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Diapausing trichogramma - economic alternative
01 | 05 | 2018
TRICHOGRAMMA is a natural entomophage insect that lives in nature and helps people fight against a number of pests. In biolaboratories it is bred on eggs of natural species of insect-owners (mainly on egg products of cereal moth). The small insect of brown color, which belongs to the family of trichogramma of a number of membranes, destroys oviposition of more than 80 species of pests. The trichogramma develops inside the eggs of insect pests affected by it. The eggs affected by trichogramma acquire dark color in a few days.
The larvae are only parasites, and adult insects feed on nectar and dew.
In the classical application of an ordinary trichogramma to fight pests of agricultural crops, trichogramma is released three or more times with different norms depending on the number of pests: leaf-eating owlet moths and cut worms, seedworm (Laspeyresia), brown oak tortrix, European corn borer, moth of the family Crambidae, oviposition density, and cultures on which trichogramma is released. They were carried out manually, with special devices on the ground or by air, each issue every 5-7 days. In past years, with large unlimited material resources, the trichogramma application was carried out using the aircraft AN. However, due to the rising cost of this method of application, a significant increase in costs, there was a task to reduce the cost of trichogramma application, as well as reduce it to one application, so that it could significantly reduce the cost of trichogramma. In addition, both in Ukraine and in other states, the stock culture of the trichogramma was replenished in minimal quantities from natural stations. To solve a very urgent issue of reducing trichogramma application from three and more times to only one, the specialists of Cherkassy Scientific and Production Center for Biological Plant Protection, LLC developed a unique technology for the production of diapausing trichogramma, which made it possible to apply it on an area of over 350 thousand hectares.
For example. The flight and oviposition of the Crambidae moth lasts for at least 25-30 days. According to the old scheme of introducing trichogramma in high-stem cultures (corn, sunflower, hemp, sorghum, millet, garden) it was necessary to apply it 3-4 times manually in an ineffective way. With this, the harm done to the damage from caterpillars ranged from 60-100% of plants in the middle and strong stages. Therefore, the task set for the specialists of “Cherkasybiozahyst”, LLC, the Scientific Research Institute, was to make a one-time application with the help of economical small aviation (‘Bekas’ hang-glider) with special devices for trichogramma application equipped with GPS-navigators, so that the oviposition-parasite in a diapausing state effectively works throughout the entire oviposition (about a month) on high-stem plant plants with an efficiency equal to or exceeding 2-3 times the application of the ordinary (normal) trichogramma.
For more than 15 years, specialists of ‘Cherkasybiozahyst’, LLC have been tested in different cultures with different rules for trichogramma application, to remove the harmfulness of the European corn borer and achieve maximum efficiency, and came to the conclusion that trichogramma application at the beginning of the pest oviposition should be reborn for 20%, during the mass oviposition for 60% and by the end of oviposition it’ll be 20% of trichogramma.
This became possible only with the use of a diapausing trichogramma with different periods of rebirth. The ratio of this trichogramma is applied irrespective of the norm of trichogramma application. Having achieved the greatest stable efficiency with one-time application of diapausing trichogramma fighting stem butterflies in the crops of corn, sunflower, and millet, however, due to subjective and objective reasons, and changes in climatic conditions (there is an increase in positive temperatures) there have been favorable conditions for mass emergence of new species of pests that were typical for the Asian countries; this is a cotton budworm, which is gaining popularity, and produces two generations in an era of forest and steppe. The harmfulness of the Silver Y moth, which in our conditions gives 3 generations, has increased. The question was how to protect corn, sunflower, millet from these three main pests, because they have a different period of flying, oviposition, caterpillars’ rebirth, and different nocuousness.
The solution of this additional issue with minimal cost and maximum efficiency was made possible due to the methods of production developed by our specialists of ‘Cherkasybiozahyst’ and use of diapausing trichogramma.
The technology of introducing such trichogramma and protecting agricultural crops takes into account the predicted amount of egg production per unit area, the period of flying and oviposition of the pest, the technology of cultivating crops, increasing the rate of insertion of trichogramma at a single dose.
As our practical (more than 50 years old) experience of using trichogramma on crops, for example on corn, shows, the whole yield of this crop is preserved for 20 to 45 percent from the most harmful pests, namely the European corn borer, cotton bollworm, Silver Y.
Having spent 100-120 hryvnias for its introduction per one hectare, minimum 1-1,5 tons of corn grain is stored. At today’s prices this is an additional income of 4-5 thousand UAH from each hectare to thefarm business, which compensates for the costs of 1 hectare of sowing material and herbicides!
Trichogramma is one of the most important steps towards full-scale production of organic products.