Population dynamics of an acridid grasshopper, Diabolocatantops pinguis, were monitored for 3 y, from October 1990 to September 1993, at two sites in Tamil Nadu, a southern state of India. The fluctuations in the population at the two sites were related to abiotic factors, such as maximum and minimum temperatures, rainfall and relative humidity, using Kendall's correlation coefficient test. We tested a hypothesis that the effects of each abiotic factor may be varying, i.e., from immediate to delayed. These analyses involved several correlation coefficient tests. Hence we also performed a sequential Bonferroni test to eliminate levels of significance that emerged due to sheer chance. Maximum temperature imposed a significant delayed negative effect on the population of this species that was prolonged 2–3 mo. Minimum temperature had a significant negative lag effect of about 2 mo. at Tambaram. Rainfall had a significant positive effect on the population immediately at Tambaram or with a lag (∼ 1 mo.) at Chinglepet. Relative humidity had a significant positive lag effect of about a month at Chinglepet only. The trends in the immediate effects of abiotic factors on the population of D. pinguis in both the study sites were comparable.