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The effect of five constant temperatures (16, 22, 26, 31 and 36 "C) on biological (survival and duration of developmental stages, fecundity and longevity of females, sex-ratio) and demographic parameters (Roy G, r, and A) of the two main phytophagous mites that attack cassava in Africa, Mononychellus progresivus Doreste and Oligonychus gossypii (Zacher), was studied in the laboratory. Experiments were performed simultaneously on the two mite species reared on the same cassava variety (1M20) under controlled conditions: 70 zt 10% r.h. and 12L:12D. The lower thermal threshold was 13 "C for M. progresivus and 11 OC for O. gossypii. Both species developed in the range from 22 to 36 OC. The shortest development time was obtained at 3 1 "C for both species; it was 7.2 days for M. progresivus and 8.2 days for O. gossypii. Maximum fecundity of both species was recorded at 26 "C with 42.1 eggs for M. progresivus and 36.3 eggs for O. gossypii The highest intrinsic rate of increase (r,) was obtained at 3 1 "C for both species with 0.289 and 0.214 for M. progresivus and O. gossypii, respectively.

An artificial diet used in the laboratory in Kenya for rearing larvae of the sorghum pest Atherigona soccata Rond. is described. The main ingredients of the diet are shredded tissue paper (50 g), brewers' yeast (20 g), vitamin-free casein (15 g), methyl 4-hydroxybenzoate (0.75 g) and water (200 ml). Two generations of the fly were successfully reared on the diet