Trichogramma

Meet the Different Species of Trichogramma We Cultivate

Trichogramma are beneficial insects – very tiny wasps, measuring 0.3-0.7 mm, that have an exceptionally wide application in biological plant protection worldwide.

The role assigned to them by nature and humans is due to their ability to parasitize the eggs of harmful insects, thereby killing them.

The control of economically important pests such as the corn stem borer (Ostrinia nubilalis), cotton bollworm (Helicoverpa armigera), cabbage moth (Mamestra brassicae), grapevine moth (Lobesia botrana), and many others has been proven to be most successful and with the longest-lasting effects through the application of Trichogramma using the so-called seasonal colonization method.

Due to their valuable qualities and the possibility of mass reproduction, scientists from all over the world have been researching their species composition, biological and ecological characteristics, and practical applications for over a century.

How Does Trichogramma Works?

Trichogramma belong to the family Trichogrammatidae, but the species from the genus Trichogramma have the greatest practical significance.

In Bulgaria, more than 17 trichogramma species have been established, which under our conditions can develop up to 14 generations per year.
They survive the winter as pre-pupae in the eggs of their hosts – moths, leafrollers, loopers, white butterflies, etc., found on weed plants and plant residues.
The life cycle of Trichogramma (as well as other polyphagous entomophages) is not synchronized with that of their hosts, and this is one of the reasons for their mass breeding in biological laboratories and use by the seasonal colonization method. The continuous development of Trichogramma (the large number of generations) during the growing season is achieved through the switching of hosts, and their short life cycle allows them to develop in large numbers and carry out significant biological regulation.

Female wasps orient themselves in searching for their host’s eggs by the specific odors (kairomones) emitted by the host. First, they “inspect” the host’s eggs with their antennae and only then begin laying their own eggs. Usually, one egg of the parasite is laid in one egg of the host, but in larger eggs, more may be laid. Even when laying the egg, the female injects a secretion into the host’s egg that interrupts the development of the embryo, destroying its organs and systems. Externally, parasitized eggs change color to gray-black or black. Female wasps also kill a number of eggs by injuring them with their ovipositor and feeding on their contents.

Global and especially European policies in the field of agriculture are imposing restrictions on the use of pesticides, and therefore, alternative methods will increase their share in every plant protection system. Biological agents, such as Trichogramma, will be one of the most used means of pest control in the coming years.

Economic Benefits
Biological plant protection leads to reduced pest and disease attacks, better interaction and mutual natural protection of crops, increased efficiency of agricultural technologies, which ultimately leads to higher profits and ecologically clean production.

Strategic Benefits of Working with Entomophages
• Increase in yields by 20-30%.
• High-quality production
• The release of entomophages leads to the preservation and increase of populations of beneficial microorganisms and insects
• Preservation of the upper fertile soil layer
• Reduced costs for plant protection
• Does not lead to the appearance of resistant races and strains