[Effects of Solenopsis invicta invasion on the diversity of spider communities in a corn field]

By using pitfall trapping and ocular estimation, this paper studied the effects of Solenopsis invicta invasion on the diversity of spider communities in a corn field. A total of 16 spider species belonging to 8 families were recorded. In the plot S. invicta invaded, there were 10 spider species of 6 families, among which, 5 species of 4 families were in pesticide-treated plot, and 11 species of 8 families were in control plot. The spiders were dominated by wandering species, mainly belonging to the families Salticidae and Oxyopidae, and the dominant species were Oxyopex sertatus, Myrmarachne joblotii, and Myrmarachne sp. In the plot S. invicta invaded, the population quantity of S. invicta began to increase steadily from the late whorl stage of corn, with the peak (225 individuals) through the earring stage, but decreased steadily thereafter, with the decrement of the spiders of genus Oxyopex reached 79.2%, while the population quantity of the spiders of genus Myrmarachne had no significant change. With the growth of corn, the species number, diversity index, and evenness index of the spiders in S. invicta-invaded and pesticide-treated plot decreased and the predominant indices increased gradually, while the situation in control plot was in adverse. It was concluded that due to the S. invicta invasion in corn field, the community structure of spiders changed.