INTRINSIC RATE OF INCREASE OF LYSIPHLEBUS TESTACEIPES CRESSON (HYM, BRACONIDAE), A PARASITOID OF APHIS-GOSSYPII GLOVER (HEM, APHIDIDAE) AT DIFFERENT TEMPERATURES

Lysiphlebus testaceipes Cresson is one of the candidates for use in a programme for biological control of cotton aphid, Aphis gossypii Glove r. Longevity, reproduction, development, and intrinsic rate of increas e of L. testaceipes were determined in the laboratory at two different temperatures with cotton aphids as host. The average life-time fecund ity of one parasitoid was 128.2 eggs at 20 degrees C and 180.0 eggs at 25 degrees C. Immature mortality was 9.5 and 29.6% at 20 and 25 degre es C respectively. Development from egg to female adult was completed in 12.9 days at 20 degrees C and 9.5 days at 25 degrees C. The lifespa n of the females was very short (2.7 and 2.6 days at 20 and 25 degrees C respectively). At 20 degrees C the r(m) value of L. testaceipes was slightly lower than for cotton aphid. At 25 degrees C the r(m) values of L. testaceipes and A. gossypii were equal. Lysiphlebus testaceipes might be a suitable natural enemy although r(m) values are probably t oo low to be able to overtake an established aphid population.