P. Caballero et al., BIOLOGY OF COTESIA (= APANTELES) TELENGAI (HYMENOPTERA, BRACONIDAE) ON ITS NATURAL HOST AGROTIS-SEGETUM (LEPIDOPTERA, NOCTUIDAE), Biocontrol science and technology, 3(4), 1993, pp. 481-489
The host suitability of Agrotis segetum Denis and Schiff., A. ipsilon
Hufn., Spodoptera littoralis Boisd., S. exigua Hub., Mythimna loreyi D
uponchel and Mamestra oleracea L. for the gregarious braconid Cotesia
(= Apanteles) telengai Tobias was determined under laboratory conditio
ns. The parasitoid only completed its development in larvae of A. sege
tum. The percentage of successfully parasitized larvae and the mean du
ration of C. telengai egg-larval period were inversely related to the
age of the host ol host instar at parasitization. The mean number of p
arasitoids which emerged per parasitized larva was positively correlat
ed with the larval age. The sex ratio was consistently high (ca. eight
males to one female), independent of the host instar parasitized, as
compared to 1:1 as observed frequently in field populations of this wa
sp. The females of C. telengai were active and produced offspring at t
emperatures of 15, 20, 25 and 30 degrees C. However, the mean percenta
ge of parasitized larvae increased from 13.1 to 72% and the mean proge
ny per parasitoid female increased from 14.7 to 129.4 parasitoids, bot
h significant, when the experimental temperature was raised from 15 to
30 degrees C, while their mean development time decreased fr om 75.5
to 19.2 days. Ar 25 degrees C, the virgin and mated females continued
oviposition until days 16 and 17, with a lifetime total of progeny of
397.6 (SD +/- 224.7) and 611.1 (SD +/- 128.8) parasitoids respectively
, reaching a maximum of 64.3 and 99.2 on day 2 respectively.