The juvenile cutworm, Porbhyrinia parva (Hubner), also known as jujube, Zaohuaxin, etc., belongs to Lepidoptera and Noctuidae. In Gansu, Hebei, Henan, Shandong, Zhejiang date areas, some years are very harmful. Disposable Nonwoven 3Ply Face Mask Child Disposable Facemask,,Civilian Protection Personal Health Face Mask,Disposable Nonwoven 3Ply Face Mask Dongguan Keyutai Mask Co., Ltd. , https://www.maskkytai.com
Damage characteristics? Larvae take jujube flowers and dates. In the flowering period of jujube, larvae make silk flowers and drill in the inflorescences to take in stamens and honey trays. Only the flower discs and flower buds are left in the damaged flowers. In severe cases, all the stamens on the jujube hanging are often eaten so that they cannot produce results. During the growth period of jujube fruit, larvae can be tangled and wounded with fruit stalks and eaten with dates. The damaged fruit gradually dries, but does not fall off.
Morphological characteristics adults: body length of about 5 mm, wings about 15 mm, body light brown, dark brown front wings, there are three white curved stripes, there is a dark spot near the top corner. It is a pale gray small moth.
Egg: skull-shaped, radial pattern. White is transparent and becomes pale red before hatching.
Larvae: Mature larvae are 10 to 14 mm in length, yellowish green and similar in color to date flowers. On the back of the chest and abdomen there are pairs of diamond-like purple lines (a few larvae do not have this feature). Each section grows thinly. Gastropod 3 pairs.
蛹: 6 to 7 mm long, obese. At the time of initial phlegm, the head and thorax were bright green and the back and abdomen were dark yellowish green. Feathers before the whole tan.
Habits of life?? Zizyphus japonicus in Lanzhou area occurs one generation a year, in Hebei, Shandong, Zhejiang and other places a year 2 generations. The wintering of the bark cracks, tree holes, moss, etc. In the middle and early May of the following year, the adult began to emerge, and in the later half of the year, it was the emergence period. Adults have phototaxis. The eggs are sparsely scattered between the peduncles or the base of the petiole, and each female lays about 100 eggs. The first generation of larvae began to hatch in late May. After hatching, the larvae return to the flower bushes to injure the jujube flowers. When they are large, they can spin silk to connect a cluster of flower decorations and harm them until the flower clusters turn yellow and wither, and then continue to feed on the young fruit. The larvae are inactive and slow in action. Some larvae start to droop after they start to frighten. The first generation of larvae matured in early June and ended in mid-July. Some of this generation of storks are no longer feathered and overwinter, resulting in 1 year and 1 generation; the other part begins to emerge in late June and ends in late July, resulting in the second generation. The second generation of larvae began to appear in early July. This generation of larvae eat more jujube fruit, and there is a conversion of fruit to the habits, generally 1 larvae can damage 4 to 6 jujube fruit. From late July to mid-August, the larvae of this generation have matured and sloughed over the winter. In the later period, when there is no flower, when the fruit is edible, the spun silk binds the young leaves of the branches and hides in them. From late July to mid-August, this generation of larvae begins to mature and enter the cracks in the bark or in the gaps between the branches of the trunk.
Control methods
1, dormant period scrape jujube rough cracked skin, eliminate the overwintering.
2. Spray larvae to kill larvae in late May. Available agents: 50% trichlorfon 50 times, 50% dichlorvos 80O times, 50% carnitane 1O00 times, or 50% malathion 1000 times. Or 2.5% swab emulsion 4000 times. Bacillus thuringiensis can also be sprayed with 50 million/ml of broth.