Citrus red spider, also known as citrus full-clawed mite. It is a common pest and one of the main pests currently occurring in citrus. How to effectively control red spiders is the key to good citrus quality.
First, the morphological characteristics of red spiders
Egg: slightly flattened spherical, initially orange-red and then bright red, about 0.12-0.14 mm in diameter, with an upright stalk in the center, with 11-12 filaments at the end of the stalk, protruding in all directions.
Juvenile mites: the shape and color are similar to those of mites, and the size is small.
Adult mites: female adult mites are oval in size, hemispherical in shape, about 0.32-0.41 mm long, with nodular protrusions on the back, parasitic white bristles on the upper body, dark red to dark red, 4 pairs of feet, yellow and white; male adult mites are bright red, slender, significantly smaller than female adult mites, wedge-shaped.
Second, the life habits of red spiders
Citrus red spiders overwinter in eggs, in orange leaves, in the back, curly leaves, branches, bud cracks or dead branches of fallen leaves. Red spiders are more reproductive, able to reproduce up to 30-50 grains in a lifetime, and then reproduce for generations. The reproduction of red spiders is affected by temperature and rainfall, and the average temperature is more likely to occur at 25 °C. There are two ways of reproduction of citrus red spiders, generally hermaphroditic reproduction, but there are also parthenogenesis. Citrus red spiders like young leaves and light, so the outer periphery of the canopy, the middle and upper parts occur more, the sunny slopes, poor soil citrus orchards occur earlier, citrus seedlings and young trees due to more shoots, strong sunshine, few natural enemies and heavy victims.
Third, harmful citrus symptoms
The red spider pierces the leaves, branches and fruit epidermis through the sucking mouthpiece, sucking up the sap and chlorophyll. The sap of the leaves is sucked, causing the affected leaves to lose their luster, appearing green spots, and the heavily damaged leaves fall off in gray, affecting the flowering and fruit of the plant. It has a greater impact on the tree potential and yield of citrus trees.
Fourth, prevention and control measures
Agricultural Control:
(1) Strengthen the management of water and fertilizer in orchards. The first step is to strengthen the resistance of fruit trees to citrus red spiders, and this is achieved by applying fertilizer. Secondly, there should be a reasonable plan for the water supply and drainage of the orchard, and a good water supply and drainage system can promote the growth and development of fruit trees.
(2) Improve the ecological environment of orchards. The number of natural enemies largely controls the number of citrus red spiders. Therefore, the number of natural enemies of citrus red spiders in the orchard should be reasonably controlled, of course, there is no other impact on the orchard itself, and it cannot endanger the growth of the orchard. In addition, we must pay attention to the balanced development of the ecological environment of the orchard, and it is very necessary to properly plant some other plants and maintain the ecological environment.
(3) Do a good job in winter pruning and clearing the garden. In winter, long branches, diseased insect branches, and shaded branches are pruned, and the garden is cleared with stone sulfur compound or motor oil emulsion.
Agent Selection:
Spironate, alkynate, daphalone, phentermine, triazoltin (do not use before spring buds to flower), methotrexate, da mite, avermectin. In the winter garden, you can use stone sulfur spray or brush tree trunks, mineral oil, Avi mineral oil.