Parasitoid wasp affects metabolism of cockroach host to favor food preservation for its offspring

J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2005 Jun;191(6):529-34. doi: 10.1007/s00359-005-0620-1. Epub 2005 Apr 29.


Unlike predators, which immediately consume their prey, parasitoid wasps incapacitate their prey to provide a food supply for their offspring. We have examined the effects of the venom of the parasitoid wasp Ampulex compressa on the metabolism of its cockroach prey. This wasp stings into the brain of the cockroach causing hypokinesia. We first established that larval development, from egg laying to pupation, lasts about 8 days. During this period, the metabolism of the stung cockroach slows down, as measured by a decrease in oxygen consumption. Similar decreases in oxygen consumption occurred after pharmacologically induced paralysis or after removing descending input from the head ganglia by severing the neck connectives. However, neither of these two groups of cockroaches survived more than six days, while 90% of stung cockroaches survived at least this long. In addition, cockroaches with severed neck connectives lost significantly more body mass, mainly due to dehydration. Hence, the sting of A. compressa not only renders the cockroach prey helplessly submissive, but also changes its metabolism to sustain more nutrients for the developing larva. This metabolic manipulation is subtler than the complete removal of descending input from the head ganglia, since it leaves some physiological processes, such as water retention, intact.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anesthetics, Local / pharmacology
  • Animals
  • Behavior, Animal
  • Body Mass Index
  • Body Water / drug effects
  • Body Water / physiology
  • Cockroaches / drug effects*
  • Cockroaches / metabolism
  • Food Preservation
  • Host-Parasite Interactions / physiology*
  • Hymenoptera / chemistry
  • Hymenoptera / growth & development*
  • Larva
  • Life Cycle Stages / physiology
  • Life Expectancy
  • Mortality
  • Neck Injuries / metabolism
  • Neck Injuries / mortality
  • Oxygen Consumption / physiology
  • Paralysis / chemically induced
  • Paralysis / metabolism
  • Paralysis / mortality
  • Predatory Behavior / physiology*
  • Survival Rate
  • Tetrodotoxin / pharmacology
  • Time Factors
  • Wasp Venoms / toxicity*


  • Anesthetics, Local
  • Wasp Venoms
  • Tetrodotoxin