Cold-storage of stink bugs' eggs for rearing oophagous parasitoids.

CINGOLANI, M.F.; GRECO, N.M.; LILJESTHRÖM, G.G.

JOURNAL OF AGRICULTURAL SCIENCE AND TECHNOLOGY (JAST)

TARBIAT MODARES UNIV

Año: 2015 vol. 17 p. 1507 - 1516

1680-7073

ABSTRACT The stink bug Piezodorus guildinii (Hemiptera: Pentatomidae) is an important soybean pest, and egg parasitoids are their main natural enemies. The most common parasitoid of P. guildinii is Telenomus podisi (Hymenoptera: Platygastridae). An important difficulty in implementing augmentative biological control is to obtain large numbers of control agents of appropriate quality, at the time they are required. Rearing T. podisi is constrained by hosts´ quality, which deteriorates after few generations in laboratory. Cold-stored host eggs utilization could be a useful tool for solving this problem. The objective was to evaluate the quality of P. guildinii eggs cold-stored for different periods, on the performance of parental and F1 generation of T. podisi. Parasitism of the parental generation on frozen (-18°C) P. guildinii eggs was significantly lower than that observed on fresh (not frozen) eggs, even for the shorter storage period (one month). Emergence of F1 was also lower from frozen eggs than from fresh ones. Male proportion and preimaginal development time of F1 increased with freezing period. However, parasitism proportion caused by adults of F1, and emergence, male proportion and preimaginal development time of F2 were not affected. Although the performance of T. podisi on frozen P. guildinii eggs was significantly lower than on fresh ones, host eggs storage for up to two months allows obtaining a parasitism rate of 40% with a high emergence rate. This could be helpful enough to maintain mass rearings, mainly during the host hibernation period, and to enhance field parasitism when host is scarce.