LABORATORY STUDIES OF THE EFFECT OF TEMPERATURE AND HUMIDITY ON DEVELOPMENT AND FECUNDITY OF PARABEMISIA-MYRICAE (KUWANA) (HOMOPTERA, ALEYRODIDAE)

The effect of six temperatures and three relative humidities on the de velopmental period of immature and the fecundity of Parabemisia myrica e (Kuwana) was studied, separately, in the laboratory. The development al time from egg to adult stage was 79.7; 41.7; 24.4, and 22.0 days at 15, 20, 25, and 30-degrees-C temperatures, respectively. The developm ental time at the fluctuating temperatures of 25/35-degrees-C (12/12 h ) was 24.2 days. With increasing relative humidity at 25-degrees-C con stant temperature, the total developmental time decreased significantl y from 26.7 days at 40 % RH to 20.3 days at 90 % RH. The mortality rat e was lowest at 25-degrees-C and was highest at 30-degrees-C and 25/35 -degrees-C. It was also found that temperatures above 35-degrees-C wer e lethal, since all eggs were killed at 35-degrees-C. At the three rel ative humidities tested, the mortality rate of the egg stage was highe st at 90 % RH (20 %) and about 44 % of the immature stages were killed at 40 % RH. The adult's (female) longevity and the reproduction chang ed with changes in temperature; oviposition rate increased by the incr ease in temperature up to 25-degrees-C then remained at the same level .