Spodoptera litura

DiometacremetaButler belongs to the family Lepidoptera. It belongs to one of the bridge-building insects, which is one of the most important pests to damage edible fungi such as Ganoderma lucidum, Pleurotus ostreatus, Auricularia auricula and so on.

The main damage characteristics are to eat Ganoderma lucidum cap and meat, leaving a curved tunnel at the victim site. And there are notched holes in the fruiting body. Reduce the commodity value of Ganoderma lucidum.

Morphological characteristics

The adult is 11 mm long and has a wingspan of 25-26 mm. The male body is dark purple-brown, and there are thick clusters of scaly hairs on the back of 1-2 segments of head, chest and abdomen. The antennae are filiform, the lower lip is grayish black, curved upward, the basal segment is small, the second segment is large, the third section is small, and its base and end are white. The front wing is purple-black with luster, the base is light black, the base horizontal line is yellow-white outer curve, the middle horizontal line is black, the kidney-shaped grain black inner curve is in the shape of "3", the front end of the outer edge of the front and rear wing is a yellow-brown spot, followed by a row of small white spots, arranged in an arc; the back end of the outer edge of the rear wing fuses into a white curve. The female body is dark brown and the forewings are dark brown.

The egg is 0.5 mm long, 0.8 mm in transverse diameter, round and green. There are more than 40 raised longitudinal ridges on the surface, and more than 20 fine horizontal ridges are connected between the longitudinal ridges.

The larvae have a total of 5 instar larvae, the last instar larvae are 25-30 mm long, the head is dark brown, the abdomen is cylindrical, the internodes constricted obviously, the dorsal midline is dark green, and the back longitudinally scattered white twisted lines. Each segment is of different size, brownish yellow and milky white. There are 3 pairs of abdominal feet in the 5th, 6th and 10th ventral segments, which are listed in the single order of toe hooks.

The pupa is 11-13 mm long and has 2 pairs of short thorns at the end of the abdomen.

The occurrence regularity of Spodoptera litura occurs 5-6 generations a year in the south, mainly overwintering as pupae, usually Eclosion into adults in the middle of April, and the whole generation lasts about one month. The adults had a tendency to sweet and sour and pollen. The female laid eggs on the third day after Eclosion, and laid the most eggs on the fourth and fifth day. The eggs were scattered on the fruiting body and the surface of culture material at night or in the morning. The growth temperature of the insect is 20-30 ℃, the egg stage is 5-6 days, the larval stage is 11-15 days, the pupa stage is 8-12 days, and the adult life span is 3-13 days. The old larvae move slowly and have the habit of hanging as cocoons. The larvae can still move in November, and the mature larvae gradually pupate into the overwintering stage from late October to early November.

Prevention and cure method

The main results are as follows: (1) strengthen the cultivation management, install screen doors and screen windows in the mushroom house, prevent adults from moving in, do a good job in environmental hygiene, and collectively remove the wastes and weeds around the mushroom house, so as to reduce the source of insects.

(2) after the last crop of edible fungi is received, the insect population remaining in the material should be killed in time to reduce insect pests.

(3) the older larvae move slowly and have the habit of hanging cocoons, which can be caught and removed manually to reduce the population density.

(4) Chemical control when a large number of insect pests occur, spray the material surface, cultivation rack and so on with 5000-8000 times of the emulsion or other pyrethroid pesticides after picking mushrooms.

Commonly used agents to quickly kill butyl chloride emulsion.