The boat-shaped caterpillar is Lepidoptera, and the moth family. Also known as the apple community moth. The worm is almost all over the country. The main hazards are sea otters, cherry blossoms, prunus triloba, purple peony, hawthorn, plum, willow and other trees. Larvae harm the leaves and can eat the leaves when they are severe.
Morphological characteristics The adult body is about 25 millimeters long and the wingspan is about 50 millimeters. Yellowish white. There are no obvious wave patterns on the forewings, six black round spots on the outer edges, and silver-gray and half-brown stripes on the center near the base. The hind wings are light yellow and the outer edges are mixed with dark brown patches. Ovoid spherical, approximately 1 mm in diameter, pale green or yellowish-white when hatched when newly hatched. The eggs are arranged neatly into blocks. The larvae are about 50 millimeters long and mature larvae. The head is yellow and shiny. The back of the chest is purple-black and the belly is purple. There are yellow-white hairs on the body. There is a slightly yellow vertical line on the body side. Young larvae are fuchsia. At rest, the head, chest, and tail are raised like boats, so they are called boat-shaped caterpillars. The carcass is 20 to 23 mm long and dark reddish brown. Engraved with a dense body, with 4 or 6 hip spines, 2 large in the middle and 2 in the side, which are not obvious or disappear.
The law of occurrence occurs one generation in a year. Wintering in a 1 to 18 cm soil under a canopy. Jubilee from early July to early August, and the middle and late July is the peak of emergence. The adult insects are nocturnal, and the phototaxis is strong. Eggs are often produced on the back of leaves, arranged in a single layer, and densely integrated. The egg period is about 7 days. In early August, the larvae hatch, the newly hatched larvae cluster on the back of the leaves, and the foraging leaves and leaves are grayish white and transparent mesh, which spreads and harms when they grow up. They are inactive during the day and feed sooner or later. They often eat away the pruning and the leaves of the whole tree, leaving only the petiole. . The larvae are frightened by the habit of drooping silk. The larval stage is from mid-August to mid-September. The larvae were 5th instar and the larvae were on average 40 days old.
Control methods 1. In the winter and spring, the tree hole is deepened and dug soils are dug, concentrated collection and treatment are performed to reduce the source of insects. 2. Light traps adult worms. Due to the strong phototaxis of adult pests, black light can be set in adult and eclosion phases in July and August to trap and kill adult worms. 3. Utilizing the clustered and frightened silk drooping habits of newly hatched larvae, few trees and few insects, insects, larvae and vibrating tree crowns can be removed to kill floor-to-face larvae. 4. Chemical control. The young larvae spray 1000 times 20% larvae urea suspension. The tree has a large amount of insects and can inject 500 to 1000 times of Bt emulsion containing more than 10 billion spores per ml to kill older instar larvae. Insect volume is too large, if necessary, can be sprayed with 80% dichlorvos EC 1000 times or 90% crystal trichlorfon 1500 times or 20% chrysanthemum EC 2000 times. 5. Artificial release of egg parasitoids.
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