When the parasitic wasp Microplitis croceipes experiences odors while feeding on sugar water, it learns to associate the odors with sugar and thereafter exhibits typical food searching behavior in response to the odors. Previous studies have shown that this wasp can be used for detection of the small amount of explosives or other volatile chemicals. In the present study, we examined if this wasp can learn and report narcotic odors. Males of M. croceipes were trained to link sugar water with pseudo-narcotic scents that have been used for training narcotic detection dogs, and their behavioral response to the trained odors was observed. The males that had been given either an odor or sugar water did not show any positive response to the odors. However, when the wasps were given a combination of sugar water and either the pseudo-Cocaine, Heroin, LSD or Marihuana, they quickly learned to associate the odors with sugar, and thereafter positively responded to those odors. Our results suggest that this wasp can be used for detection of these narcotics.