Blister Beetles and Bumblebees
In the image above an orange Nemognatha punctulata LeConte feeds on a petal while two Pyrota lineata (striped blister beetles) appear to be mating. The striped beetles are native to Florida and common north of Polk County.
Late summer in Florida, when its too hot and too humid for most annuals to continue producing flowers, cosmos thrive. In my garden the cosmos population is entirely Cosmos sulphureus (orange cosmos). I've tried to introduce other cosmos over the years but only the C. sulphureus survive. These individuals are offspring from years of cultivation. I picked the original seeds from a garden in someone's yard as I was traveling to an appointment a decade ago. The flowers put on such a shocking display I had to stop and pick some of the seeds which quickly sprouted into my own stand of orange cosmos.
Adult Nemognatha punctulata LeConte, a blister beetle.
This year the flowers are attracting a strange and fascinating array of beetles. These beetles are largely blister beetles (Insecta: Coleoptera: Meloidae). The beetles move around sluggishly compared to the bumble bees that also visit these flowers every afternoon. As they fly in the beetles appear to be in slow motion, like little futuristic flying machines buzzing their way toward the next flower. Once on a flower they defend it while feeding on the flowers orange petals.
All of the social bumble bee species found in Florida range as far north as Canada. Bumble bees are easily recognized by the corbicula (pollen basket) on the hind tibiae in the females. Honey bees are the only other bees in Florida with this structure, but are easily recognized by their smaller size, hairy eyes, and lack of hind tibial spurs.
Large carpenter bees are often misidentified as bumble bees, but these are readily distinguished from bumble bees primarily due to the absence of pubescence on the dorsum of the carpenter bee abdomen, which is somewhat shiny.
There are a few species of bumblebees that are most common in Florida:
Bombus bimaculatus Cresson 1863, the twospotted bumble bee. Its range extends from Ontario to Maine, south to Florida, and west to Illinois, Kansas, Oklahoma, and Mississippi. Florida county records include Alachua, Clay, Franklin, Highlands, Lake, Levy, Marion, Okaloosa, and Orange.
Bombus fraternus (Smith) 1854, the southern plains bumble bee. Its range extends from New Jersey to Florida, and west to North and South Dakota, Nebraska, Colorado and New Mexico. Florida county records include Alachua, Franklin, Gadsden, Levy, Liberty, Orange, and St. Johns.
Bombus griseocollis (DeGeer) 1773, the brown-belted bumble bee. Its range extends from Quebec and Maine to Florida, and throughout the American West (DL 21011). Florida county records include Alachua, Clay, Collier, Highlands, Marion, and Osceola.
Bombus impatiens Cresson 1863, the common eastern bumble bee. This species is native from Ontario to Maine and south to Florida and was introduced in California and in British Columbia, Canada (EOL 2011). Florida county records include Alachua: Bradford, Calhoun, Escambia, Franklin, Jackson, Gadsden, Highlands, Levy, Liberty, Okaloosa, Orange, Palm Beach, Polk, and Santa Rosa.
Bombus pensylvanicus (DeGeer) 1773, the American bumble bee. Its range extends from Quebec and Ontario, Maryland south to Florida, then west to Minnesota, South Dakota, Nebraska, Colorado, New Mexico, and Mexico (Anonymous 2011). Florida county records include Alachua, Bradford, Collier, Escambia, Flagler, Highlands, Lake, Lee, Levy, Marion, Orange, Putnam, Sarasota, and Santa Rosa.
Bombus terricola Kirby 1837, the yellow-banded bumble bee. Originally, this species extended from Nova Scotia to Florida, west to British Columbia, Montana and South Dakota. While once common, it has declined dramatically since 1990 (Anonymous 2011). No specimens seen from Florida, but recorded from Florida by Mitchell (1962).