Disease and insect pest of national orchid-- leaf mite

Leaf mites are herbivorous, live in plant stems and leaves, and are the main harmful mites to crops.

The life of spider mites can be divided into five stages: egg, larval mite, pre-nymph, post-nymph and adult mite. Ovoid, transparent, glossy, scattered on the surface of leaves. The newly hatched mites are minute, the young mites have three pairs of feet, the nymph mites have four pairs of feet, and the genitals of young mites and nymph mites are not fully developed. Adult mites have four pairs of feet and mature reproductive organs. The body length of adult mites is about 0.3 × 0.5 mm.

Spider mites have strong fecundity and rapid growth and development. it takes only about a week to complete a generation in summer, and the density can multiply to more than tens of times in two or three weeks when food is sufficient. Adult mites will spin silk and form a net on the leaves, and when the density is high, the mites not only attach to the leaves, but also climb on the bead net, crawling and spreading with the wind, so that the damage quickly spreads to other plants.

Adult mites, young mites and nymph mites are piercing mouthparts, which rest in the leaves of the plant and suck internal nutrients, so that the leaves show many gray-white spots, the leaf surface is wrinkled and uneven, or even make the leaves turn yellowish brown and dry and fall off due to excessive intake. Dry environment is conducive to the survival and reproduction of spider mites, so it is very common in the dry season or in the greenhouse.

The animals harmful to flower crops are mainly insects, and there are also some mites. Mites and insects belong to arthropods, both of which have many common characteristics, and their appearance is similar to their feeding habits, and they are often mixed and exist in the same place, which is easy to be confused. But in fact, insects and mites belong to Insecta and Arac hnida of arthropods. The detailed structure of the body is different, the ecological habits are also different, and there are differences in control methods or types of pesticides, so it is necessary to make a correct distinction.

The common mites in flower crops are spider mites, pseudo-spider mites, root mites and fine mites, which are different in their location, living habits or damage to plants.

Chen Mingzhao