Subject: Is this an ichneumon wasp?
Location: Austin, TX
April 30, 2017 8:49 am
What is this bug? Finding them inside the house this spring trying to get out…hanging around the windows…do they sting/bite? Any house structure damage concerns?
Based on BugGuide images, we are pretty confident that this is a Grass Carrying Wasp, Isodontia mexicana. According to BugGuide: “Taken from the Internet Reference below (Penn State): The adult wasps emerge from their cocoons in early summer, mate, and the females locate a suitable nest site. She collects blades of grass and grass and hay stems to line the nest cavity. The wasp can be seen flying through the air with the blades trailing beneath her. She lands at the hole and enters, pulling the blade in behind her. After the nest is prepared, she hunts for tree crickets (i.e., Oecanthus sp.), captures and paralyses them with her sting, and transports them to the nest. She deposits eggs in the nest and the emerging larvae will feed on the living, but immobile crickets. When the larvae reach the appropriate size (in 4–6 days at 70–75° F.), they spin a cocoon and pupate. The adult wasps emerge in 2–3 weeks. In Pennsylvania, Isodontia mexicana typically produce two generations per year. Remarks These wasps commonly make their nest in the narrow track found above outer windows.” We have many more images in our archives of the nests of Grass Carrying Wasps because they are so frequently found in window tracks. Solitary wasps are generally not aggressive, and rarely sting humans, though that possibility does exist. Since they are harmless, and since it appears one individual in the images you attached might be dead from unnatural causes, we are tagging this submission as Unnecessary Carnage. Because Grass Carrying Wasps are emerging from nests formed in window tracks now that spring has arrived, and because we suspect other homemakers might be experiencing similar sightings, we are tagging this posting as the Bug of the Month for May 2017.