APHIS gossypii

Scientific name Schizaphisgraminum (Rondani) Homoptera, Aphididae. All over the country.

Host @ 245 grass, barley, oats, sorghum, rice, dogtail grass, sedge and other gramineous plants.

The damage characteristics of wheat aphids often suck sap inside and outside the positive and negative sides of wheat leaves or the basal leaf sheath, resulting in yellow withering of wheat seedlings or unable to jointing on the soil, and serious wheat plants can not heading normally, which directly affects the yield. in addition, wheat yellow dwarf disease can be transmitted.

The morphological characteristics of wingless parthenogenetic aphids are 2.0mm, oval, light green, dark green in the dorsal midline, light green in the ventral canal and black at the top. The middle chest and abdomen bifurcation has a short handle. The frontal tumor is higher than the middle frontal tumor. The antennae have 6 segments, the total length is more than half of the body, the beak exceeds the middle foot ganglion, and the terminal segment is thick and short, and the length is 6 times of the base width. The ventral canal is long cylindrical, the tail is long and conical, the length is 1.5 times of the base width, and there are 6 long hairs. The body length of winged parthenogenetic aphids is 1.8mm and long ovoid. Green when alive, dark green on the back of the midline. The head and chest are black and the abdomen is light. The tentacles are black with 6 sections, more than half the length of the body. Section 3 of the antennae has 10 small circular secondary sensory circles arranged in a row. Midvein of forewing bifurcate.

The living habits of wheat aphids are similar to those of APHIS gossypii, with an annual age of 20-30 generations, and the specific algebra varies from place to place. Mixed area and early sowing of winter and spring wheat

The dynamics of population growth and decline in winter wheat field: after the autumn seedlings were unearthed, they began to reproduce in the wheat field, and there was a small peak from 3-leaf stage to tillering stage, and overwintered with eggs on the stubble of winter wheat field in early November. The overwintering eggs hatched in the first and middle March of the following year, and after reproducing on winter wheat for several generations, some of them continued to reproduce as wingless female aphids, some produced winged fetal aphids to reproduce and spread in winter wheat fields, some moved to spring wheat in the middle of April, and multiplied in large numbers in the first and middle of May, which appeared the peak period of damage and caused the epidemic of yellow dwarf disease. The development rate of APHIS gossypii was positively correlated with temperature at 10 ℃ and 30 ℃. The survival rate below 7 ℃ was low, the viviparous reproduction was fast at 22 ℃, the growth and development was the fastest at 30 ℃, and 42 ℃ died rapidly. Under suitable conditions, the aphid has strong fecundity and short development period. the population density of the aphid increases rapidly at the jointing and booting stage of wheat, and the number of aphids can reach more than ten thousand aphids per hundred plants.

The control method is the same as that of wheat aphid.