The effect of wounds on desiccation of prey: implications for a predator with extra-oral digestion

Predators that inject prey with proteolytic enzymes, thereby breaking down their tissues for subsequent ingestion, run the risk that desiccation will hinder eventual retrieval of resources from these prey. Wounds made in capture might exacerbate this problem. However, desiccation rates of small syrphid flies Toxomerusmarginatus (Diptera: Syrphidae) killed by juvenile crab spiders Misumena vatia (Araneae: Thomisidae) and intact dead syrphid flies did not differ over the normal period of feeding, though desiccation rates in shade and sun differed several-fold. Neither the size of the spider (and presumably the size of the wounds it inflicted) nor the location of the wounds on the flies' bodies affected desiccation rates. Thus, this tactic of prey handling does not exact an added processing cost on Misumena.