Journal archives for September 2022

September 04, 2022

Natural Land Divisions

Back in February I was at a workshop showing the natural land divisions in my state, IL. It was interesting and later when looking at range maps for different bees I noticed that some species ranges seem to line up with where a division line is. For some species this has been hard to see: some species have limited observations, and some areas have noticeably higher human population which may be skewing the data. But there are two species that have a decent amount of observations that are interesting.

Bombus rufocinctus (Red-belted Bumble Bee). There is a noticeable drop in observations when you hit the Wisconsin Driftless Division, in all four states that contain driftless. Also drops in the Grand Prairie Division.

Xylocopa virginica (Eastern Carpenter Bee). This one is interesting. Commonly found in the Northeastern Moraine Division, but in the Rock River Hill Country, all of the observations are right next to the border of either the NE Moraine or the Grand Prairie.

Less commonly reported but still noticeable:
Melissodes desponsis (Eastern Thistle Longhorn) Range appears to run around Rock River Hill Country.
Anthophora abrupta (Abrupt Digger Bee) Also drops on the Rock River Hill Country division.

I don't know if this is due to lower human population in the Hill Country and Driftless, or if this is more related to these species being more urban than ag land adapted, or if there is and land based reason that a division line would have any influence. Especially odd considering that most of these are generalist pollinators and Xylocopa at least don't nest in the ground. There are species of Andrena that have a ground preference, but I'm not sure what's in play here.

Posted on September 04, 2022 01:28 AM by neylon neylon | 0 comments | Leave a comment

September 22, 2022

Color Variation in Bees

Occasionally you run into a bee that looks like it should be one species, but has noticeable red, yellow, or white in an area that it wouldn't normally have. This can make identification difficult, and a great example of why you can't just focus on one field mark but have to look at the whole bee when making an identification.

What causes this?
Color variation is usually caused by damage to the bee during the larval stage. Can also be leucism (kind of partial albinism), or melanism.

Affected species?
Most commonly reported in Bombus impatiens, but many other Bombus species have been recorded with variations. Occasionally seen outside of Bombus.

Bombus impatiens melanistic Appearing to be a bimaculatus.

Bombus griseocollis

Bombus bimaculatus

Bombus perplexus Dark form

Bombus fervidus Leusistic Not a color variant, just weird hair loss making it appear to be something else.

Bombus affinis

Bombus pensylvanicus

Outside of Bombus:
Anthophora abrupta
At the time of writing this, there is no literature that mentions color variations for A abrupta, although I am aware of a paper being written. To the best of my knowledge, this observation was the first time this variation was noticed.

Posted on September 22, 2022 09:08 PM by neylon neylon | 0 comments | Leave a comment