Wasp type bug – drillig holes
Location: North Vancouver, Canada
August 30, 2011 10:15 pm
We recently noticed loads of sawdust on our deck one morning, looked up to find a few little perfect round holes in a wood support beam outside our apartment. Since then we seen quite a few of these wasp like bugs coming and going through the holes. Not sure what they are though??.
Signature: S

Square Headed Wasps

Dear S.,
Many Solitary Bees, both native and introduced, nest in small holes in wood.  Though they are solitary Bees, they often nest in colonies with each female provisioning for her own offspring.  We believe these are Mason or Leaf Cutter Bees in the family Megachilidae, though we are not certain of the species.  We don’t believe the Bees have excavated the holes, but rather, they are utilizing the exit holes of some wood boring insect.  See BugGuide for additional photos and information on these fascinating Bees.  Gardeners who want to encourage native Bees to nest near plants that need to be pollinated might enjoy this informational Make a Bee Hotel web page. 

Square Headed Wasp

Correction Courtesy of Eric Eaton
Ah, well, they are not bees, for one thing!  These are square-headed wasps in the family Crabronidae, subfamily Crabroninae, and tribe Crabronini.  Genus?  Not sure, but Ectemnius and Lestica are both possibilities.  Ectemnius hunt flies, while Lestica hunt moths.


Location: Canada

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