Digger wasp ...

The 'bee hotel', made from short lengths of hogweed stem packed into a small wooden box, that we installed in the garden in spring, hasn't attracted many residents, except for some spiders and these small but ferocious-looking digger wasps Ectemnius sp..

Their eyes are massive, like out-sized designer sunglasses, and remind me of some of the Dan Dare comic aliens that I remember from childhood. They have very acute vision and are very wary of coming out of the tubes if we get close.

I'm not sure whether they are nesting in the tubes or simply visiting to catch other tiny flies that frequent them - or maybe they're doing both. On most visits they enter several tubes rather than just one, together with the spaces between tubes, so maybe they are just foraging. There are rotting cherry tree and walnut stumps in the garden where they usually nest, tunnelling into the decaying wood and provisioning their brood with small flies.

They visit the largest as well as small tubes but when they enter the smallest they have a look inside first before they exit, turn around and then enter backwards, so maybe they're laying eggs in these. 

More digger wasp pictures here and a BWARS collection of ID photos here - I haven't identified this species for certain yet but it looks like E. lapidarius.

Washday Wasp

This little digger wasp took  fancy to our washing on the washing line yesterday. There are quite a few very similar looking species but I'd hazard a guess that this might be a female Crabro cribrarius. There's a picture of a male, with spade-shaped front legs , here. 

The smooth, almost hemispherical eyes are particularly striking.

Another Weird Wasp

Hogweed umbels are a hive of activity at this time of year, with a constant procession of insects arriving on the flat plates of flowers to either feed on pollen and necter, mate or hunt other insects. This visitor is a male slender-bodied digger wasp Crabro cribrarius which, as far as I could tell, was after plant food rather than animal prey. The female, on the other hand, is a hunter of flies, paralysing them with her sting and then incarcerating them in chambers at the end of an 8 centimetre-long tunnel that she digs in sandy soil. Take a close look at the insect in the picture and you'll notice something odd about its front legs, where one leg segment is broadened out into a flat plate. It looks like it's wearing boxing gloves.

There's a picture of a female here.

Johann Fabricius, the 18th. century entomologist who named this species, gave it the epithet cribrarius -a word meaning sieve - on account of the pattern of pale markings on the foreleg plate that makes it look like a sieve (or more like a collander, if you spend a lot of time in the kitchen). As far as I know, no one has every adequately explained what that odd-shaped leg is for. Not for digging or hunting - the female, which lacks this feature, does that. The suspicion is that males have them as an aid to gripping their mates during mating.

Crabro cribrarius is only about a centimetre long, so is easily overlooked. This one was photographed on the cliff path between Craster and Howick, on the Northumberland coast, last Saturday.