Insectes Sociaux

, Volume 56, Issue 4, pp 367–373

Effect of soil humidity on the survival of Solenopsis invicta Buren workers

Research Article

DOI: 10.1007/s00040-009-0032-2

Cite this article as:
Xu, Y.J., Zeng, L., Lu, Y.Y. et al. Insect. Soc. (2009) 56: 367. doi:10.1007/s00040-009-0032-2


The effect of soil humidity on the survival of Solenopsis invicta (Buren) workers was evaluated in this study. The study showed that the relative soil water (RSW) content inside the mound contained less variation than the surrounding soil. At a depth of 5 cm underground, the RSW was 7.6% in the mound, while it was 29% in the surrounding soil. At a depth of 20 cm underground, the RSW was 99% in the surrounding soil, while in the mound, the RSW did not reach 98% until it was 45-cm deep. The soil humidity affected the survival rate of S. invicta. For workers, the survival rate decreased when they were exposed to a higher RSW. The spring population had a higher tolerance to a high RSW than the autumn population, while the drought tolerance was the opposite. In extreme RSW, the longer that S. invicta was exposed, the lower their survival rate. The drought tolerance of the fire ant workers could be improved if they were pre-exposed to a low non-lethal RSW for a short period of time. The water content of the workers changed after acclimation to humidity. After a low RSW treatment, the water content of the acclimated workers was higher than the control workers. This suggests that this species is able to maintain a certain water content after acclimation, and that the water content of workers increases in accordance with the RSW.


Solenopsis invictaSoil humidityAdaptation

Copyright information

© Birkhäuser Verlag, Basel/Switzerland 2009

Authors and Affiliations

  1. 1.Red Imported Fire Ant Research Centre and Entomology DepartmentSouth China Agricultural UniversityGuangzhouChina