Hatching and survival of Ist and 2nd instars of the Japanese beetle (JB), Popillia japonica Newman, and European chafer (EC), Rhizotrogus majalis (Razoumowsky), was determined in the laboratory in soil at pH levels of 4.6, 5.9, 6.7, and 7.6 at 20°; 25°; and 30°C. Optimum temperature for JB larvae was 25°–30°C. There was no significant difference in survival at any pH except the slightly diminished survival at pH 5.9 at the 95% 2nd instar period. Optimum temperature for EC larvae was 25°C. There was no significant difference in survival at any pH at the 95% 1st instar period and a significantly lower survival at pH 4.6 and 5.9 at the 95% 2nd-instar period. Optimum pH for both species appears to be between 6 and 7, but there is no appreciable reduction in population at pH extremes in normal summer temperature conditions. Since most turfgrasses grow best at soil pH range of 5.5 to 7.0, with severe restrictions in growth and development outside this range, manipulation of soil pHs of turfgrasses does not appear to be a practical method of reducing JB or EC grub populations.