DIGITAL FIELD GUIDE: WASPS (Order: Hymenoptera)
Ectemnius sonorensis
<-- from Key Location 17d
Identification features: Ectemnius is a small, one-half inch or less, black and yellow wasp. The abdomen is black with yellow rings, the first one or two of which are incomplete. Head and thorax are also black, with yellow accents: collar and either two belts, one longer and one shorter, or one longer belt and two dots. Legs are amber closer to the body and yellow towards the tips. Ectemnius is described as a “square-headed wasp,” and looking closely you can see the head is angular and as wide as the thorax. Also, if you can get a good look at the head, you can see that the eyes are large and bulging and that the antennal bases are yellow and quite low on the face.
Nesting habit and prey: Ectemnius is a solitary wasp and she builds her nest in various substrates, soil, stems, or rotting wood. Because using plant stems puts the nest in danger of being eaten by herbivores, she chooses thorny or prickly plants. Once she has prepared the nest, she hunts for adult flies.
Ectemnius as pollinator: Although she hunts flies as prey for her progeny, Ectemnius flies from plant to plant, sipping nectar for her own nourishment. Ectemnius has a short tongue, and has been observed nectaring on plants with shallow, or short-tubular flowers such as sumacs, butterfly bush, and mortonia.
