Effect of host availability and egg load in Trichogramma platneri Nagarkatti (Hymenoptera: Trichogrammatidae) and its consequences on progeny quality

Experiments were conducted to determine whether Trichogramma platneri Nagarkatti manifested a somatic-gametic trade-off and whether it was affected by host availability and host size. Large wasps produced on Trichoplusia ni Hübner and limited to five or 15 T. ni eggs daily, produced a similar number of progeny as wasps offered hosts from emergence. Similar results were obtained when they were deprived of T. ni eggs for one, three, five, or ten days and then provided with unlimited hosts daily until death. In contrast, small wasps produced from Sitotroga cerealella (Olivier) and deprived of T. ni eggs for one to three days suffered a significant reduction in progeny production. Regardless of size, the egg load of non-ovipositing wasps increased significantly with time and a positive relationship existed between the life span of a female and the length of time she was deprived of hosts.