver — Y moth Autographa gamma L.

Ubiquitous in Bulgaria. Damages many crops: black currant, apple, pear, ornamentals, sunflower, corn, vegetables, potatoes.

They overwinter as caterpillars, pupae and butterflies. The flight is from April to November. The average fecundity of 1 female is between 500–1500 eggs. Important — eggs laid are scattered 1–2–3–6 eggs on the underside of the leaves. This makes it difficult for the trichogramma to detect them. Caterpillars feed on more than 90 species of plants. In Bulgaria there are 3 generations per year. The threshold of economic harm is 10 caterpillars/m2.

To obtain acceptable efficiency from the use of the trichogramma, both the rate and the number of displacements must be increased.

Displacement is as for alfalfa nightshade, subject to monitoring results with pheromone traps.  In the case of mass distribution and high density, it is necessary to make 3 displacements in areas where the HCT is = 0.9–1.2. In other areas — additional displacements or increased rate.