Orchid pest: Myzus persicae

Peach aphid Myzus Persicae (Sulzer), also known as peach aphid, tobacco aphid, belongs to Homoptera, Aphididae. There are more than 300 kinds of host plants in China, including orchid, cherry blossom, hollyhock, plum blossom, peach, rose, pomegranate, begonia and so on. Adult aphids and nymphs suck plant sap on the back of the leaves, making the leaves curl, yellowing and drying up. Its excreta often induces coal fouling disease and affects plant growth. In addition, it can also spread the virus, causing orchids and other plant virus diseases.

Morphological features:

Winged viviparous female aphids: about 2mm body length, black head and chest, large abdominal color variation, green, yellowish green, brown or reddish brown, with light brown markings on the back. The antennae are 6-segmented, the ventral canal is slender and cylindrical, and the tail is slightly sunken in the center, bearing three pairs of curved lateral hairs.

Wingless viviparous female aphid: the body length is about 2mm, the body is fat, and it has two body colors: yellowish brown and reddish brown. The compound eyes are red, the feet are dark brown except for light green at the base, the forehead tumor and eye tumor are significant, the antennae are 6 segments, longer than the body, the abdominal canal is light black and slender, and the tail is conical, as long as the abdominal tube.

Nymph: similar to the female in the wingless fetus, but smaller and reddish in color.

Egg: long oval, long 1~1.2mm, first birth yellowish green, after lacquer black, glossy.

Occurrence pattern:

The algebra of peach aphid in one year varies from place to place. There are generally more than 10 generations in the north, but 3O~4O can occur in the south.

Generation. The life history of peach aphids is complex, some of them are full-periodic type (migration type), the other part is semi-periodic type (conservative type). The full-cycle peach aphid overwinters with eggs in branches, axils and cracks of peach trees and other drupe fruit trees in winter, hatches into dry mothers from mid-March to April next year, conducts parthenogenesis on flowers and trees, and reproduces for 2-3 generations. With the germination of flowers and trees, the damage is first clustered on the buds, and then the juice is sucked on the back of the leaves. In April and May, the winged aphid migrates and spreads, and the reproduction is numerous and the harm is serious. the female female produced by the winged aphid migrates back to the winter host, and only the wingless female aphid produces the wingless female aphid, and the winged male aphid produces the winged male aphid in the summer host, and the winged male aphid migrates back to the winter host, mating and laying eggs over the winter. The annual life cycle of half-periodic peach aphid is completed by parthenogenesis. The harm of neutralization in spring drought years is often very serious.

Prevention and control methods:

1. Carry out sanitary management of orchid nursery, eradicate weeds, cut off residual branches and leaves, and pay special attention to cutting or removing insect leaves and seedlings to prevent the spread of insect pests.

2. Most of the overwintering eggs hatch in March and can be sprayed with 2000 times of 50% phoxim EC or 80% enemy.

Dichlorvos EC 1O00 doubling liquid.

3. 1000 times of 40% dimethoate EC or 50% 8O0 solution of malathion EC can be used in the danger period of peach aphid. It is also possible to choose 25% deltamethrin EC 2000-300O times, 20% fenvalerate EC 20O0 times spray, aphid mist 50% wettable powder 2OOO times also has a better effect. (Liu Zhongjian)