Spodoptera litura

Spruce yellow roll moth [Archipsoporanus (Linnaeus)], alias pine bud leaf roll moth, pine thick leaf roll moth, belongs to the family Lepidoptera. It is distributed in Heilongjiang, Liaoning, Central and South China, and can harm Pinus elliottii, loblolly pine, Masson pine, Korean pine, spruce and juniper.

The damage characteristics of larvae eat axillary buds, flower buds and male flowers, eat needles, affecting tree growth and seed yield.

Morphological characteristics

The adult has a length of 10-12mm and a wingspan of 22-30mm. The male moth has a reddish brown head and chest and a brown abdomen, while the female moth has yellowish brown forewings with many brown ornaments.

The egg is oval, about 0.96mm long, milky white at first birth and gradually turning yellow. The egg masses are arranged in a pile of scales.

The larvae are 20mm in body length, light green, black-brown head, orange-brown edge on the front chest dorsal plate, and light yellow supraanal plate.

The pupa is 15-16mm long and turns yellowish green at the beginning of pupa, and then turns brown gradually. There are 8 gluteal spines and the end strength is curled.

The occurrence regularity of 1-2 generations in Northeast China and 2-3 generations in Zhejiang Province overwintered with 2-3 instar larvae on the axillary buds of branches. In the following year, he began to feed actively from late March to early April, often eating the flower buds into an oval depression, and then continued to eat male cones. When feeding on needles, he often spun silk to fix several bunches of needles together, and glued the middle part to the branches and stems, in which he ate heart leaves, ate a large amount of leaves, and often transferred the damage. In late April, the larvae silked 3-5 male inflorescences into a bundle and pupated in the inner or injured needles. The pupa stage is 5-10 days, and the adults emerge at the beginning of May. The second generation of adults appeared in the middle and late August.

Adults lie dormant during the day, mate that night, and have phototaxis. The eggs are mostly laid on the trunk epidermis, and each female moth lays 205-410 eggs. The newly hatched larvae are good at crawling and have the habit of spinning and sagging. The larva is 4th instar and lasts for 20-25 days.

Prevention and cure method

(1) Agricultural prevention and control.

Build mixed forest, strengthen tending, enhance tree potential and reduce damage; combined with seed collection, cut off axillary buds and reduce the source of overwintering insects.

(2) black light trap.

(3) Pesticide control.

When the larvae were sprayed with 90% crystal trichlorfon, 40% dimethoate 2000-3000 times, 50% dichlorvos EC 1000, the control effect could reach 95%.

Trichlorfon, dimethoate and dichlorvos are commonly used.