New backyard bug: Halictus poeyi
A few recent mornings have been slightly foggy, which is unusual for Boca. It makes the air a bit more calm, which increases the photographic opportunities immensely. Unfortunately, this condition rarely lasts long enough for me to get the kids off to day care; by the time I return, the fog has burned off and the wind has kicked up. Nevertheless, one recent foggy morning was so intriguing that I strapped Daniel into his kiddie backpack and went outside with a camera to have a look. And I was rewarded by the sight of a species of bee I hadn't yet encountered on the property. Here it is, covered in the morning dew, resting (sleeping?) on the leaf of one of the firebush plants I have in the front yard: Garfield falling asleep in his lasagna. The picture shows that this bee is attracted to dead/decaying vegetable matter; other users of bugguide have reported this behavior as well.) The bee in question is Halictus poeyi, a species of sweat bee in the family Halictidae. You might recall that recently I found the first representative of the halictid bee family in the yard, Agapostemon splendens. Now that I've found a second species, I thought it appropriate to do a bit more research on this family. I did not know what I was getting into. H. poeyi is "primitively eusocial," which means that the bee lives in colonies like the more "advanced" eusocial insects (ants, honeybees), but "workers" and "queens" look alike. (In technical terms that are well explained in this article, "primitively eusocial organisms show no morphological difference between reproductives and non-reproductives"). So species like this give us insight into the way eusociality developed in the insects, before the species developed morphological differences between castes.
TaxonomyHere is some basic information about the family that I found from the UF website:
Halictid bees are found worldwide, but are especially abundant in temperate regions. [...] In Florida, there are 44 species found within eight genera. These genera include: Sphecodes (10 spp. of parastic bees), Lasioglossum (17 spp.), Nomia (4 spp.), Agapostemon (2 spp.), Augochloropsis (3 spp.), Augochlora (1 sp.), Augochlorella (3 spp.) and Halictus (4 spp.) (Pascarella 2006). Most of these species are also common throughout the eastern United States.You should never get all your information from one source, whether in politics or taxonomy. The site above says 44 Florida species; John Pascarella's "Bees of Florida," which was used in preparing the above page, says there are 66 taxa of Halictidae in the state. (Taxa might include subspecies, whereas "species" means only full species, which might explain the discrepancy.) However many sweat bees there are in Florida, though, this particular species has had an interesting taxonomic history. It was first described by Count LePeletier in 1841 (Histoire naturelle des insectes: Hyménoptères, t. II) as Halictus poeyi, but many workers considered it to be the same species as H. ligatus, first described by Thomas Say in 1837 (Boston Journal of Natural History, 1(4)393-416, published posthumously). Recently, though, (as a result of this article from 1996) it regained full species status, because unlike H. ligatus, the population of H. poeyi in south Florida is "continuously brooded and multivoltine" (that is, they rear young year-round, with more than one generation per year). The paper was written after an experiment comparing two different behavioral populations of H. ligatus revealed something interesting.
We would like to comment on the unexpected nature of this discovery. Halictus ligatus is one of the most abundant and readily identifiable bees in North America. It certainly is known as a variable species, but this is not surprising given its large geographic range, encompassing a wide range of aridities and altitudes, as well as the additional complexities caused by allometric variation and size-based caste differentiation. Indeed, morphological variation in H. ligatus has been the subject of a Ph.D. thesis (Kirkton, 1968) and no obvious disjunction was detected. Although other species groups in the Halictini are well known as being taxonomically "difficult", there has never been any doubt that Halictus ligatus was a "good" species. It seems probable that such ease of identification has discouraged the critical examination which taxa that are "known" to be "difficult" receive. This situation appears to be not uncommon in bees (Packer and Taylor, submitted) and warrants investigation in other taxa. The original impetus for this study was the investigation of genetic variation between behavioral types. We found no evidence for any genetic differentiation across the behavioral boundary in Central Florida, where populations appear to be panmictic with high genetic identities. However, we did find evidence of species level differentiation much further north. We now need to investigate whether behavioral or phenological differences exist between the two species in areas of sympatry.
Conservation ValueOne of the reasons I'm interested in native pollinators is because of their importance to native plants, and via that entree, to birds and other native fauna. Theodore Mitchell emphasized the conservation value of the native bee fauna back in 1960:
The native bee fauna probably is much more important than the honey bee in the conservation of wi!d life and game management, even though many wild colonics of honey bees occur in most wooded areas. Game birds, such as quail and turkey, the song birds, and many of the mammals depend to a considerable extent upon the fruits of various native plants, and such plants have a much closer ecological relationship to the native bee fauna than have most crop plants.