Summer is hot and rainy, which is a period of serious pest outbreaks, and in June, improperly managed loquat orchards will continue to occur this year if yellow caterpillar infestations have occurred in previous years.
Yellow caterpillar larvae look like yellow caterpillars on the surface, and the adult wings are grayish white with silver light. The yellow caterpillar host plant is the exception of loquat. The larvae eat the young buds and young leaves of loquat, and when they occur, they also eat the old leaves, the skin of the young stem and the peel, although they only eat the peel, but the appearance of the fruit loses its commodity value, and even the deformity loses its edible value. When the damage is severe, only the leaves of the whole plant are left with veins, resulting in death.
Because the egg production of yellow caterpillars is not as high as that of pests such as ticks and wood lice, some orchard yellow caterpillars are not harmful at the beginning, but fruit farmers do not have special control, resulting in yellow caterpillars passed down from generation to generation, and more insect pests may erupt in the next year.
The current methods for controlling loquat yellow caterpillar are:
1. Remove dead branches, weeds and overwintering insect pupae from the garden in time in winter and spring, and burn them in a concentrated manner. Apply lime in an appropriate amount, scrape the bark and paint white to cut off the wintering host and eliminate the source of wintering insects.
2. Spray the larvae in time to eliminate the larvae and protect the new shoots and new leaves during the peak of each generation. If there is an outbreak during the harvest period, no pesticides are allowed, only agricultural or biological methods.
3, the protection and utilization of natural enemies, loquat yellow caterpillar predators are mainly parasitic bees, such as the vast leg wasp, camel wasp, etc., the high parasitic rate of loquat yellow caterpillar, should be protected and utilized.
4. Use the tool to catch some yellow caterpillar larvae and pupate in the cage with 3 to 4 mm hole yarn, so that the adult and larvae of the yellow caterpillar cannot escape, and the parasitic adults can fly out.
5, control nitrogen fertilizer, increase the application of phosphorus, potassium fertilizer, so that the tree does not apply nitrogen fertilizer; do a good job of drainage and irrigation system, so that the rainy season can drain, drought can be irrigated, young tree gardens in July to August generally do not irrigate, timely loosening of the tree tray.
The loquat yellow caterpillar outbreak also coincided with the outbreak of other insect pests, such as pear heartworms and psyllids, during which fruit farmers controlled loquat trees, which together cleaned up other pests and reduced unnecessary trouble.