Entomophages

Discover the Benefits of the Trichogramma Species We Cultivate

Trichogramma (Trichogramma spp.) are beneficial insects – extremely small parasitic wasps, ranging from 0.3 to 0.7 mm in size. They are widely used in biological plant protection around the world. Their role, both in nature and through human intervention, is due to their ability to parasitize the eggs of harmful insects, thus destroying them.

The control of several economically important pests, such as the European corn borer (Ostrinia nubilalis), cotton bollworm (Helicoverpa armigera), cabbage moth (Mamestra brassicae), and the grapevine moth (Lobesia botrana), has been proven to be successful and sustainable through the seasonal colonization method with Trichogramma.

Trichogramma belong to the family Trichogrammatidae, and the species from the genus Trichogramma are the most widely used in biological pest control. These miniature wasps (0.3 to 0.7 mm) parasitize the eggs of harmful insects, mainly moths and butterflies. The female Trichogramma lays her eggs in the eggs of the pest. The larvae of the Trichogramma, hatching from these eggs, consume their contents, leading to the death of the pest.

The technique for managing pest insects is part of Integrated Pest Management (IPM) and is particularly valued for its ecological sustainability – it does not harm non-target species and is safe for humans, plants, animals, beneficial insects, as well as for water and soil in the treated areas.

The ability of Trichogramma to reproduce in large quantities and its effectiveness against different types of pests make it a key element in modern organic farming and pest control solutions. This natural method has been widely studied and applied both in agriculture and forest ecosystems, providing long-lasting and environmentally friendly pest management solutions.

Trichogramma in Bulgaria

In Bulgaria, over 17 species of Trichogramma have been identified, which can develop up to 14 generations per year under local conditions. These wasps overwinter as pre-pupae in the eggs of their hosts, including moths, leafrollers, geometrid moths (Geometridae), white butterflies (Pieridae), and others, which parasitize weeds and plant debris.

The life cycle of Trichogramma, similar to that of many polyphagous entomophages, is not synchronized with that of its hosts. This is one of the reasons for their mass cultivation in biological laboratories and their application through the seasonal colonization method. Continuous development throughout the growing season, facilitated by the transition between different hosts, allows Trichogramma to maintain high numbers and effectively regulate pests.

Mode of action

The female wasps find the eggs of the hosts by using specific kairomones (chemical substances emitted by the hosts), after which they “inspect” the eggs with their antennae before laying their eggs in them. Typically, only one egg of the parasite is laid in the host’s egg, but larger eggs may accommodate multiple parasitic eggs. When the female Trichogramma lays her egg, she injects a secretion that interrupts the development of the host’s embryo, destroying its organs and systems. Externally, parasitized eggs darken to a gray-black or black color.

The female wasps also kill some of the host’s eggs by piercing them with their ovipositor and feeding on their contents.

Golden-eye (Chrysoperla carnea)

Chrysoperla carnea is one of the most effective biological agents for controlling pests such as aphids, young moth larvae, beetles, and mites. Their polyphagous nature makes them valuable in agricultural ecosystems.

You can read more about the individual Trichogramma species we cultivate by clicking on the links above.