New backyard bugs: Megachile albitarsis and Lasioglossum lepidii

White-footed Leaf-cutter Bee (Megachile albitarsis). Boca Raton, FL, September 3, 2015.
Earlier in September I discovered yet another kind of bee on my property: a leaf-cutter bee in the genus Megachile, this one has huge furry white legs and an amazing two-tone eye. Its "common name" is basically just a translation of its taxonomic name: Megachile albitarsis, the white-footed leaf-cutter bee:
White-footed Leaf-cutter Bee (Megachile albitarsis). Boca Raton, FL, September 3, 2015.

White-footed Leaf-cutter Bee (Megachile albitarsis). Boca Raton, FL, September 3, 2015.

Like most of the other bees I've found in the area, this one was cruising from flower to flower exploring the Spanish Needles for nectar and pollen:
White-footed Leaf-cutter Bee (Megachile albitarsis). Boca Raton, FL, September 3, 2015.

White-footed Leaf-cutter Bee (Megachile albitarsis). Boca Raton, FL, September 3, 2015.

And just recently, I captured an image of a teeny tiny bee that had enough detail in it to enable John Ascher, the bee guru at Bug Guide, to offer an identification: Lasioglossum lepidii, a halictid. I have the signal honor of being the first contributor with an image of this species in bugguide.net:
Lasioglossum lepidii, a tiny bee in the halictidae. Boca Raton, FL, September 10, 2015.

Lasioglossum lepidii, a tiny bee in the halictidae. Boca Raton, FL, September 10, 2015.

In the guide for the subgenus to which this bee species belongs (Dialictus), the following rather desperate note is offered:
Extremely difficult to ID to species, even under the microscope. They are so morphologically monotonous that breaking them into species groups isn't really an option. Many species can only be IDed by the relative density of punctures on the surface of the bee.
However: "The limiting factor is resolution of the images. If we could clearly see antennal proportions and scutual sculpturing many species identifications would become possible." (Comment by John Ascher).
I'm glad my two images were enough for him to give an ID of this guy this time around. (An earlier attempt from last October did not provide enough detail for a positive ID. The new 200-mm macro might have made the difference. Or the fact that I used a tripod this time.) Now that I'm up to 7 or 8 species for the yard, it's time to start listing them all so I can keep track of them; the ubiquitous Apis mellifera, the European Honeybee, is of course a daily visitor as well.
  • Agapostemon splendens, a halictid bee.
  • Coelioxys dolichos, a cuckoo-bee in the megachilinae.
  • Halictus poeyi, a halictid.
  • Lasioglossum sp., a (very small) unidentified halictid. Presumably L. lepidus (see next list item).
  • Lasioglossum lepidii, very small (and first picture in Bug Guide!) halictid.
  • Megachile petulans, a megachilid.
  • Megachile sp. Subgenus Chelostomoides, one of several hard-to-differentiate species.
  • An unidentified megachilid, perhaps "just another" M. petulans.
  • Megachile albitarsis.
So. There you have it. To my surprise, only three (or perhaps four) "sweat bees" (halictids) and four (or perhaps five) leaf-cutter bees (megachilids), in addition to the ubiquitous honeybee For those who are curious, here's a little gallery of all the bees I've seen:    

Butterflies and Bees: out takes

Pollination is serious business--get in line, busy bee!
You find some funny things when you start reviewing your photo files looking for images to delete (file sizes are big these days!). So the other day I posted a photo sequence of a Lasioglossum bee [UPDATE: chalcid wasp] lying in wait inside a flower to surprise a Cassius Blue butterfly in the act of taking a drink. In case you missed it, here's one of the images: Yup. But I'm not sure I want it now! Another image I took that day was one that I hadn't even considered posting. It was a typical throw-away image of a Martial Scrub-Hairstreak nectaring so deep behind a flower cluster that you couldn't even see its head. It was both underexposed and (at first glance) uninteresting. Here's a crop of the main subject, with a bit of Photoshop processing to try to bring out some detail in the badly exposed image (shooting darkish wings against a brightly sunlit white wall isn't easy):
Martial Scrub-Hairstreak (Strymon martialis), head-deep in the weeds.

Martial Scrub-Hairstreak (Strymon martialis), head-deep in the weeds.

Normally I discard these underexposed images without even a second thought, but for some reason right before I hit "delete" my eye was drawn to the left of the image. I decided right away to save this one despite its rather poor technical quality because it was such an interesting and serendipitous capture of insect behavior: Pollination is serious business--get in line, busy bee!There's another (maybe even the same one as in my previous post!) bee waiting in line for this flower! Here's the full size detail of the bee; just enough to see that it is indeed a bee, and most likely in the genus Lasioglossum[UPDATE:wasp in the family Chalcidoidae]. Lasioglossum_20150903 If I'd been trying, I'd probably have had to spend hours and hours, and I still might not have been able to get even this nice an image of this tiny bee in flight. I'm amazed by the people who can take good images of flying bees insects.  

