DIGITAL FIELD GUIDE: WASPS (Order: Hymenoptera)
Eucerceris sp.
<-- from Key Location 22b
Eucerceris canaliculata
Eucerceris fulvipes
Eucerceris melanovittata
Eucerceris montana
Eucerceris pimarum
Eucerceris rubripes
Eucerceris tricolor
Identification features: Eucerceris is a common floral visitor in the Gardens. At least seven species have been identified. Unfortunately, they are small—about one quarter to one half of an inch long—and look very much alike. Some species we observed are prominently yellow, with red and/or black markings. Some are black with yellow, or pale yellow to white, abdominal bands. If the abdomen has prominent yellow bands alternating with thinner black bands, then the head is also black. If the prominent yellow abdominal bands alternate with narrow red bands, then the head is also red. The abdomen is strongly segmented. Eucerceris belongs to a group of wasps known as the “square-headed” wasps, and this character may be useful in distinguishing Eucerceris from other small wasps. Its head is big, as wide as or wider than the thorax, and angular.
Nesting habit and prey: Eucerceris is a ground-nesting wasp, and although solitary, nests in aggregations, perhaps because suitable soil conditions are scarce. Females builds the nest and hunt for provisions. Eucerceris is known as a weevil wasp, indicating their choice of prey. The female hunts adult weevils (Cucurlionidae).
Eucerceris as pollinator: As an adult Eucerceris flies from plant to plant, sipping nectar from flowers for its own nourishment. It has been observed nectaring on plants with shallow flowers, including soapberry, mortonia, sumacs, crotons, and various composites.
