Pest Type: Sugar Beet Pest
Row: Equine – Homoptera
Family: Aphids – Aphididae
It is found everywhere, especially numerous in the western regions. In addition to beets, it damages legumes, nightshade, Asteraceae, pumpkin, and other cultivated plants and weeds.
The wingless parthenogenic female 1.8-2.5 mm long has an oval body, black with a green-brown tint, covered with a faint waxy coating; juice tubes twice as long as a ponytail; antennae and legs pale yellow; tubes, tail, and paws black-brown; proboscis reaches coxae of middle legs. Winged female 1.4-2.0 mm in size; head and chest are black, shiny; abdomen black and green, front hips white, black antennae. Amphigone female, 2.2-2.7 mm, wingless, black-blue or dull green, in a gray gun; around the juice tubes and between them a reddish pigment; hind tibia black, tail conical.
The male is 2-2.5 mm in size, winged, with a black abdomen, large eyes, long legs, and antennae. The egg is 0.5-0.6 mm long, oval, only laid – yellow-green, later black, shiny.
The view is migratory. Fertilized eggs hibernate on shoots at the base of the European euonymus buds, more rarely warty, viburnum and jasmine.
In April, at an average temperature of 7-9 ° C, larvae are reborn from eggs that have hibernated, after 12-14 days of feeding on buds and leaves turn into wingless females. Flightless females breed parthenogenously, reviving daily 5-8 larvae, a total of 50-70 on average. On primary fodder plants, 3-4 generations of aphids develop until the growth of the bushes is complete. In late May and early June, winged parthenogenic females appear that scatter in search of intermediate herbaceous plants and, in particular, sugar beets. The appearance of winged females and their migration are due to deterioration in the quality of food due to the drying of shoots on the bushes.
Migration can be complete and partial (optional), in which part of the aphids is on the primary host all season, until the appearance of amphibole generations. First, the aphids populate beetroot plantings, which, earlier than the beets of the first year, begin their development. On beets and other herbaceous plants, aphids quickly multiply by parthenogenesis until autumn, giving 8-10 or more generations of wingless and winged aphids during this time. Thanks to the latter, aphids quickly spread throughout the crop. At a temperature of 23-28 ° C and relative humidity of at least 60-80%, one generation develops in 10-14 days.
The highest population of plants is usually in the first half of July. Winged females fly over to the euonymus, jasmine, viburnum, where larvae are regenerated, which turn into wingless amphigone females. Wingless revive larvae that turn into winged males. Winged males fly to the bush, after mating, the females lay 3-7 eggs on shoots at the base of the kidneys and remain until the spring of next year.
Aphids suck the juice from leaves, populating them from the underside. Damaged leaves are deformed, curled in the longitudinal direction, then fade and dry. Significant harm to the aphid is done by the testes of beets, in which, in addition to the leaves, the shoots are damaged, which leads to their curvature. The act of sucking is accompanied by the release of saliva enzymes, which, getting into plant tissues, cause plasmolysis of cells and turn starch into sugar. Damaged plants are in a painful condition for a long time due to the toxic effects of saliva enzymes even after the destruction of the pest. The damaged plant lags behind in growth, its sugar content decreases (up to 0.7%) and the mass of root crops (up to 30%), the seed yield decreases and its quality deteriorates. Often, aphids are a carrier of beet virus mosaic disease.
Aphids are limited by many predators and some coma chiparasites. Adults and larvae feed on coccinellids, goldfish, ground beetles, predatory mites, spiders, predatory gall midges, etc.
In years with wet summers, aphid mass mortality is observed. Larvae and adults washed away by rain on the soil usually die.
Control measures. Weed control. Restrictions planting viburnum, jasmine, euonymus. If the pest populates more than 5% of the plants in May, more than 10% in June and 15% in July, the crops must be treated with insecticides. However, if the ratio of pest: predator is 20 … 30: 1, it is not advisable to use insecticides.