St. Augustinegrass, Stenotaphrum secundatum (Walt.) Kuntze, is used as lawn grass throughout the southern United States for its wide adaptation to varying environmental conditions. The southern chinch bug, Blissus insularis Barber, is the plant's most damaging insect pest. Host plant resistance of St. Augustinegrass to southern chinch bugs has been determined in numerous studies using various techniques. However, temperature has been shown to affect plant resistance to insects; this has not been determined for St. Augustinegrass resistance to southern chinch bugs. In our study, 4 varieties were tested for resistance to adult chinch bugs at 5 temperatures. These varieties were Floratam (susceptible), Captiva (resistant), NUF-216 (resistant), and FX-10 (resistant). The temperatures were 15°, 20°, 25°, 30° and 35°C, and adults were held 7 days at each temperature. Analysis of mean mortalities showed cooler temperatures reduced the ability of LSD tests to statistically determine which varieties were resistant compared with the susceptible variety Floratam. Linear regression analysis showed that mortality was not significantly correlated with temperature in Floratam. In contrast all 3 resistant varieties showed significant positive correlations of mortality versus temperature. These correlation data are consistent with LSD analysis which showed that higher temperatures were better than lower temperatures for discerning St. Augustinegrass resistance to southern chinch bugs held for 7 days.