Meant to ask this back in July, which was peak season, but has anyone seen little circular piles of sand with pencil-sized openings in the center anywhere in Newton? They would most likely be found in hard-packed sandy soil, in sun, but within a couple hundred yards of a woody area, often, but not exclusively, on basepaths or around ballfields. One colony I’ve been monitoring is along a grassy residential berm in Needham that seems to have a lot of sand underground.
They are made by Cerceris fumipennis wasps, which are being used as a bio-surveillance tool to detect the Emerald Ash Borer before it might otherwise be detected. (They do not sting or bother people!) The EAB kills ash trees like the more publicized Asian Longhorned Beetle kills lots of species, by tunneling under the bark and destroying the tree’s circulatory system. It has been spreading outward from Detroit since 2002 (probably arriving in the US in packing crates). This summer it was detected east of the Hudson River in N.Y. for the first time, and in July was found in Prospect and Naugatuck, CT (much further east from the N.Y. border than expected), by monitoring Cerceris wasp nests. The wasps hunt Buprestid 
beetles (of which EAB is one type), and bring them back to their nests for their larvae to feed on. Monitoring involves picking up “discard” beetles, and catching wasps until they drop their prey, and collecting the prey.
I would really like find a colony in Newton to monitor next summer, and the Mass. Department of Agricultural Resources and the USDA are looking for more colonies generally. They think the EAB is probably already in Massachusetts, but not yet detected.
In Newton, ash trees only make up maybe 1-3 percent of street trees, so this particular bug would not be as devastating as it has been across the Midwest where many towns are 25 percent ash trees, because that’s what they planted when Dutch elm disease killed the elms. But they are very nice shade trees, and with our preponderance of Norway maples, anything that’s not is to be especially valued. Unlike with ALB, where infested trees are destroyed to prevent spread, healthy or lightly infested ash trees can be saved with injections that kill the EAB, which anyone with a nice ash tree would probably want to do, so it’s worth finding it early.
Can you pls expand on the second paragraph. There seems to be an interesting connection b/w two different insects but i can’t figure it out.
Julia, I just want to thank you for your input on this blog. I know very little about our ecosystem except that I really enjoy it and I appreciate that you are spreading awareness and education!
Hoss, you want me expand? I thought I was already too wordy. I’m not sure why the Cerceris wasp chooses Buprestid beetles (also known as ‘jewel’ beetles because they’re glossy & metallic). Maybe they’re big enough to nourish a wasp larvae, but not too big to carry home. It’s not just one insect and another, the Cerceris seems to go for anything in the Buprestid family that’s around. It paralyzes the beetle instead of killing it, so it stays fresh, brings it back to the nest then lays an egg on it. The egg becomes a larvae and feeds on the beetle (maybe more than one), as it winters underground, then emerges as a wasp around the beginning of July. You might like this guidebook the Canadians made:
http://cerceris.info/pdf/guidebook_biosurveillance_cerceris.pdf
It’s got great photos and a lot of detail.
Kara, I don’t generally know much about bugs, and only learned about the Wasp Watchers project through Twitter. There was a morning training session in Carlisle the end of June. If anyone is interested in being a Wasp Watcher next year, contact Jenn Forman-Orth, who is the plant pest survey coordinator at Mass. DAR, at [email protected] I think she could use more people.
You do have to be a little like ‘mad dogs and Englishmen’ standing out in the midday sun, because that’s when the wasps are most active. But it’s quite fascinating what’s going on that you don’t see until you spend time staring at the ground looking for dead insects. I was watching one Cerceris who seemed to be trying to find her hole that had gotten scuffed over, and suddenly a bird swooped down, grabbed her in its beak and flew off. Saw another dead Cerceris in pieces, her little head with its three yellow patches, her wings a couple inches away. So sad. It would be a great summer project for a high school or college student interested in biology or environmental science, or anyone with a flexible schedule or free time during the day.
One other thing — if you’ve noticed those overhead highway messages this month saying DON’T MOVE FIREWOOD, KEEP FIREWOOD LOCAL, & STOP FOREST PESTS, it’s about not spreading ALB and EAB (or other pests).