Two different leaf-cutter bees nesting in same plank?

[Jessicajil]

I live on a tidal river estuary in West Sussex and the semi-rotten plank once formed part of the jetty. There are two separate holes a few inches apart, and there seem to be two different spp. of leaf-cutter bees nesting in them. I think they are Megachile spp. The one nesting in hole 1 has a narrow posterior to its abdomen. First two photos.




The one nesting in hole 2 has a wider abdomen with what appear to be white hairs on the underside. The next two photos.


I am not absolutely sure which hole this bee came out of as I was watching through the camera and did not realise until afterwards that they may not be the same species. It is in front of hole 2.



I have seen both insects taking leaves in, though I did not get a good photo of the bee in hole 2 doing so.

[Matt Smith]

They are certainly Megachilesp. bees, but I would not like to guess the species.

[JRsbugs]

The white hairs under the abdomen is pollen.

[Jessicajil]

Originally Posted by JRsbugs

The white hairs under the abdomen is pollen.

I wondered if it was, but was surprised it was so white? How many plants would have white pollen? Might it be from some of the estuary plants?

[JRsbugs]

Look at this google search "flowers with white pollen".. but I have white species Campanula with white pollen, there has to be plenty of other flowers.

Google

[Jessicajil]

Originally Posted by JRsbugs

Look at this google search "flowers with white pollen".. but I have white species Campanula with white pollen, there has to be plenty of other flowers.

Google

I have vast quantities of bindweed in my garden .. I am so glad it is useful to something, especially these little bees.
Can anyone tell which species they are?

[JRsbugs]

Originally Posted by Jessicajil

I have vast quantities of bindweed in my garden .. I am so glad it is useful to something, especially these little bees.
Can anyone tell which species they are?

I'm leaving wildflowers in my garden too, they attract many more insects and of course provide food where there's little flourishing elsewhere.

You would really need good close shots of the front leg (tibia for female) and top of the tail end, other shots can help too such as the mandibles and colour of scopa hairs under the abdomen.

[Jason Green]

Afternoon Jessica, and welcome to WAB!

Assuming these are common garden species then the first, going on the basis of the posterior hair-bands on the abdomen is probably Megachile centuncularis. The second species shows more hair clothing the margins which crosses the whole length. Was it bigger? This looks to be more like M. willughbiella.

Besides the IDs based on my specimens I have to say Matt's advice RE stopping at genus is most sensible! You seem to have good field-intuition.

Take care,

Jason

[Jessicajil]

Originally Posted by Jason Green

Afternoon Jessica, and welcome to WAB!

Assuming these are common garden species then the first, going on the basis of the posterior hair-bands on the abdomen is probably Megachile centuncularis. The second species shows more hair clothing the margins which crosses the whole length. Was it bigger? This looks to be more like M. willughbiella.

Besides the IDs based on my specimens I have to say Matt's advice RE stopping at genus is most sensible! You seem to have good field-intuition.

Take care,

Jason

Hello Jason,
I am not sure of the relative sizes, and I don't think I can use my original photos to gauge that. I'll keep a look out on the next sunny day and see if they are still nesting.
Jess

[Jim Ford]

Here's 'my' Megachile:



Nice, industrious little creatures. Unfortunately the nest later received the attention of a parasitic wasp:



Jim