October Bee Update – Museum visits and dealing with Nomada + Sphecodes

Hello again!

We are still hammering away at our remaining 2020 bees. The past several weeks I have been focusing on Nomada and Sphecodes, which are both groups of parasitic bees that sneak into other bee nests. These two groups are both frustrating and in dire need of revision to describe, update, and lump species groups. But, I am stuck with the taxonomy as it is now, so for some of them I might just end up lumping them as species group A, B, C, etc. I will continue to try to work on them and figure out what I have, but as with Lasioglossum, there is a learning curve that is best aided with good reference specimens.


Example pinned specimen of Sphecodes from the museum.

These are black and red bees in the family Halictidae. We have 159 specimens from our 2020 bowl samples. There are a few species that are easy to identify, like the ones with 2 submarginal cells or the species with the large bump on the top of the head (Sphecodes heraclei).

All bees have 2 compound eyes on the side of their head and 3 simple eyes (ocelli) in the top of their heads. For Sphecodes heraclei, it has a distinct mound in the center between the 3 ocelli.

The remaining Sphecodes are sorted into groups based on whether they have a tooth on their mandible, the punctation on the scutum (plate on back), abdominal punctation, and antennal length ratios.


Example of a female Nomada from the museum

The nomad bees are small to medium sized parasitic bees in the family Apidae. They are variable in color, but are often red, yellow, or black, with a variety of the colors mixed in. These bees are easily mistaken for predatory wasps given their lack of hair and striking coloration.

There is a large group of them that have a tooth on the mandible, that per comments from other taxonomists, we have decided to just lump as Bidentate Group. That accounted for about 40 specimens. That still leaves over 300 of non-bidentate Nomada. This group is a mess and needs taxonomic work, but I have tried to at least sort things. After sorting out the bidentate specimens, we then sorted them by size and then sex, since the males and females have very different characters used to identify them. For the females, we then sorted by clypeus color (red, orange, yellow, or black) and from those we sorted based on abdominal banding patterns (whether yellow bands were complete, narrowly broken, widely broken, or absent). For males, we sorted by scutellum color (red, black, black with yellow, black with red, and yellow), and whether the antennae had spines on the 3rd segment.

Example of one of our male specimens showing a spine on the underside of the third antennal segment after the scape and pedicel

Needless to say, we have things more organized, but still lacking names for several of these groups. So I decided to try to get reference specimens so I can more easily compare and learn the groups.

Trip to the Triplehorn Insect Collection:

Thankfully, we were allowed access to research specimens at the museum, so I spent a day looking through the collection and pulling specimens.

It was exciting to see my old bees from my undergraduate and graduate work. They now make up a nice portion of the bees in the museum.

The collection is many rows of movable cabinets that are on racks to save space.

Thankfully, most of the bees in the museum are in this one aisle, so I didn’t have to move the units very much to get to what I needed.

I started with looking at bees in a different parasitic group: Holcopasites. I was hoping to find a reference specimen to compare with for the dark abdomen species, but unfortunately there are none available here. I did stumble upon the H. elegans paratype that has since been weirdly lumped with H. stevensi ( a banded, not spotted species)

This is H. knulli, which has since been replaced as H. stevensi as well. Calling these two individuals the same species seems odd to me, so I expect someone to eventually go through and revise this group.

I also photographed the museum’s only specimen of Nomada tricurta. This rare bee is only listed from 5 localities on discoverlife. I did not borrow this specimen, but I was able to borrow about a dozen other species of Nomada.

I then spent time looking for Sphecodes reference specimens, but turned up mostly empty handed. Almost all of the collections Sphecodes are only identified to genus and thus I will have to search elsewhere for species level reference specimens. Onwards!

While looking through the collection, I also saw some other cool weird bees. This is a parasitic bee from South America that has a striking blue color!

Who can say no to this striking blue?

And this weird bee was in the unsorted bee boxes. I think it is probably a weird South American species of Ceratina. Check out those weird facial maculations!


Anyways, that is all I have for now. I will keep on chugging along and see what I can work out with the aid of the new Nomada references. I’m also looking into tracking down some Sphecodes reference specimens, so if you are a bee taxonomist and know of some that are easy access, let me know!


2 thoughts on “October Bee Update – Museum visits and dealing with Nomada + Sphecodes

  1. I really admire your work! Does Cleveland Museum of Natural History have bees in its entomology collections?

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