Occurrence and control of jujube pest grass paramecium and jujube gall mite

Occurrence and control of jujube pest grass paramecium and jujube gall mite

1 paramecium

Belongs to the Homoptera Coccidae jujube pest, also known as tree lice, grass shoe insect. It is widely distributed in China, such as Hebei, Shanxi, Shandong, Shaanxi, Henan and other provinces (regions). In early spring, nymphs gather and suck sap on the shoots, resulting in bud withering, tree decay, and a large number of falling flowers and fruits.

1.1 morphological characteristics. The egg is oval, the first birth is yellowish, and then brown. Nymphs are similar to female adults with small size and dark color. Male pupa cylindric, brownish red, ca. 5 mm long, covered with white woolly. The female is wingless, flat-oval, about 10 mm long, like straw sandals, reddish brown, covered with white wax powder. Antennae filiform, black. It's black. The mouthparts are dark brown, between the feet. The male is purplish red, 5 ~ 6mm in length and 10mm in wingspan. Wings 1 pair, light black, compound eyes spherical, black.

1.2 Ecological habits. The worm overwintered with its eggs in the soil, and in the early spring of the following year, with the rise of temperature, the eggs hatched into nymphs, and at first the nymphs stayed in the oocyst. When the sap flowed, the nymphs broke the sac and unearthed the tree. March is the peak unearthed period. Nymphs usually move around noon when the temperature is high, and go up to the tree to absorb juice. After the nymph molted for the first time in early April, the nymph body enlarged and secreted wax powder. After the nymph molted for the third time from April to May, the male nymph pupated in the skin seam and tree hole, and the male adult emerged for about 10 days, and the female nymph reached sexual maturity after 3 times molting. After mating, the male adult dies. From May to June, the female went down to the tree and drilled into the underground soil layer of 5 ~ 7 cm, secreted white fluffy oocysts, laid eggs in them, and spent the summer and winter.

1.3 Prevention and control methods. First, artificial prevention and control. Do a good job of soil preparation in the field and dig out oocysts to kill insects. At the same time, combined with tending management, withered grass and withered leaves were removed and burned centrally, so as to reduce the insect population density, reduce the insect source and reduce the harm of the insect. The second is biological control. Protect natural enemies such as red ring ladybug and reduce population density. The third is chemical control. During the peak incubation period of nymphs, spray 30-40 times of machine oil emulsion, 400-500 times of 25% carbaryl wettable powder, or 6 000 times of 20% fenvalerate plus 1 500 times of 40% omethoate.

2 jujube gall mite

Belongs to tick mite order gall mite family jujube pest, also known as jujube mite, jujube tick. Henan, Gansu, Ningxia, Anhui, Zhejiang and other provinces (regions) are distributed. After the jujube tree was killed, the leaves were curled, the leaves were gray, the flowers, fruits and leaves fell seriously, and rust spots appeared on the fruit surface, resulting in a decrease in fruit yield and quality.

2.1 morphological characteristics. Ovoid, milky white, smooth, transparent. If the mite is carrot-shaped, smaller than the adult mite, milky white or yellowish, with 2 pairs of nodes, the abdomen is smooth, slightly striated, and the tail is slightly pointed. The adult mite is carrot-shaped with a length of 0.15 mm. It is milky white at first, then light yellow, translucent and shiny, with 2 pairs of head and chest appendages, of which 1 pair of chelate limbs (feather claws) is short and thick; the chelate claws are small, the apex is obtusely round, and there is a brown spot on the front of the basal ganglia. The beak is needle-shaped, located behind the chelate limbs under the head. The back of the chest is wide and nearly round, and there are many horizontal striations in the abdomen.

2.2 Ecological habits. The insect overwinters as adult mites and nymph mites in jujube scales or skins of jujube branches. The insect has the advantages of rapid reproduction, strong resistance, rapid spread, wide distribution and difficult to prevent and control. When the jujube bud germinates in spring, the overwintering mite begins to move and feed, and the density is small, and it is mostly concentrated on both sides of the three main veins on the back of the jujube leaf, and the activity radius is very small, but it has the habit of migrating by the wind, and the speed of spreading damage is fast. The damage reached its peak in June. Both sides of the leaves can be harmful, but mainly on the back, the damaged leaves curl longitudinally upward, the color of the leaves change from green to gray, and the leaves are brittle. When the air temperature is high and the atmospheric humidity is relatively low, it is not conducive to the development of the insect. In the high temperature weather from July to August, the mite mites transferred from leaves to scale buds over the summer, and the number of mites on leaves decreased. In September, the reproduction rate of the mite decreased and the population density decreased. After the end of September, the mite stung and overwintered.

2.3 Prevention and control measures. First, do a good job in seedling quarantine to prevent the spread of the insect. The second is to do a good job of watering, weeding, fertilization and other management and protection work, to enhance the tree potential, in order to improve the insect resistance of seedlings. At the same time, combined with winter pruning, remove disease and insect branches, scrape off the old warped skin, concentrate on burning, and eliminate the source of overwintering insects. The third is to spray 3 ~ 5 Baume stone sulfur mixture once before jujube germination to kill overwintering adult mites and aged nymph mites. In the first and middle of May, spray 20% of acarbazine 2000 times, 2% avermectin 4000 times, 50% aphids 1000 times or 20% acaridins 3000 times. The fourth is to protect and make use of natural enemies, such as ladybugs, flower bugs, etc., to reduce the harm of the insect.