I've been reviewing the photos on my old Mac mini, since supplanted as my workhorse computer by the laptop. But I haven't transferred the nearly 2TB of photos from it, and inevitably I missed a few. Here are a couple from last November that begin with the letter A.As usual, click the photos for a larger image.
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: Megachile petulans, the leafcutter bee with the big head and stout abdomen, loves to appear on my patches of Dune Sunflower (Helianthus debilis): Halictus poeyi is the small bee with the low profile: Coelioxys dolichos, the cuckoo bee (the "common" name is Carpenter-mimic cuckoo leaf-cutter), looks pretty wicked: 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: 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.
...and the bees are buzzing with excitement. I was out in the yard at lunchtime, as usual, and I noticed more than the usual activity around the flowerbeds in front. There were these little yellow blurs zipping from flower to flower in the Gaillardia1. These are among the prettiest flowers in south Florida, although I must be honest, beauty is in the eye of the beholder. When I brought my native plant book to my son's preschool to show to the director, one of the native Floridians who had been there for decades burst out "that's a weed!" To which my response was "what better type of flower to plant in an area with lots of preschoolers than a weedy, hardy, one?" It didn't carry the day, though, and there are no beautiful Indian Blanketflower plantings at the preschool. Oh, well. Sure is ugly, right? Where was I? Oh, right. Out in the front yard, trying to figure out what these little yellow blips were. There were at least two, but I was never able to focus on them long enough for a picture. They would zip crazily along their patrol beat, skipping from flower to flower, alighting ever so briefly to find it empty and move on before I could so much as twitch my shutter finger. I wound up turning in circles trying to draw a bead on one of them but had to give it up after a few futile attempts. Soon, though, I noticed a much calmer, green-colored blip that resolved into a bee digging for pollen all across these little plants. You can see how successful she's been by how puffy and yellow her legs are: She was working hard, keeping her head down and doing her best to ignore that little yellow blip buzzing around, but after a while it became impossible: as soon as one of the blips noticed her, it plunged down at her and appeared to be trying to carry her off! Earlier I had been trying to figure out whether these yellow guys were some sort of robber fly or hunting wasp, but this interaction narrowed down the possibilities enormously: it must have been either territorial aggression or an attempt to get down to business. A minute or two later when one of the yellow blips finally settled on one of the flowers, perhaps to rest and reconnoiter a little bit, I was able to suss it out to my satisfaction. I zoomed in with my lens (not literally, of course, since it's a fixed focal length macro, but...) to reveal this: The attacker was none other than a male A. splendens looking to, ahem, get busy. I wasn't able to get pictures of any of the attacks, but this node over at bugguide.net should give you an idea of the general nature of the proceedings, should you care to follow the link. Kudos to photographer Tim Lethbridge for that work! I'm surprised, in retrospect, by how yellow the blips of the male bees on their patrol flights appeared; their thorax looks green in the pictures. I think, though, that it must give off a bit of a gold highlight which, combined with the yellow and black stripes on the abdomen as opposed to the green and black of the female, is probably responsible for the great difference in GISS. According to Eric Grissell (2010: 220), sweat bees are "the most behaviorally complex of all the so-called solitary bees, ranging from solitary to communal, semisocial, and primitively eusocial." Grissell provides some good information for the amateur taxonomist as well: the term "sweat bee" is a bit of a simplification, since this family includes entire groups of bees that aren't all that interested in alighting on our arms and trying to drink up our sweat. (Although to be fair, many bees in the genus Lasioglossum reportedly do exhibit this behavior, although I've not witnessed it personally.) He calls the bees in the genera Augochlorella, Augochlora, and Agapostemon " 'little green bees' because they have no common name and they are little and green." I also have to give props to the Xerces Society for the accuracy of their description of the genus: "a fast-moving metallic green blur over summer flowers is probably an Agapostemon." These bees are generally solitary nesters in bare soil, so it's important to remember to leave some bare patches here and there if you want to encourage them. References Grissell, E. (2010). Bees, Wasps, and Ants: The Indispensable Role of Hymenoptera in the Garden. Portland: Timber Press. Mader, E., Shephard, M., Vaughan, M., Black, S., and LeBuhn, G. (2011). The Xerces Society Guide to Attracting Native Pollinators: Protecting North America's Bees and Butterflies. North Adams, MA: Storey.
