Host discrimination and parasitism rate of trissolcus basalis wollaston (Hymenoptera: scelionidae) parasitizing eggs of nezara viridula (L.) (Heteroptera: Pentatom Midea) in cotton fields in Egypt [electronic resource].

Includes references.

Discrimination of aged host eggs showed that when exposing N. viridula egg masses of I'\ 2nd and 3n.1 days old to females of T. basalis had affected the total developmental period (egg - adult) of the parasitoid. It was 12, 13 and 17 days, respectively with a minimum developmental period of 13.4±1.46 days. Results indicated that I-day old eggs of the host were the most suitable for high parasitism rate (79.16%) and parasitoid emergence (96.49%), and were associated with the shortest developmental period (12 days). Older host eggs decreased both rate of parasitism and parasitoid emergence in addition to prolonged developmental period of the parasitoid immatures. T. basalis is represented as the only natural enemy responsible for control of N. viridula under natural conditions. Rate of parasitism was investigated in three successive years i.e., 2003, 2004 and 2005 in egg masses collected from cotton fields. Percentage of parasitism in egg masses ranged between 33.33% and 77.31 %, while among eggs within each mass it ranged between 73.21 % and 97.59%, and sometimes reached 100% parasitism.

1