How does the kale armyworm pest in burdock come about? What are the hazards?

It mainly harms cruciferous vegetables such as cabbage and cabbage, cucumbers, beans, solanaceae vegetables, sugar beets, etc. Spodoptera exigua is swarming, wild, and gluttonous, and the super-hatched larvae are concentrated on the back of the leaf to eat, gnaw on the mesophyll, and the residual epidermis on the leaf is in the shape of a dense "small skylight". When the larvae are slightly larger, they will use the leaves as holes or lack of food, and then spread out.

The occurrence of Spodoptera exigua tends to occur intermittently in the middle of the decade, and when the temperature and humidity are suitable in winter and early spring, the emergence period is early and relatively neat, and it is prone to outbreak disaster years. Specifically, the average temperature of the day is 18 25 and the relative humidity is 70 80%. High temperature, drought or high temperature and humidity are not conducive to its development.

So summer is a clear low tide. An important point that differs from other pests is that adults need to be supplemented with nutrients. In the adult stage, if there is sufficient honey and dew near the fewing, or if there are a large number of flowering plants after the featherement, it may cause a large occurrence.

It is mainly to the larvae to harm the leaves of crops, the larvae at the beginning of hatching are gathered together on the back of the leaves, do not move during the day, eat the leaves at night, and remain under the epidermis, to the older (after the 4th instar), lurking under the leaves during the day, cabbage, the surface or in the soil around the roots, come out at night to live, form gluttony.

The temperature of the cabbage growing environment is 18-25 , and the relative humidity is 70-80%, which is more conducive to the development of Spodoptera exigua. Generally speaking, the environmental conditions of high temperature and drought or high temperature and humidity are not conducive to the growth and development of Spodoptera exigua. When Spodoptera exigua is an adult, and the plant just blooms and bears fruit, it is easy to cause a large number of Spodoptera exigua diseases.

The larvae of Spodoptera exigua mainly eat the leaves of cabbage crops, and in severe cases, they gnaw away the mesophyll, leaving only the veins and petioles.

Spodoptera exigua pests: Spodoptera exigua eats miscellaneous and can harm more than 120 species of plants in 45 families, such as cabbage, cabbage, rape, radish and spinach of the cruciferous family, green peppers, tomatoes, eggplants, potatoes and other crops of the Solanaceae family.

But it is mainly cabbage and cabbage. The first hatched larvae gather the back of the leaves of vegetables to feed on the mesophyll, after the 3rd instar, the leaves are eaten into notches or holes, and after the 4th instar, they are scattered as a pest, feeding day and night, the 6th instar larvae are latent in the rhizosphere soil during the day, and the unearthed at night is a pest, and the older larvae can burrow into the leaf balls such as cabbage and cabbage, which seriously affects the quality and yield of vegetables.