POPULATION PARAMETERS OF 3 PARASITOIDS (H YMENOPTERA, SCELIONIDAE, ENCYRTIDAE) HOSTED BY THE PREDATOR PODISUS-NIGRISPINUS (HEMIPTERA, PENTATOMIDAE)

The reproductive parameters of Telenomus podisi, Trissolcus brachymena e (Hymenoptera: Scelionidae) and Ooencyrtus sp. (Hymenoptera: Encyrtid ae) were studied for three generations on their natural host Podisus n igrispinus (Dallas, 1851) (Hemiptera: Pentatomidae). A parasitism rate of 10 eggs/day/species was used under laboratory conditions of 27 +/- 1 degrees C, 60 +/- 10% RH and 14 h of photophase. No significant dif ferences were detected between generations in terms of net reproductiv e rate (R-0), intrinsic rate of natural increase (r(m)), generation ti me (T) and the effect of doubling time on population increase (DT). Ho wever, T. podisi and T. brochymenae had significantly higher R-0 and r (m) values, and lower T and DT values, with r(m) 1.59 and 1.50 times h igher than Ooencyrtus sp., respectively. In addition the former specie s also had shorter egg-adult period, greater longevity of females and reproduction period than the other species. These results confirm the greater reproductive potential of T. podisi and T. brochymenae, which are commonly found parasitizing P. nigrispinus.