【Author: Lao Dao Network, Ming Xiaoling】
Twill nocturnal moth larvae hide in the shade during the day and bite young heart leaves at night, especially the young plants planted with test tube seedlings, leaving the leaves incomplete and even eating the heart leaves. During the day, he often fled and disappeared.
First, life habits
imago
Adults of the twill moth can feather throughout the day, with the most abundant from 6 to 9 p.m. After feathering, it lurks in the lower part of the crop, dead leaves or soil gaps during the day, and goes out at night to eat nectar as a supplement to nutrition, and then it can be laid at the end of the egg, and those who do not feed can only lay a few grains. The first stage of spawning is 1 to 3 days, but a few adults can lay eggs within a few hours after feathering. The eggs are mostly laid on tall, dense, dense green marginal crops, mostly at the bifurcation of leaf veins on the back of the leaves in the middle of the plant. Each female can lay 8 to 17 eggs, about 1000 to 2 000 eggs, up to 3 000 grains. Adult insects have strong flight power, and can fly short distances after being frightened, and can fly tens of meters at a time, up to more than 10 meters. Adult insects are very aggressive towards black light, and also have a certain tendency to branches and sweet and sour things that have a fragrant smell. Eggs are laid on tall, dense or dense green plants, with more eggs in the middle, fewer tops and bases, and the egg site is mainly in the middle of the tobacco plant at the tip of the leaf tip on the back of the leaf, and there are not many eggs on the front of the leaf, petiole and stem.
Eggs: Egg development calendar, about 7 days at 22 °C, about 2.5 days at 28 °C.
larvae
Larvae are the most harmful in the morning and evening on sunny days, often hiding in the lower part of the crop or other hidden places at noon, and can be harmful all day on cloudy days. The incubated larvae are infested in clusters, nibbling on the leaf flesh and leaving the epidermis, which is transparent in the window screen, and also has the habit of spitting silk sagging and drifting with the wind; the larvae over 3 years old have obvious suspended death; the food intake of 4-year-old larvae has increased sharply, accounting for more than 90% of the total food intake of the whole larval stage, and there is a habit of migrating in groups when the food is insufficient. The larval development calendar is about 27 days at 21 °C, about 17 days at 26 °C, and about 12.5 days at 30 °C. Mature larvae enter the soil as a pupal chamber, the depth of soil is generally 1 to 3 cm, and can pupate under dead leaves when the soil is compacted.
chrysalis
Pupal development calendar, about 9 days at 28 to 30 °C, and about 13 days at 23 to 27 °C. The twill moth has weak cold resistance and can hardly survive under long-term low temperature conditions of about 0 °C.
Second, harmful symptoms
The larvae mainly eat leaves, but also bite the young stems and petioles, and when they occur, they often eat the leaves and young stems, causing serious losses.
Third, prevention and control methods
Agricultural control
This insect is easier to kill, and the general insecticides such as methamidophos, dichlorides, water amine thion, etc. can be killed by spraying the plant in the evening.
Plough the vacant field in time and eradicate the weeds on the edge of the field. At the peak of larval pupae, the pupae are cultivated in combination with agricultural operations to reduce the population base of insects in the field. During the pupal stage of the twill moth, combined with drought resistance irrigation, most of the pupae can be drowned and the cardinality can be reduced. From the peak spawning period to the initial incubation period of the twill moth, the eggs are manually removed and the hatching larvae are used as harmful leaves, and they are taken out of the field for centralized destruction. Rationally arrange the planting stubble to avoid continuous crop cropping of the twill moth host crop. Where conditions permit, it can be rotated with rice.
Physical control
In the adult period, black light lamps and sweet and sour liquor are used to trap adult insects.
Pharmaceutical reference
2.5% High Potency Cypermethrin Water Emulsion (Moderate Toxicity) Use 40-50 ml/acre spray
5% methylvin perchlorofluoride emulsion (moderately toxic) use 8-12 g/mu spray
3% mevinpyridine microemulsion (low toxicity) use 40-50 g/mu spray
4% methylwid folamide microemulsion (low toxicity) use 9-17 ml/mu spray
3.2% Methyl vitamin salt cyanide microemulsion (moderately toxic) use 40-60 ml/mu spray