Multiplication and application of the entomophagic Trichogramma in the control of the pest complex
Year: 2025
Type: conference-paper
Abstract: In the Republic of Moldova, the areas cultivated with agricultural crops are vast. Annual and perennial crops are attacked by various pest species, but the most economically important belong to the complex of cutworms, moths, and whiteflies. Most of these species are polyphagous, attacking over 120 species of cultivated and spontaneous plants, causing significant damage. Annually, crop losses range from 15–80%. The flight of butterflies from the overwintering generation begins when the sum of temperatures reaches 260–270°C and continues throughout the summer (2–3 generations). The widespread use of the entomophagous Trichogramma spp. in plant protection is linked to its quality in mass rearing and field application. It is reared on the laboratory host, the grain moth (Sitotroga cerealella Ol.). For the multiplication of Trichogramma sp., the host S. cerealella is reared. The technology of rearing S. cerealella includes several operations: preparation of barley – thermally processed at 95°C; then allowed to dry (2–3 days), after which it is infested with larvae of the grain moth (S. cerealella Ol.), applying one gram of moth eggs per kg of barley; the barley is mixed and moistened after 3–4 days; for host rearing, optimal conditions are 25–27 °C and 80–85% relative humidity; butterflies are collected daily; butterflies are placed in a collector and eggs are collected daily, which are used for Trichogramma rearing. The grain moth eggs are glued with water to the inner surface of glass containers (3-liter jars, glass cylinders, vivarium’s), then the parasite:host ratio is set to 1:20, meaning one Trichogramma female is given 20–30 moth eggs to parasitize; after 9 days, Trichogramma individuals hatch from the parasitized eggs. Before starting experiments with this entomophage, biological indices are determined. For example, biological indices of T. evanescens (collected from sweet corn crops) were: female prolificacy ranged from 20.4–24.0 eggs per female, emergence rate of individuals 82.0–86.0%, female ratio 52.7–56.0%, static quality criterion 8.9–11.5, parasitism rate 80.0–84.0%, female progeny-bearing rate 80.0–84.0%, and female lifespan 2.2–2.9 days. Before field release, pheromone traps are installed to monitor pests, and depending on pest density, Trichogramma is released. The effectiveness of field releases depends on the rearing procedures, specific species, and biotic and abiotic factors. Controlling pest insect species densities in modern concepts of biological plant protection is one of the key links in trophic chains and networks, ensuring high environmental quality, enabling the production of ecological agro-food products, reducing or eliminating chemical treatments, and preserving beneficial fauna.
Author: Lidia Gavrilita
Institution: Moldova State University
Language: English
Subfield: Insect Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: bronze
OpenAlex ID: W7204709853