Damage and Control Methods of Spider Mites on Chinese Cymbidiums

Spider mites are phytophagous, living on the stems and leaves of plants, and are the main pest mites of crops. The life cycle of a spider mite is mainly divided into five stages: egg, larva, protonymph, deutonymph, and adult. Eggs are spherical, transparent, with a crystalline luster, and are scattered on the leaf surface. Newly hatched mites are tiny; the larva has three pairs of legs, and the nymph has four pairs of legs; the reproductive organs of both the larva and the nymph are not yet fully developed. The adult mite has four pairs of legs and mature reproductive organs, and its body is about 0.3-0.5 mm long. Spider mites have strong reproductive capacity and grow and develop rapidly; in summer, completing one generation takes only about a week, and when food is abundant, the density can rapidly increase dozens of times over within two or three weeks. Adult mites spin silk webs on the leaves; when the density is high, the mites not only attach to the leaves but also climb on the silk webs, and crawling spread combined with drifting in the wind causes the damage to spread rapidly to other plants. Adult mites as well as larvae and nymphs all have piercing-sucking mouthparts, resting on the leaves of plants and piercing and sucking the internal nutrients, causing the leaves to show many grayish-white spots, with the leaf surface crinkled and uneven, or even causing the leaves to turn yellowish-brown, dry up, and fall off due to excessive feeding. A dry environment is favorable for the survival and reproduction of spider mites, so they are extremely common in dry, rainless seasons or in greenhouses. The animals that cause damage to flower crops are mainly insects, and also some mites. Mites and insects both belong to the arthropods, share many common characteristics, are similar in appearance and feeding habits, and often occur mixed together in the same place, making them easy to confuse. But in fact insects and mites belong respectively to the Insecta and Arachnida within the arthropods. Their detailed body structures are not entirely the same, their ecological habits also differ, and there are differences in control methods or the types of pesticides used, so they must first be correctly distinguished. The more common mites on flower crops include spider mites, false spider mites, root mites, and thread-footed mites, and their locations, living habits, or the damage they cause to plants all differ. Chen Mingzhao