Last rain a week or so back I noticed approx 100 small holes in rear lawn next AM, again today after rain last night same amount of holes but larger in diameter ( 1-1.5 cm )only at rear. We have a water easement at back side that has been dry most summer. We have had very dry summer in Dundalk Ont. this area of lawn receives mainly sunlight. There are no surface burrowing marks and wonder if this is a vole or insect are what problem. I have found similar picture on web to what I have ( attached ) Thank-you
Especially given the timing, what you might be looking at is the burrow of the Cicada-Killer Wasp (Sphecius speciosus), which is active in July and August. It’s a large, ground-nesting wasp that emerges in late summer, and lays its eggs on paralyzed adult cicadas drawn into burrows in the ground. Despite their significant size, they seldom sting humans (and males have no stinger) and their sting is relatively weak. For more information and pictures, check out these links to Cornell University’s Master Beekeeper and to NC University’s Insect Museum . There are also excellent pictures here.
Someone else posted a question on our website titled Burrow Holes in the Garden which also sounds very similar to your problem. I would suggest looking over that response as well as checking out this useful site which helps you identify if an animal might is digging up your lawn.
I hope this helps identify your new neighbour.