As wheat and barley fields continue to mature, fuzzy, white “egg-like” clusters may be observed (Fig. 1). Sometimes a dead caterpillar can be found alongside the fuzzy cluster. These white “egg-like” clusters are yet another species of @FieldHeroes! Cotesia parasitoid wasp cocoons arise from parasitoid larvae that develop within a single lepidopteran caterpillar then the parasitoid larvae burst out through the host’s body wall – in this case, likely from a wheat head armyworm (Dargida diffusa). Researchers are seeking intact parasitoid cocoons in order to learn what species of Cotesia is parasitizing the wheat head armyworm.
Request for help: If you find intact samples (i.e., developing Cotesia still within cocoons but NOT open as in Fig. 2), please contact Tyler.Wist@agr.gc.ca to arrange collection and shipping of the cocoons and any associated lepidopteran caterpillars. Remember, intact cocoons NOT with open ends are needed.