Population Variability and Developmental Time Studies of Cotesia flavipes Cameron (Hymenoptera:Braconidae) Reared on Different Populations of Chilo partellus Swinhoe (Lepidoptera: Crambidae)

Abstract

Variability of two populations of Cotesia flavipes and Chilo partellus was studied for reproductive success and developmental time under laboratory conditions. Fourth instar larvae of two populations of C. partellus (Ziway and Melkasa) were exposed to a day old mated adult female of two populations of C. flavipes (Ziway and Melkasa) to study the variability in reproductive success. The developmental time of the two geographical populations of C. flavipes reared on C. partellus obtained from the two different locations was also studied under four temperatures (20°C, 25°C, 28°C and 30°C). The experiments were designed in a complete randomized design. When both the parasitoid and the host were from the same location, the number of dead larvae inside the host and dead cocoons were significantly lower (p<0.0.5) and the total progeny was significantly higher than when the parasitoid and the hosts were from different locations. However, percent of female progeny was not significantly affected irrespective of the origin of the parasitoid and the host population. The developmental time decreased as the temperature increased from 20°C to 30°C. The significance of population variation in relation to biological control is discussed.

Keywords: Cotesia flavipes; Chilo partellus; Melkasa population; population interaction; Ziway population.

Ethiopian Journal of Biological Sciences Vol. 5 (2) 2006: pp. 177-188