This family of wasps has earned a set of descriptive nicknames — “scarab hawks” and “scarab hunters,” because of their parasitic life cycle. Female moths search for a scarab grub (dung beetle), paralyze them with their sting and proceed to their eggs on the immature beetle. The grub is the nesting site and a food source for the larvae. The best time of year to observe this spectacle is mid-spring to the end of summer, when Scoliid wasps can be seen (and hopefully avoided) in backyards, fields, and meadows. While there, the adult wasps are usually pollinating an assortment of wildflowers.
Wasps of the Scoliid family, composing an estimated 550 species, are larger and thicker than typical wasps, making them one of the least pleasant types to encounter on a picnic (true to form, they’re also known as flower wasps or mammoth wasps). In most cases, wasps of these species are black, broken up with orange and yellow bands and stripes, which may causethem to be mistaken for bees at a distance. The rest of their visual profile greatly resembles our stereotypical depictions of wasps. Scolia range between 10-15 mm in length, with their thick bodies covered in dense fuzzy hair. The legs are patterned with hairy spokes as well. Their wings are characterized by “longitudinal wrinkles” (situated towards the apex). A rule of thumb todifferentiate the two sexes is head width. Male heads are usually wider than 3 centimeters. Female heads are less wide, most of them ranging below 3 mm. Females also have a plumper abdomen.
Written by: Robert Gibson, an undergraduate Environmental Studies student at the University of Oklahoma