#weevil wasp

Weevil wasp (Cerceris insolita)

September 17, 2020

Southeastern Pennsylvania

Little guy!! On a flowers!! Living its best life

Weevil Wasp - Cerceris sp.

Is this a familiar Wasp gracing the blog again? Not exactly, but it does resemble other insects than have been added to this blog quite closely; the Beewolf Wasps (Philanthus species) and the Wasp-Mimic Sawfly (Allantus viennensis). The former shares a textured body pattern across its abdomen with this Wasp while the latter Sawfly is also a close match in terms of colors, body shape and wing posture (and this Wasp may also help strengthen its mimicry as a result). Alas, this Weevil Wasp fits into its own little distinct area, but does share a good amount of behavioral traits with Beewolves. Females will dig burrows in soil and lay eggs inside which will be provisioning with the carcasses of captured insects. In particular, this Wasp genus seems concentrate their efforts on capturing adult Beetles rather than grubs! Weevils are a common prey item, being these Wasps the common designation seen above, though some species are recorded preying on other Wasps and even Bees! 

While I haven’t been able to narrow down the specie, I’m absolutely certain on the genus due to these individuals’ abdomens. Not only textured, the abdomen also has constrictions where the yellow bands are which gives the abdomen a look with more depth and contour to it. It looks like it’s bulging out from the bands because it’s too big or the bands are too tight! While this specie looks very small, the females can haul an armored Beetle back to the den with ease to store it. They manage this using large mandibles to carefully grip the Beetle (for further reference at the moment, refer to Beewolves as they show pronounced mandibles) and then drag in underground after landing. While it’s difficult to tell the gender of these Wasp individuals due to the distances and angles of the camera shots, you can tell the difference based on a few factors. There’s the aforementioned mandible size and as well, female Wasps will also have facial projections on the bottom half of their head. Picture 4 offers a possible glimpse of this, just below the compound eye, like a little spike.