Scientific name：Tetranychus kanzawai Kishida
Perching mainly on the back of the leaves, not the front side. Due to the limited range of motion, several leafhoppers can been seen to cluster on the surface of a small area of the leaf, but not on the entire leaf. Because of its suction, it causes partial gray spots on the leaves. When the density is high, most of the whole leaf has gray spots, or even becomes dry and withering. The orchids with relatively thin leaves, such as Cymbidium, seem to be more affected by leafhoppers than orchids with thick leaves, such as Cattleya and Dendrobium.
The larvae are rufous-brown or yellow-brownish, and the male adult with several black spots on the backside of its broad oval body. Their bodies are translucent, and then turned to light brown.
Scientific name：Tenuipalpus pacificus Baker
They have strong reproductive ability, but its growth and development will take longer compared to leafhoppers. In a high-temperature and dry environment, extremely high density of insects can still be formed on the leaves after a period of time. The adults do not have the ability to produce silk. Gathering on the back of the leaf near the middle ribs or branch ribs or branch veins for feeding. The leaves will suffer the decolorization and browning. The food marks extend from the middle ribs to the petiole, the spots may spread along the leaf veins to the whole leaf, causing severe defoliation, plant dwarfing, and poor growth performance.
Adults are oranges or yellow-orange, with irregular black spots on the back. The body is flat, about 0.2-0.3 mm long, and the body is clearly divided about the center, dividing the body into the front and rear halves. The front half is blunt, the back half is more pointed, and the end of the abdomen is narrowing. When at rest, the four pairs of feet are straight out. Eggs are red and blunt, oval at both ends. Larvae are orange-red, three pairs of feet, and oval.
Photos for affected plants