Sweat bees are fairly common. We get two kinds here in my yard, neither of which are common enough to have common names, but which I see fairly frequently: Agapostemon splendens and Halictus poeyi. The "splendid" green Agapostemon moves very quickly; a good shot of it is fairly rare. But H. poeyi is a bit more sedate, allowing for some decent portraits. Here are a few. From a post in 2012:
If you're a native plant gardener, it's easy to let your focus on native plants and animals blind you to the characteristics of non-native species. But one of the most important non-native species worldwide is the honey bee, Apis mellifera. Because they're so common, I frequently opt not to take pictures of them, preferring instead the more unusual "sweat bees" (halictids), with their bright green bodies and unpredictable (to me at least) sighting opportunities. This gal, for instance, was rescued from drowning in my backyard pool; she's still in the net (she recovered and flew away):But honey bees are in my yard each and every day, from the first glimmer of gray in the early morning to the last fading bit of the gloaming after sunset. And they're pretty amazing creatures in their own right. They pollinate much of the country's food supply, which I think is just lovely (I love to eat!). They make honey, which I think is delicious (I love to eat!). And they pollinate the clover in the cow paddies of the Midwest that some few lucky cows that aren't part of the industrial feedlot supply get to munch on. (Did I mention that I love to eat?) I knew that bees were declining, due, it is suspected, to use (mis- or over-, I'm not sure) of neonicotinoid pesticides to control harmful insects on our monoculture food crops. Unfortunately, these systemic insecticides don't discriminate: they kill the bad (pests) and the good (pollinators) alike! I also knew that bees work pretty hard (they work my yard much longer than I do, but I try not to feel too bad about it: 'm just one person; they are a multitude, and that IS their day job). What I absolutely never knew about honey bees, though, is that they have hairy eyes: In the picture above you can see the hairs that arise from the spots where the facets of the compound eye meet. It's a bit unclear to me whether these come from EVERY intersection or just some of them; the micro photos I've seen are split on the issue. In this amazing scanning electron microscope (SEM) image of a honeybee's eye, there are hairs at what look like random intersections of ommatidia (the individual facets that make up the compound eye): In that shot, which appeared in Rose-Lynn Fisher's 2010 Bee, you can clearly see that not every facet junction has a hair growing out of it. But in this random shot from the interwebs (source citation needed), which admittedly doesn't show all the junctions as clearly, it looks like there's a lot more hair: So which is it? According to the beekeeper and blogger whose site I first saw the above image on, "These hairs are believed to detect wind direction and allow the bees to stay on course in windy conditions. When these hairs were removed from bees in a 1965 experiment, the bees could no longer find their feeding sites." I'll have to source that study. I don't really know the answer, but I love to have a new question to track down. And that's one of the great things about turning your (and your camera's) eye to the simple things: you can always find new questions! I suspect that the relative abundance of hairs at ommatidial intersections is largely a question of the area of the eye in question and the angle from which the photograph is taken. Here's another shot by Rose-Lynn Fisher, again from that incredible book about bees; it seems to show many more hairs than the first image, but near the margins of the eye, there are fewer hairs (makes sense, since they would crowd up against the hairs on the head if they grew thickly all the way to the edge: I do know that, unlike the honeybee, most bees (and their cousins, the wasps and ants) do NOT have hair growing out of their eyes. Here's a sweat bee from my yard: And here's a close-up of the eye from that image, where you can clearly see the lack of hair in the compound eye: And, because she has such pretty eyes, here's a close-up of Agapostemon splendens, the first bee in this post: So, what do you think? Do the eyes have it? (Groan all you want; it's my blog!)