Maisui Ye

The scientific name Apameasordens (Hufnagel) belongs to Lepidoptera, Noctuidae. Alias wheat spike worm. Distributed in Inner Mongolia, Gansu, Qinghai and other provinces.

Host @, barley, highland barley, wheatgrass, horse lotus grass and so on.

The damage characteristics of the newly hatched larvae first feed on the flower organ and ovary of the ear, and individually feed on the tender surface of the inner wall of the glume, and then transfer to the damage. After the 3rd instar, the larvae latent in the grain, and after the 4th instar, the larvae transfer to the flag leaf to spin silk and connect the leaf margin to form a tube, and look for wheat ears to feed after sunset.

The morphological characteristics of the adult are as follows: body length 16mm, wingspan 42mm, all grayish brown. The front wing has obvious black base sword lines, swallows below the midvein, ring pattern, reniform pattern silver gray, edge black; base line light gray double line, sub-baseline, end line light gray double line, serrated; sub-terminal line wavy light gray; the outer edge of the front wing has 7 black spots, the margin is dense; the hind wing is light yellowish brown. Ovoid, 0.61-0.68mm in diameter, with patterned egg surface. The body length of the last instar larvae is about 33mm, the head has a light brownish yellow "eight" pattern, and the lateral cranial area has a light brown reticular pattern. The topline and subtopline on the anterior chest scutellum and gluteal plate were divided into 4 light brown stripes, the insect body was grayish yellow, the back was grayish brown, and the ventral surface was grayish white. The pupa is 18-21.5mm long, yellowish brown or brown.

The living habits are one generation a year, overwintering with mature larvae in the field or under the topsoil of the ridge and under the pier of Achnatherum splendens. The overwintering larvae were stung in April of the following year, and the larvae pupated from the end of April to the middle of May. The pre-pupal period was 6ml for 11 days, and the pupal period was 4455 days. The adults Eclosion from June to July, enter the peak period from the middle of June to the first ten days of July, hide under wheat plants or grass during the day, fly out at dusk and feed on wheat pollen or oil. Six days after mating, the eggs laid on the inside of the first spikelet or on the ovary of the first spikelet of wheat generally formed into blocks, and the number of grains per piece varied from 38 to 38. The number of eggs laid by the female moth reached 740, the egg period was about 13 days, and the larvae molted 6 times, a total of 7 instars, with a duration of 8 and 9 months. The damage period of the larvae is 66 minutes and 5 days. The newly hatched larvae first eat the flower organs and ovaries of the ear, and then transfer them. The mature larvae have the habit of feeding every other day, and the 6th and 7th instar larvae grow up. During the day, the larvae transferred from the wheat leaves to the weeds to embroider the leaves, and some lurked in the topsoil or soil crevices. In the middle of September, the larvae began to overwinter in the loose soil in the rhizosphere of wheat stubble.

Control methods (1) making use of the phototaxis of adults, black light was installed to trap and kill adults from the first ten days of June to the end of July. (2) spray 80% dichlorvos EC 1000-1500 times or 90% crystal trichlorfon 900-1000 times before the 4th instar. (3) after 4 years old, the insecticides mentioned above should be sprayed after sunset when they are latent during the day. (4) during wheat harvest, attention should be paid to killing the larvae under the wheat sheaf in order to reduce the population number of overwintering insects. (5) set up the trapping belt. After Eclosion, the adult mainly feeds on rape nectar before mating, and its peak occurs at the flowering stage of a large area of Youlai in the area, and likes to lay eggs on the spikes of precocious crops such as green trees and wheat. The mixed green trees and early maturing wheat in the same wheat field lay the most eggs and suffer the most. According to this habit, planting nursery trees and early-maturing wheat around the wheat field and in the middle of the field can induce adults to lay eggs. At the same time, because the larvae of Spodoptera litura are harmful spike grains before the 3rd instar, and the larvae transfer and feed after the 4th instar, the trapping belt will be removed or sprayed in time before the larvae are transferred after oviposition, which will greatly reduce the source of worms and achieve the purpose of protecting field wheat from damage.