Effect of Temperature on the Development and Reproduction of a Cereal Aphid Parasitoid, Lysiphlebia mirzai Shuja-Uddin (Hymenoptera: Braconidae)

ABSTRACT

Exposure to different constant temperatures (12, 17, 22, 27 or 32°C) during the entire life-span of female Lysiphlebia mirzai variously affected its longevity, life-table parameters, developmental rate, and mortality of developmental stages of the progeny. The parasitoid develops much faster at 32°C than 12°C. Lower threshold temperature for the development (t₁) was 3.02°C and predicted time-to-adult 339.93 degree days. Higher percent mortality occurred at 32°C and 12°C than at 22°C. The adult survived much longer (17 days) at the lower extreme temperature than at the higher one. However, net fecundity (daughters/female) and total fecundity rates (progeny/female) were lowest at 12°C. The female produced the highest number of daughters (163.8) and progeny (242.6) at 22°C. Life-table parameters were temperature dependent; r_m was greater than 0.3 at ≥ 22°C. The results reveal an optimum range of temperatures at which L. mirzai performs well. Most of the life- table parameters vary little between 17 and 27°C, thus, the parasitoid may be adapted for a wide range of temperatures and thus well suited for biocontrol of the cereal aphid Rhopalosiphum maidis, in areas where temperatures vary within this range, as in the plains of north India.