Jan 24th – Andrena progress!

I made it through the majority of the ~2000 Andrena  specimens over the last few weeks, with about 300 specimens left to go. In the last blog post, I created a poll to see what people thought might be the most abundant species from our samples.

Opinion Poll Results

Many people thought that the non-native species, Andrena wilkella, would be the most abundant in our samples, but there were a few people betting on nasonii or literally any other species of Andrena.

I am happy to report that our most abundant species of Andrena in our samples is Andrena nasonii! Andrena violae and cressonii were also rather abundant. Andrena wilkella never stood a chance at being the most abundant in our bowl trap samples.

Andrena nasonii is a fun species of mining bee and one that forages on a wider variety of plant species. Most species of Andrena are considered specialists, so it is unusual for a species in this genus to forage on such a wide range of plants.

A lot of Andrena look superficially very similar, with dark brown bodies and typically light colored hairs. A key character to recognize bees in the genus Andrena from other brown bees is that they have a depression on their head with small inset hairs. These are typically referred to as facial fovea, but some people like to call them vertical eyebrows. These are not always easy to see in a photograph.

Andrena nasonii has a distinctively triangular hindleg. There are a couple other species that do have triangular legs like this, so we have to check other characters as well.

Andrena nasonii also has really wide facial fovea (vertical eyebrow patches between the compound and simple eyes at the top of the head). The ocelli (simple eyes – the 3 dots in center of head) are also really close to the edge of the top of the head. Another good character is a set of small bumps on the underside of the thorax, but I did not get a good photo of that yet. We are hoping to get an imaging system up and running soon so we can show you better photos. For now, we are stuck with images taken through the microscope with my cell phone.

Once I get through the Andrena, my goal is to take a few days to work on the specialist bee project and get those reports out too. If you are looking for a challenge for 2022, consider signing up to help with the specialist bee project, which involves more targeted sampling of bees directly from flowers. See more here: https://u.osu.edu/beesurvey/native-bee-survey-via-specimen-collections/120-2/

Lab reading:
We have started more regular discussions of academic papers in the lab. Below are a few that we have read recently.

López-Uribe et al. 2016. Crop domestication facilitated rapid geographical expansion of a specialist pollinator, the squash bee Peponapis pruinosa.

Danforth, B. et al. 2013. The Impact of Molecular Data on Our Understanding of Bee Phylogeny and Evolution. Annual Review of Entomology. 58:57-78 https://doi.org/10.1146/annurev-ento-120811-153633

Larkin, L.L., Neff, J.L. & Simpson, B.B. The evolution of a pollen diet: Host choice and diet breadth of Andrena bees (Hymenoptera: Andrenidae). Apidologie 39, 133–145 (2008). https://doi.org/10.1051/apido:2007064.

McAulay, M.K., Killingsworth, S.Z. & Forrest, J.R.K. Understanding pollen specialization in mason bees: a case study of six species. Oecologia 195, 559–574 (2021). https://doi.org/10.1007/s00442-020-04786-7https://link.springer.com/article/10.1007/s00442-020-04786-7

Spear, D., Silverman, S. and Forrest, J. 2020. Asteraceae Pollen Provisions Protect Osmia Mason Bees (Hymenoptera: Megachilidae) from Brood Parasitism. The American Naturalist. 187:797-803.

All for now,

MaLisa