Control of Myrica rubra

There is a great difference between male and female morphology of adult bayberry coir moth. The male adult is 15-20 mm long, with a wingspan of 30-35 mm, dark brown, with 3-5 translucent markings near the outer edge of the forewing and brown hind wings. The female adult is wingless, shaped like a maggot, about 26 mm long, with a dirty white body, an enlarged abdomen and a small tail.

When the larvae grow up, the female larvae are also obviously different from the male ones. The female larvae grow up with a body length of 25mm to 40mm, the head is reddish brown, the chest dorsal plate is grayish brown, and the abdomen is dark brown; when the male larvae grow up, the body length is 17mm 24mm, the head is yellowish brown, and the chest and abdomen are grayish brown. The egg is oval and yellowish. The pupa is about 30 mm long and reddish brown. The protective capsule is 40-60 mm long, with large broken leaves and a small number of branches outside the capsule, and the branches are not arranged neatly. Living habits: in the middle and lower reaches of the Yangtze River, the insect produces one generation a year, and occasionally two generations of adults appear from August to September, and they also lay eggs and hatch, but their larvae often can not survive the winter. Generally speaking, most of them overwintered with mature larvae hanging on the branches in the protective bag. Pupation began from late April to early May, and adults began to Eclosion in early May. Most of the adults emerged around midnight, and the male moths were active and phototactic after dusk. The female moth began to lay eggs in the middle of May, and the eggs were laid in the pupa shell in the protective capsule, with an average fecundity of about 2600 eggs. The larvae began to hatch in early June, and the newly hatched larvae chewed mesophyll, residual epidermis and less food. The food intake increased sharply after 3 years old and 4 years old, and swallowed a lot of leaves. The damage is the heaviest from August to September, and the larvae can spin silk and hang on the branches and float away with the wind, so it is commonly known as "hanging ghosts". The larvae to the light, on the sweet-scented osmanthus gathered in the branches and tree tops to do harm. When the larvae matured, they pupated in the protective capsule and overwintered with silk attached to the leaves. Generally, the damage is serious when it is dry and hot in summer, and it is not easy to cause disasters in years with a lot of rainfall. Prevention and control methods: 1. Combined with pruning, remove the protective bag at any time. two。 Trap and kill male adults with black lights or sex information hormones. 3. To protect natural enemies, coir moth larvae are often parasitized by a variety of natural enemies, such as tumor wasps, wasps and parasitic flies, and the parasitism rate can be as high as 50%. Therefore, it is necessary to use fewer chemical pesticides with a wide insecticidal spectrum and more specific microbial preparations, such as nuclear polyhedrosis virus preparations, cyanobacteria and Bacillus preparations, which not only have a high killing rate to contemporary larvae, but also can be passed on to the next generation and avoid pollution. 4. If the population density is large and the occurrence range is wide, we can choose 90% trichlorfon 1000 times, 50% marathon emulsion 1000 times and 50% imidophos 800 times, all of which have good results. With the increase of the age of the insect, the concentration of the spray will also increase, for example, the trichlorfon needs 500 to 800 times liquid. If you want a large amount of spray, you must make the protective bag fully wet. The best spraying time is in the evening when the larvae are active, and then in the early morning. The insect has obvious aversion and strong hunger tolerance. It refuses to eat after spraying some control drugs (including some microbial preparations). Its hunger tolerance can be up to three weeks, so it is often necessary to spray several times before it can be effective.