New backyard insect: Megachilid bee sp., subgenus Chelostomoides

Being a backyard naturalist has its ups and downs. It's fun to get to know your little corner of the earth well enough to know when something new (to you, if not to science) appears there. Lately I've been noticing how many different species of bees there are. Of course the most common bee in the yard is the good old honeybee, imported long ago from Europe. But in addition to Apis mellifera there are scores of other species. All of them are much harder for the uninitiated to identify, and even the initiated often can't tell them apart without a specimen and a microscope. No matter how good one's photographic skills, wild, unrestrained bees are unlikely to sit still for their portraits long enough to be sure of capturing enough field marks to guarantee a successful identification. Still, one can make educated guesses once one becomes familiar enough with the local apifauna. In my yard I can be(e) fairly certain of the following four species: Agapostemon splendens, the gorgeous little bee with the green thorax and, depending on sex, green (for the girls) or black-and-yellow (for the boys) abdomen. Here's one on one of our 11 official state flowers in the genus Coreopsis, C. leavenworthii:
Sweat bee (halictid) Agapostemon splendens on Leavenworth's Tickseed (Coreopsis leavenworthii). Boca Raton, FL, May 12, 2015.

Sweat bee (halictid) Agapostemon splendens on Leavenworth's Tickseed (Coreopsis leavenworthii). Boca Raton, FL, May 12, 2015.

Megachile petulans, the leafcutter bee with the big head and stout abdomen, loves to appear on my patches of Dune Sunflower (Helianthus debilis):
A leafcutter bee (Megachilid petulans). Boca Raton, FL, October 5, 2014.

A leafcutter bee (Megachilid petulans). Boca Raton, FL, October 5, 2014.

Halictus poeyi is the small bee with the low profile:
Sweat bee (Halictus poeyi). Boca Raton, FL, February 7, 2015.

Sweat bee (Halictus poeyi). Boca Raton, FL, February 7, 2015.

Coelioxys dolichos, the cuckoo bee (the "common" name is Carpenter-mimic cuckoo leaf-cutter), looks pretty wicked:
The cuckoo bee with the crazy name: Carpenter-mimic Cuck-leaf-cutter (Coelioxis dolichos). Boca Raton, FL, May 8, 2015.

The cuckoo bee with the crazy name: Carpenter-mimic Cuck-leaf-cutter (Coelioxis dolichos). Boca Raton, FL, May 8, 2015.

I'm familiar enough with the GISS and markings of these four bees that I can be reasonably sure which one I'm looking at even before I take the picture. That reasonable surety is bolstered if I get a clear enough photo to bring up on my camera's screen, and if there's still doubt, taking it inside to view on the large monitor will usually seal the deal. But when some bee I haven't seen be(e)fore drops by, you can bet there's a flurry of activity. Like the other day when I saw a small dark bee zipping around the White Indigoberry (Randia aculeata), which is in flower now and literally abuzz with activity, I became obsessed with getting a good picture. And it was a challenge. The bee was about the size of H. poeyi, but black with white hairs instead of yellow, and it had no pollen-collecting hairs on its legs as that halictid species does. For several minutes all I got were shadows, butt shots, and empty foliage that the bee had just vacated. Eventually, though, I managed to get a couple of shots that were good enough to post to bugguide.net in hopes of an ID. Here's a better shot than those, taken a day later:
Megachilid bee, subgenus Chelostomoides. Boca Raton, FL, May 13, 2015.

Megachilid bee, subgenus Chelostomoides. Boca Raton, FL, May 13, 2015.

The ID didn't take long at all. About 10 minutes after I posted the shots, I got a notice that they had been placed in the interesting category "Megachile Subgenus Chelostomoides." Four species are found in Florida, according to John Pascarella's incredible1 online resource Bees of Florida. According to the information there, the large (very large) group of bees in the Megachilidae can be characterized by the following general features:
Long-tongued bees, rectangular labrum that is longer than broad and broadly articulated to the clypeus (Michener 2000). Other features that help distinguish the Megachilidae in the Southeastern U.S. are the lack of a basitibial plate (except in Lithurgus), 2 submarginal cells in the wing with the second submarginal rather long. The metasomal sterna have scopa present except in the parasitic forms. The scopa typically found on the hind legs of other bees is absent.
Not being an expert in bee terminology, I find only the first and last of the above-listed characters to be useful (they have long tongues and they don't have pollen-gathering hairs on their legs). This group of bees is one I'd not heard of before, so I did a bit of research. It turns out this group is unlike many of the other megachilids of North America, which are commonly called "leafcutter bees," the members of the subgenus Chelostomoides do not cut leaves to line their nests (Oh, those misleading common names!). Instead, they use resin, mud, or other materials. Which of the four species found in Florida, or whether this is a new one, I doubt I'll be able to determine. If you bothered to click through to the page from Bees of Florida you probably noticed how many of the shots needed to confirm ID were extreme close-ups of dead vouchered specimens; not something I'm likely to do here. But it sure was fun to watch this little bee zipping around the shrubbery! References bugguide.net Michener, C. 2007. Bees of the World, 2nd ed. Baltimore, MD: Johns Hopkins UP. Pascarella, J. Bees of Florida. Online resource available at http://entnemdept.ifas.ufl.edu/hallg/melitto/intro.htm.