Potato moth Phthorimae operculella Zeller is a dangerous quarantine pest that is widespread on all continents where potatoes are grown
The resettlement of potato moths occurred with infected tubers, which were exported first from the regions of South America, and then from the secondary foci of the pest (according to the FSBI VNIIKR).
In the Russian Federation, potato moth was discovered in 1981-1983. in different points of the Black Sea coast of the Caucasus, from Anapa to Adler.
Fodder plants for potato moths are cultivated and wild plants of the nightshade family: potatoes, eggplant, tobacco, physalis, henbane, and dope. On them, the pest fully develops and gives prolific offspring. To a lesser extent, pepper, tomatoes and other representatives of nightshade are damaged. In places favorable for the growth and development of the pest, especially in tropical countries, the harvested crop can be completely destroyed by this pest.
The potato moth develops without diapause. The lower threshold of development is + 10 ° С, the upper one is + 35 ° С. Development occurs continuously within these temperature ranges. At temperatures below -4 ° C and above + 36 ° C, all stages of development die. The timing of development is highly dependent on temperature. At an optimal temperature of 20-27 ° C, one generation of potato moth develops within 28-30 days, and at 8-20 ° C, -120-150 days.
In storage facilities with a controlled temperature with an optimal storage regime of + 3 ... + 5 ° C within 4-5 months, all stages of the pest's development die or become unviable. Butterflies fly out in early spring and are found until the end of October. In summer, the activity of butterflies is observed at dusk, immediately after sunset and before sunrise. In autumn, summer occurs in the daytime, it is especially intense at 18 ° C. Butterflies do not fly at temperatures below 13 ° C.
The imago lives for 10-12 days. Females lay on average 60-110 eggs, maximum - 400 eggs. The maximum number of butterflies is observed before harvesting potatoes.
Potato moth leaves for wintering at different stages of development, however, only caterpillars of the fourth age and pupae that have finished feeding can overwinter. The pest overwinters in plant debris, in soil at a depth of 5-7 cm, in storage.
The harmful stage is the caterpillar, which damages the leaves, stem and tubers. Planting tubers are damaged only where they come to the surface or soil cracks are located above them. In the Russian Federation, potato moth does not affect the potato yield in the field. The main harm is done during the storage period of tubers, especially in storages with uncontrolled temperature at 10-15 ° С and higher. Tubers with passages and excrement of the pest under the skin and in the pulp are poorly stored, more damaged by diseases, lose their presentation and quality.
Growing nightshade crops, a set of organizational, economic and agricultural measures should be observed:
- crop rotation with crop rotation for at least three years, with obligatory spatial isolation of new crops from old fields and vegetable stores for at least one kilometer;
- systematic destruction of self-seeding of cultivated and wild-growing solanaceous plants in the outbreak of potato moth;
- for planting potatoes, only healthy seed should be used. Planting in warm soil (heating depth 14 cm). When growing, plants should be regularly hilled, avoiding exposing the tubers, watering;
- harvesting should be carried out as soon as possible at the beginning of the yellowing of the tops. 5-7 days before harvesting the potatoes, it is necessary to mow and destroy the aboveground part. Dug out potatoes should be removed from the site every day, damaged substandard tubers and other plant residues should be immediately destroyed.
When planting and during the growing season of potatoes, it is imperative to take protective measures against the pest complex, which includes treating tubers with insecticides registered for these purposes in the “State Catalog of Pesticides and Agrochemicals” and spraying them according to the rules and regulations for their use during the period from beginning of colonization by the Colorado potato beetle (late April - early May) until the end of flowering of potatoes with an interval of 10-14 days. In case of repeated treatments during the same season, to prevent the development of resistance in pests, insecticides from different classes should be alternated or ready-made mixed preparations should be used.
Potatoes should be stored at a temperature of + 3 ... + 5 ° С - below the pest development threshold (+10 ° С). Equip the potato storage in such a way as to prevent the potato moth butterflies from flying. Before laying for storage, it is necessary to fumigate the premises with preparations based on aluminum phosphide and treat the potato tubers with a 1% solution of the microbiological preparation Lepidocid P, SK, SK-M by immersing the tubers in a 1% suspension of the preparation for 4-5 minutes at the rate of 100 liters per 15 tons of potatoes, after which they are dried in the shade and stored.
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