Wednesday, February 26, 2025

I thought you might be interested in the following conclusions, arrived at from comparing your latest list with that reported by Carril and Wilson in their Common Bees of E.N.A.

Here are the questions I was interested in.

1. How many of the species you list are also listed by C&W 57 of 114. Remarkably, exactly 50 percent!

2. Did you have some species that were among the more common of those you

recorded that C&W did not list? I didn't calculate the frequency statistics of records for

all your species, but I arbitrarily decided to see how many species with 25 or more

records were recorded by you and NOT mentioned in the C&W book.

The number of species with 25 or more records and not listed in the index of C&W was only one. This was Adrena wikella. I conclude from the above that your list of frequently observed species roughly agrees with that of C&W, that is, qualitatively at least.

3. Which genera are listed by you and not by C&W? The only ones I could detect was

Protendrea, which is quite interesting.

I didn't check the obverse question. That is, which genera are listed by C&W and

not by you. Numerically speaking, he lists 53 Genera. I didn't add up how many you list, but at least that would reveal the numerical difference in genera between your list and theirs.

I could go on with some other comparisons as well. Such as comparing

how the degree of "similarity" or coverage there was between different genera.

Here is one interesting example, using Bombus sp.. You listed 13 species.

With only five with 5 or less reports. All the other (8) had 100 or more records.

C &W also list the same 13 species in their index, 11 are listed in the text

(as "common"). The two regarded as not common were sandersoni and terricola.

You both agree about sandersoni being uncommon, but not with terricola, but I think the

latter can be confused with other species. Since the bumblebees are pretty conspicuous

overall, I'm assuming that there is something quite different about the life history, distribution, etc., of sandersoni compared to the other species of bumblebees listed by both you and C&W.

The above has been my morning exercise in learning a bit more about bees.

It also clearly illustrates how a checklist generated from frequent obs in one small

plot of land compares with that of a much broader area. To me, it's pretty amazing that

you have found 50 percent of the species of bees on your small plot compared with

all of E. N. America. I suspect you will have a very difficult time finding many more

species of bees unique to your study plot.

It is very interesting to see how many of your total number detected are represented

by just one record; that is, they are what are called singletons. You had 27. Makes one

wonder how many more there are out there that are either very hard to detect or

uncommon.

- Don

...... 🐝

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Wednesday, February 26, 2025

Vermont Bee Observations

A 1.3-acre yard yields over 100 bee species in Jericho, Vermont.

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