The "killer" hidden in the leaves - the yellow thorn moth

I remember when I was a child, I had such an experience, when I went up the mountain to pick wild fruits, it seemed to be stung by something, the pain was unbearable, and then I turned back to check carefully, and found that there was a yellow-green, fat little bug on the leaves, and when I grew up, I knew that this little bug was called the yellow thorn moth. The following is a detailed introduction to this small bug.

[1] Distribution and hazards

The yellow-spined moth is a genus of Lepidoptera, a family of spiny moths, which is widely distributed and occurs in all fruit-producing areas of the country. Its diet is complex, mainly harmful pears, apples, apricots, begonias, peaches, dates, persimmons, willows, poplar and other fruit trees and forest tree species. The larvae eat the leaves, the young larvae eat the leaf flesh, the damaged leaves become a network, the larvae grow up to eat the leaves into a lack of moments, and when they are severe, they eat into light rods, resulting in secondary germination in autumn, affecting the growth and development of the tree.

[2] Pattern recognition

Adults Female moths are 15–17 mm long and have a wingspan of 35–39 mm, while males are 13–15 mm long and have a wingspan of 30–32 mm. The body is orange-yellow. The forewings are yellowish brown with a thin diagonal line extending from the apex to the middle chamber, the diagonal line is yellow on the inside and brown on the outside; in the brown part, there is a thin dark brown line extending from the neck angle to the middle of the posterior margin, and the middle ventricular part has a yellow-brown dot. The hindwings are greyish yellow.

Larvae Mature larvae are 19–25 mm long and large. The head is yellowish brown and hidden under the forebreast. The thorax is yellow-green, the body from the second section, each section of the dorsal line on both sides of the pair of thorns, to the third, fourth, tenth section of the large, the technical spines on the long black spiny hairs; the back of the body has a purple-brown large markings, the front and back are wide, a middle is narrow into a dumbbell shape, the back of the stub has 4 brown spots; there are 9 spines on each side of the body, there are 2 blue longitudinal stripes in the middle of the body, the valve line is light cyan, and the lower line of the valve is yellowish.

The eggs are oblate oval, slightly pointed at one end, 1.4–1.5 mm long and 0.9 mm wide, pale yellow, with a turtle-like marking on the egg membrane.

Pupae oval, coarse. Body length 13-15 mm. It is pale yellowish brown with a yellow back of the head and thorax, and a brown dorsal plate on the back of each segment of the abdomen. The cocoon is oval, hard, black-brown, with off-white irregular longitudinal stripes, very similar to a finch egg.

[3] Occurrence law

The yellow thorn moth occurs in 2 generations per year in the southwest region. The first generation of larvae hatches in mid-May and infest in early June, the second generation of larvae begins to be pest at the end of June, the most harmful in early July, and the second generation of larvae mature in late July and overwinter in cocoons on the branches.

[4] Prevention and control measures

(1) Pick the cocoon in autumn and winter, put it into the mesh, and the mesh hole shall be based on the fact that the adult yellow moth cannot escape, and the parasitic wasps should be protected and released.

(2) When the larval swarm is infested, remove the leaves and eliminate the larvae.

(3) During the adult occurrence period, use light to trap adult insects.

(4) During the larval occurrence period, 50% methamidophos 1000-1500 times liquid, 25% urea 3 2000-2500 times liquid or 1.8% avinocetacin 2000 times liquid and other agents are selected for prevention and control.