morphological character
Adult male adult: The body length is about 20 mm, the front wing is brown, and there are 4 or 5 wavy transverse bands, the outer edge is dark band, and there is a black spot in the center of the cavity. Female insect: It is about 25mm long, with gray front wings and a dark brown spot between every two veins. There are tawny tufts at the end of the abdomen. The oval is slightly flat, with a diameter of 1.3mm, and apricot yellow is produced at first. Hundreds to thousands of eggs are laid together to form an egg mass, which is covered with thick yellow-brown fluff. When the larva matures, it is 50 ~ 70 mm long, with yellow-brown head and open black stripes. Hair tumors from the chest to the second segment of the abdomen are blue, and 7 pairs of hair tumors from the third to the ninth segment of the abdomen are red.
Biological properties
1 generation occurs in 1 year, and overwinters as eggs in cracks in stones or cavities on the back of tree trunks. The overwintering eggs hatch in May of the following year, and the newly hatched larvae have the habit of gathering and dispersing when they grow up. In early and middle July, mature larvae cocoon and pupate in the hollow parts of trunk, branches and dead leaves. Mid-July is the adult stage. Male moths are good at flying and often fly in groups during the day. Most of the eggs are laid on the shady side of the branches in the tree, and each female lays 1 ~ 2 eggs, each with hundreds of eggs, and the tail of the female moth's abdomen is covered with yellow-brown scales.
Preventive and control measures
(1) Scratching eggs
Scratch eggs in autumn and winter.
(2) Trapping and killing
Light lures adults; Sokcho trapped and killed the larvae on the trunk, and burned them centrally.
(3) Chemical control
According to the habit of larvae getting off the tree during the day and getting on the tree at night, a poison ring is coated on the base of the trunk to kill the larvae. Before the 3rd instar, the larvae were killed with conventional chemicals. 50% phoxim EC and 50% cartap EC 1000 times solution can be used to kill the overwintering larvae of willow moth.
(4) Biological control
Protect insect-eating birds, parasitic bees and flies, and use biological agents such as Bt and Cordyceps.