American white butterfly (ABM)

The American white butterfly (ABM) is a dangerous quarantine pest that damages up to 230 species of tree-shrub and herbaceous plants, including apple and other fruit crops. Eating the leaves completely, the pest sharply reduces the yield of trees that do not grow, lose winter resistance and may die.

It spreads mainly from infected regions mostly with planting material, vehicles with containers, packaging material, with fruits and berries.

The butterfly is quite large. Wingspan of males 25-30 mm, females 25-36 mm, snow-white in color, sometimes with black or brown dots on the wings. Antennae are black with a white coating, comb-like in the male, thread-like in the female. The body of the butterfly is covered with thick white hairs.

The flight of butterflies occurs at the end of the flowering of the apple tree, the flight of the butterfly can last up to two months.

Females, after mating, lay relatively large eggs of green, yellow-green or golden-yellow color with a blue tint, up to 0.5 - 0.7 mm in diameter. In females that have not laid eggs, the abdomen is green from translucent eggs.

As the embryo develops, the color of the eggs changes to dirty gray. Eggs are laid on the underside of the leaf in bunches, from 100 to 600 pieces. One female lays up to 1500 eggs, females of the second generation are more fertile: each of them lays up to 2500 eggs. Egg clutches are covered with a thin layer of white hairs from the tip of the female's abdomen. Embryonic development lasts from 5-6 to 9-15 days, depending on the temperature.

The caterpillar of the first instar is green, in tubercles, bears bristles and hairs on its body. Caterpillars of the first three instars are pale yellow in color, but darken after each molt. In total, caterpillars usually have 6 ages (sometimes 7 - 8).

The last instar caterpillar is velvety brown with black warts on the body, a lemon-yellow stripe with orange warts runs along the sides of its body. The caterpillar is heavily covered with long hairs. The length of an adult caterpillar reaches 30-40 mm. Fourth-instar caterpillars live in colonies, forming large web nests, often entwining entire trees with their webs. Starting at the age of 5, the caterpillars crawl and lead a secluded lifestyle. Caterpillar stage 40-50 days.

The pupa is 8-15 mm long, in a liquid gray loose cobweb cocoon of hairs, at first its color is pale yellow, but later it acquires a dark brown color. The development of all stages depends on temperature and relative humidity. The pupal stage lasts 15-20 days, the second generation of butterflies takes place from mid-July to the end of August. Caterpillars of the second generation are more voracious and cause damage in August-September. After finishing feeding, they pupate in wintering places. Pupae hibernate under the dead bark of trunks and skeletal branches of trees, under plant remains, in weed stems, in cracks in fences and buildings, and in the surface layer of the soil.

Protection measures

1. Strict adherence to quarantine measures in areas free of the American white butterfly, in particular, disinfection of planting material. Periodic survey of orchards and imposition of quarantine on farms where the American white butterfly has been detected. It is extremely important to fight against the pest, its detection and destruction during the first generation. Already the second generation is much more numerous and brings much more losses.

2. Timely detection, collection and destruction of web nests with caterpillars. Digging the soil in the trunk circles, cleaning trees from dead bark and collecting fallen leaves, followed by destruction together with caterpillars in the fall after November or early spring. These measures significantly reduce the wintering stock of the pest.

3. Treatment of the garden and other places for reborn caterpillars with drugs:

• Imexab™ 10g/10l

Biological insectoacaricide for effective protection of garden, berry and ornamental crops from pests. The action of the drug Imeksab™ is aimed at blocking the neuromuscular interaction in the organism of the pest, which is achieved by blocking the transmission of nerve impulses. Thus, after 4-5 hours after application, pests stop feeding and moving, as a result of which the pest dies.

• Bacitoxin 10g/10l

Biological insecticide for protecting crops from lepidopteran pests. It is recommended to use to destroy the caterpillars of lepidopterous pests (whiteflies; cabbage, apple and fruit moths; American white butterfly; scoop; firefly; leafroller; corn and meadow butterfly, sawflies, etc.). on agricultural, garden, decorative crops and flowers in open and closed ground. Biological preparation is used to fight against larvae of different age groups and adults of pests.

For better penetration of drugs through the cobwebs, it is necessary to add the adjuvant Izomax™.

• Izomax™ 2ml/10l

Highly effective concentrated adjuvant-surfactant, designed for better application, retention and penetration of working solutions on the surface of plants.