Abstract: By the method of bait trapping, this paper studied the relationships b
etween mound size (mound volume and mound surface base area) and captured ergate
 amount of Solenopsis invicta in wasteland and greenbelt. In wasteland, with
 the
 increase of mound size, the amount of captured S. invicta ergates increased
 rap
idly at first, slowed down then, and kept stable at last. When the mound volume
and surface base area were 11634 cm3 and 1308 cm2 respectively, the captured
 ergate amount reached the maximum, being 291 individuals per trap. Similar patt
erns were observed in greenbelt. The increase of captured S. invicta ergate
amou
nt slowed down rapidly when the mound volume was larger than 18089 cm3, and re
ached
the maximum (232 individual per trap) when the mound volume was 25974 cm3. The
 We
ibull equation could better describe the relationships between the mound volume
and mound surface base area and the captured ergate amount of S. invicta.

Key words: Solenopsis invicta, ant mound volume, ant mound surface base area, captured ergate amount, summer fallow, rape, winter wheat, soil moisture.