Cotton aphids are widespread in the world and are capable of affecting more than 300 plants; in greenhouses, it is especially dangerous for cucumber.
The feeding of the insect on the underside of the leaves and young shoots causes them to turn yellow, twist and shrink. Also, this pest can affect flowers and fruits. The pest reproduces rapidly, increasing its population on the affected plants, which leads to a decrease in their yield, weakening and death. Sugary fungi can develop on sugary isolates of aphids, which prevent the normal passage of physiological processes in the host plant: transpiration, respiration and photosynthesis. Aphids carry a variety of viral diseases, among them the cucumber mosaic virus (CMV). The cucumber mosaic virus can affect various crops and can reduce the yield of cucumbers by half.
The wingless female aphid has a pear-shaped body, 1-2.1 mm long and 0.9-1.5 wide. The color of the body is matte and varies from yellow-green to dark green, almost black. The head and chest are darker, but some individuals do not differ in the coloration of these parts of the body. Antennal hillocks on the head are absent, the forehead slightly convex. Antennae yellow, composed of 6 segments, reaching 75% of body length. Spitz of the last antennal segment has three apical setae. The length of pinnacle is equal to the third antennal segment. Eyes brown-brown. On marginal abdominal segments 1 and 6 are marginal tubercles. The legs are usually yellow, and the tops of the hips, shins and legs are black. The base of the proboscis is light, the last two segments are dark. Juice tubules slightly expanded at the base, cylindrical, black, 2 times longer than the tail and make up about 20% of the body length. The finger-shaped tail has an interception at the base and three pairs of lateral hairs. The color of the tail is usually the same as the body. Spiracles are oval.
The winged female has an elongated body. The color of the head, chest, juice tubes, ends of the legs and legs is black. Basins of all legs and apex of hind femorae of black and brown color. The abdomen is yellow-green, at the apex darker, on the sides has rectangular dark brown spots. There are dark strips on the dorsal side of the abdomen. Antennae longer than a wingless individual. The forehead between the antennae is triangular in shape. Eyes are brownish-claret. Two eyes are adjacent to the facetted eyes, the third is between the antennae on the forehead. The location of the rhinarium on the third segment may be different on the right and left antennae. The number of the third segment's fusarium ranged from 5 to 12. On the 6th antennal joint there is one main and five additional rinaries. Tail of brown color, finger-shaped with three pairs of lateral hairs, slightly beyond the juice tubes.
It develops as not a full cyclic species, which can be associated with loss of the primary or secondary host plant. Reproduction occurs only in parthenogenetic way, live birth. The life cycle of a wingless female has 4 periods: preimaginal, maturation, reproductive, post-productive. The pest life expectancy is about 17-22 days, of which the reproductive period lasts about 14 days. The wingless female is able to breed up to 85 larvae, and the winged female is about 2 times smaller. The greater the density of the colony, the higher the percentage of winged females. They fly to other plants where they create new colonies, which consist mainly of wingless females. In a greenhouse for a year aphids can give 10-18 generations. Cotton hats are hibernating in the north of their range in greenhouses, and in the south - on weeds. In spring, the first generation of the pest begins feeding and multiplying mainly on weeds when the temperature rises above 5 ° C. In May and early June, the insect migrates to cultivated plants. The optimal conditions for pest are: temperature 16-25 °C and humidity 60-85%. High temperature (above 25 °C) adversely affects the growth of the population.
For preventive purposes around greenhouses it is necessary to destroy the weed vegetation on which the aphids winter and multiply.
The pest has many natural predators that can control it. In the conditions of closed ground, such entomophages as: Aphidius colemani, Chrysoperla carnea, Adalia bipunctata are used. Pest colonies have a spatial structure, in which there are sexually mature females in their center, around them are larvae of different instars, and on the periphery old females of post-productive instar. Polyphagous predators attack the colony in the first place to destroy old individuals that are not capable of reproduction, whereas parasites of aphids specialize in larval instars and females of generative age.