Occurrence and control of jujube armyworm

Jujube armyworm, also known as jujube falx wing small roll moth, commonly known as leaf sticking worm, is one of the important pests of jujube. To harm the larvae spinning and rolling leaves, roll the leaves in the shape of dumplings, or connect several leaves together with silk. The larvae also eat leaves and fruits, which has a great effect on the yield.

1. The occurrence regularity of this insect occurs for three generations a year, overwintering with pupae in the rough seams of branches and stems. The adults lie dormant during the day and come out at night and have strong phototaxis. They lay eggs 1 to 2 days after Eclosion, and the eggs are scattered on the smooth twigs and jujube strands. The egg stage is 10 to 25 days, and the peak of the first generation larvae is in early May. At this time, when the jujube tree sprouted and spread its leaves, the larvae first gnawed on the jujube buds and tender leaves, then spun silk to stick several leaves together and latent to feed on the leaves. Each larva can eat 6 to 8 jujube leaves, and a large number of sticky leaves in late May. The larvae became cocoon and pupated in the rolled leaves after maturing, and the first generation of adults appeared from early June to early July. After this generation, the eggs are mostly laid on both sides of the foliar midrib, and the egg period is 3 to 12 days. The second generation of larvae occurred from mid-June to late July, just before and after flowering, harming leaves, flowers and young fruits. The third generation larvae occurred in the fruit coloring period from late July to mid-October, causing damage to leaves and fruits, especially from late August to early September. After the first ten days of September, the larvae matured one after another and pupated under the bark and in the tree hole.

2. Control methods 1. Before pupation of mature larvae in early September, grass handles were bundled on the branches to induce larvae to pupate and survive the winter. In winter or early spring of the next year, combined with scraping bark, Cordyceps sinensis will be removed and concentrated treatment, the effect is better.

two。 The peak hatching period of each generation of larvae is the key period of chemical control, especially the control of the first generation larvae. Because of the neat occurrence of this generation of pests, the effect of chemical control is better. When the tender tip of jujube reaches about 3 cm (that is, the peak hatching period of the first generation larvae), spraying 1000 to 2000 times of fenitrothion EC, 50% dibromophosphorus EC, 4000 times of deltamethrin EC, 3000 times of fenvalerate or 1500 times of dichlorvos have good results. If the occurrence is serious, the jujube can be sprayed for the second time before and after budding. At this time, the second generation larvae harm the buds, flowers and young fruits. If the spraying is not timely, it will cause dead flowers and fruit drop, and seriously affect the yield. In addition, spraying 2000 times of 50% parathion during the occurrence of adults in early spring has a killing effect on both adults and eggs.

3. Adults have phototaxis and can be set up with black light to trap and kill adults.