Varying prey nutrient quality affects growth rate and stoichoimetry of riparian spider (Tetragnatha nitens)

The growth and development of subsidized consumers may be limited by prey nutrient quality.  Significant interspecific variation of nutrient stoichiometry in prey species may create an imbalance in predator body stoichiometry.  Due to this imbalance, predators may suffer losses of growth and development time, and/or differentially excrete or store excess carbon (C) or nutrients in order to maintain body stoichiometry.

For this experiment, I tested how different diets of prey (Culex quinquefasciatus, Chironomus dilutus, and Drosophila melanogaster) of varying nutrient quality affected the growth and development of predatory terrestrial spiders (Tetragnatha sp.).  Spiders fed on mosquitoes (Cx. quinquefasciatus) had significantly lower body nitrogen (N) and higher C-N ratio than spiders fed on midges (C. dilutus) or fruit flies (D. melanogaster).  Although spiders fed on mosquito diet had lower growth rate during early instars, growth rate increased during later instars compared to spiders fed on other diets.  Spiders fed mosquitoes also had significantly lower δ13C ‰ than mosquitoes they were fed on.