What are the living habits, effects and distribution of the horned gall aphid (Chinese gall aphid)?
The horned gall aphid, also called the gall aphid or Chinese gall aphid, is an insect of the genus Schlechtendalia in the aphid family. In summer it mainly parasitizes plants of the Anacardiaceae family, such as the compound leaf wings or the tender leaflets of Chinese sumac (Rhus chinensis). The leaves wounded by the horned gall aphid develop irregular tumor-like galls called “Chinese gall”, which are water caltrop-shaped. So what are the living habits of the horned gall aphid? What effects does it have?
The Chinese gall formed by the horned gall aphid parasitizing Chinese sumac, also called the horned gall, is a water caltrop-shaped, oval or irregular sac-like body with several irregular horn-like branches or tumor-like protrusions, about 8 cm long and about 5 cm in diameter. The surface is grayish-yellow or yellowish-brown, with grayish-white soft smooth fuzz. The gall wall is about 1-2 mm thick. The texture is hard and brittle, and the gall contains numerous grayish powdery aphid corpses and their waxy secretions. It has a distinctive odor and an astringent taste.
Living habits of the horned gall aphid
The winter host of the horned gall aphid is Plagiomnium acutum and Plagiomnium, which grow in shady and damp environments. Every autumn, winged individuals fly to the moss, produce young aphids, and secrete a white waxy substance that surrounds their bodies. In the following spring (March-April), the overwintering aphids emerge as winged individuals, fly away from the moss, and migrate to Chinese sumac to live. They produce female aphids and male aphids on the leaf buds of Chinese sumac. They shelter in cracks in the trunk. After several molts, the sexual aphids develop into adults and then mate; after mating the males soon die, and the females lay eggs, which hatch into wingless parthenogenetic female aphids called fundatrices. The fundatrix invades the young tender tissues of the tree, sucks the sap, and at the same time secretes saliva that stimulates the plant tissues at the feeding site, causing the plant cells to proliferate continuously, gradually enclosing the horned gall aphid inside to form a gall (the rudiment of Chinese gall). The gall aphid continues to feed inside the gall and reproduces offspring by parthenogenesis. From August to October, the gall continues to enlarge, and the last generation of wingless female aphids inside the gall produces winged individuals (autumn migrant aphids). After the gall bursts open at the horned tip, the aphids escape, fly away from Chinese sumac, and migrate to the host bryophytes to feed on the tender parts or roots. They reproduce and overwinter there, and at the same time secrete a white waxy substance on the body surface that surrounds the body in a spherical shape, defending against cold so they can overwinter safely, until the following spring (March-April) when they emerge as winged individuals, fly away from the moss, and migrate again to Chinese sumac to reproduce.
The horned gall aphid is fairly widely distributed, and is also found in Guizhou, Yunnan, Liaoning, Jilin, Henan, Guangxi and Guangdong. It is mainly produced in Hubei, Hunan, Sichuan, Guizhou, Shaanxi and other places.
Effects of the horned gall aphid
The horned gall aphid has functions such as astringing and stopping bleeding, astringing the lungs and relieving cough, astringing the intestines and stopping diarrhea, reducing sweating, and detoxifying. It mainly treats cough due to lung deficiency, chronic diarrhea and rectal prolapse, excessive sweating, bloody stool, coughing blood, spermatorrhea, enuresis, sores and ulcers, and poisoning by heavy metal salts and alkaloids; for external use it treats scalds and burns, rectal prolapse, hemorrhoids, cervical erosion, lymph node tuberculosis, stomatitis, gingivitis and so on. The horned gall aphid is also an important raw material and reagent for industries such as dyes, leather making, chemicals, petroleum and smelting.