Sex-ratio Bias in Natural Polygyne Colonies of the Red Imported Fire Ant, Solenopsis invicta (Hymenoptera: Formicidae)

摘要

After a one-year investigation, it was found that there was a serious male bias phenomenon in natural polygyne colonies of Solenopsis invicta Buren in south China. In the Liuyi Area of South China Agricultural University (SCAU), the Wushan Yuejin Areaof SCAU, Wasteland in Zengcheng, and Banana Park in Zengcheng, the maximum proportions of nests without female pupae were 40%, 40%, 43% and 33% respectively, while the maximum proportions of nests without male pupae were 17%, 17%, 30% and 17% respectively, without female alates 30%, 30%, 40% and 27% respectively, without male alates 20%, 23%, 23% and 20% respectively. A paired T-test was carried out for comparison for the sum of pupae and alates between male and females. The results showed the male sumwas larger than the female, and there were significant differences between them (t=3.37, df— 11, P<0.05). Further, we compared the investment (the gross weight) ratio between male and female alates, and the results showed there was no difference (t=0.49, df=11,P=0.63).