Life-table studies on Epidinocarsis lopezi (De Santis) (Hym., Encrytidae), a parasitoid of the cassava mealybug, Phenacoccus manihoti Mat.-Ferr. (Hom., Pseudococcidae).
1989
Loehr B. | Varela A.M. | Santos B.
Life-table studies were conducted on Epidinocarsis lopezi, a South American parasitoid, introduced to control the cassava mealybug in Africa. In a range from 20 to 30 degrees C, optimal temperature for parasitoid development was found to be 30 degrees C with a time span of 8.5 days from egg deposition to host mummification, and 15.4 days for males and 15,9 for females until emergence. At 25 degrees C and above, the development of the males was significantly faster than that of the females. However, males were the first to emerge at all temperatures. Host age had a significant influence on parasitoid development: in ten days old CM (second instar), mean time to adult emergence was 3.7 and 5.1 days longer than in 16 and 22 days old CM, respectively. The differences occurred before the mummification of the host. The lower thermal threshold of the parasitoid was calculated as 14,7 degrees C for males and 14.4 degrees C for females. Both females and males lived longer at 22 degrees C (18.9 and 14.0 days, respectively). At all temperatures, female survival was higher than the one of males. The average number of offspring produced per female was 83.9 at 22 degrees C, at all other temperatures, only between 45.1 (20 degrees C) and 33.3 (30 degrees C) progeny were produced. Females slightly outnumbered males at all temperatures, except at 20 degrees C. E. lopezi feeds on its host and the average daily host consumption increased from 0.8 CM at 20 degrees C to 2.5 at 30 degrees C. The highest intrinsic rate of increase for the wasp was 0.166 at 27 degrees C.
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