Effect of temperature on the bio-energetics of the larvae of Brachythemis contaminata (Fabricius) and Orthetrum sabina (Drury) (Anisoptera: Libellulidae)

Freshly emerged larvae of the 2 spp. were reared at 27 and 37 0 C up to emergence. Artemia salina nauplii were used as food. Quantity of food consumed, faeces defecated, energy converted and metabolised were estimated for the larval stages. Temperature influenced the number of instars; it varied between 9 and 13. Larval period was 170 days at 27 ° C and 101 days at 37 ° C for B. contaminata. O. sabina also extended the larval period at the low temperature in comparison to that at the high temperature. Temperature remarkably influenced the energetics parameters. Feeding and assimilation rates were highest at 37 °C. However, the maximal efficiency of net conversion occurred at 27 0 C,