DIGITAL FIELD GUIDE: WASPS (Order: Hymenoptera)
Myzinum sp.
<-- from Key Location 12a (male) or 17a (female)
Identification features: This is an easily recognizable wasp, and, unusually, it is the male Myzinum that is most distinct. He is distinctly slender, and his thin abdomen is longer than his head and thorax together. The abdomen is black with complete yellow rings around it. The tip of the abdomen has a large up-curved hook that suggests he could deliver a vicious sting, but the males cannot sting. It is most likely a mating implement. His head and thorax are black with yellow accents: shoulders, collar, and three marks on the back. Face and legs are also yellow. The male is often seen holding his long abdomen curled slightly around vegetation.
The female wasp is also black with yellow accents. But her abdomen is not so narrow (specialized for egg laying), and she does not have an apical hook structure. Her yellow abdominal rings are wider than those on the male, and they are not complete. Instead of a yellow face, she has yellow marks outlining the inner margin of her eyes. And instead of three yellow marks across her back, she has only two.
Males and females are covered with erect white hairs. These hairs are not always visible, but with the sun behind the insect, a distinct fuzziness is detected.
Nesting habit and prey: The female Myzinum does not build a nest, rather, she lays her eggs directly on scarab beetle larvae (grub). She lays one egg on a grub. The grub goes about its business of eating, and when the wasp larvae hatches it begins devouring the grub, starting with the non essential parts. The wasp larvae grows, molts several times, then as it gets ready to pupate (metamorphose), it finally kills the grub by eating the last of it.
Myzinum as pollinator: Myzinum provides its young with beetle grubs, but sips nectar from flowers for its own sustanence. Myzinum has a short tongue and has been observed on plants with shallow, white flowers such as soapberry, Texas kidneywood, and croton, as well as the pink flowers of antelopebush (Purshia), and purple flowers of Mexican thistle.
