Bugging You From San Juan Island

Menacing Murder Hornets are making headlines everywhere these days and giving many of our beneficial wasps a bad rap.  Before you grab that can of bug spray, follow along for the next week or two while I profile the good guys and give you tips on how to ID the ones you’ll see on the San Juan Islands.  

Wasp #1 – The Western Sand Wasp (Bembix americana)

On San Juan Island, if you’re out along the beach bluffs on the west side or anywhere at American Camp, Eagle Cove, or Jackson’s Beach and the nearby quarry, you may notice them hovering and darting about above the sand or spots of bare earth.  Western Sand Wasps are solitary digger wasps in the family Crabronidae.  Males and females emerge simultaneously and their entire adult life is to sip nectar from flowers, mate, and reproduce.  

After mating, it is the female who will provision her nest.  She scours the sand and nearby areas, hunting insects and arachnids to supply her developing offspring in underground burrows.  She will oviposit one egg in a single burrow, leaving it with a zombied insect, continuing until all her eggs are laid.  But her work is not over.  She must continue to check and feed each of her larvae in their individual burrows after the eggs hatch, making sure that they do not starve as they develop.   Fast fact…a single larva can eat more than 20 flies before it pupates!  

So she digs…and digs…and digs!  These wasps are able to dig so fast, they can disappear under the sand in a matter of seconds.  

Human or Pet Risk factor – LOW  

Unless you are walking barefoot in the sand and mange to step on one of these, you are highly unlikely to be stung.  Wear foot coverings and enjoy your hike or picnic.  They’re not going to murder you!

References and other interesting reading:

Bugguide: https://bugguide.net/node/view/79847

Eaton, E. 2015. Sand Wasps, Genus Bembix. Bug Eric. http://bugeric.blogspot.com/2015/01/sand-wasps-genus-bembix.html

Garvey, K. 2016. An Insect You May Overlook. The Bug Squad. UC Davis. https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=21912

Malinek, J. 2016. Bembix americana. Janamalinekphotoblogspot. http://janamalinekphoto.blogspot.com/2016/08/western-sand-wasp-bembix-americana.html