Bumblebees for ID

[cyberinsekt]

Two bumblebees for ID, photographed along a ride in SSSI woodland on the Somerset/Wiltshire border.

Habitat and general probability suggest this one is B.pascuorum but I cannot see any black hairs on the abdomen. Can anyone confirm?





This looks like a male B.rupestris - is this amount of yellow on the abdomen typical?

[JRsbugs]

I often have B. pascuorum with no black apparent on the abdomen, more so at this time of year. New queens are often very hairy and lack black. If you have very close shots you can mostly find a few black hairs.

Bombus rupestris males are very variable with different amounts of yellow. If it has black hairs on the face and yellow hairs on the body with a red tail, you can say it's male B. rupestris.

Janet

[Matt Smith]

First one is a male of one of the "orange" carder bees. It is probably B.pascuorum - these can be very orange indeed and some individuals do lack black hairs. Given your location it is probably this species, but a good look at the genetalia under a scope would be needed to confirm the species.

No 2 is a male B.rupestris.

[Jason Green]

Morning all,

How would you prepare the genitalia of one of these, should the individual be 'in question'? I've seen a few male bees under the 'scope but never quite 'got a handle' on where it resides. It doesn't seem to be as simple as Syrphids.

Take care,

Jason

[Matt Smith]

Originally Posted by Jason Green

Morning all,

How would you prepare the genitalia of one of these, should the individual be 'in question'? I've seen a few male bees under the 'scope but never quite 'got a handle' on where it resides. It doesn't seem to be as simple as Syrphids.

The genital capsule in bumblebee males is normally carried inside the end of the abdomen when "not in use" and is not usualy visible in a live insect. To see the capsule in a voucher specimen, you need to gently separate the last tergite and sternite of the abdomen and carefully pull the capsule out.

This is best done with a pair of fine tweezers or an thin entomological pin with a little "hook" on the end (easy enough to make by bending the very end of the pin). The capsule is a sturdy chitinised structure attached to some softer stretch membranes, so it usually extracts fairly easily, sliding out and rotating downwards.

Extract it until the whole capsule is visible, if fully extracted the capsule tends to "wedge" under the abdomen so it stays in place as the specimen dries. In some older collections the whole capsule was removed and glued to a small pice of card mounted on the same pin as the bee, but this runs the risk of loosing the capsule at some point.

[JRsbugs]

Originally Posted by Jason Green

Morning all,

How would you prepare the genitalia of one of these, should the individual be 'in question'? I've seen a few male bees under the 'scope but never quite 'got a handle' on where it resides. It doesn't seem to be as simple as Syrphids.

Take care,

Jason

Surely you could have asked this privately Jason, and not on this ID thread?

[Jason Green]

Thanks a lot Matt, very useful. You 'ought to do this professionally!

[cyberinsekt]

Thanks folks.