Wild Columbine & Ruby-throated Hummingbirds
Wild Columbine (Aquilegia canadensis) is in full flower, and its design and color beckon to a recently-returned migrant that is attracted to red as well as tubular flowers – the Ruby-throated Hummingbird. Not only does the flowering of Wild Columbine coincide with the arrival of hummingbirds in May, but the ranges of these two species are much the same. Wild Columbine’s five petals are in the shape of spurs, the tips of which contain nectar. Only hummingbirds and long-tongued bees can reach the nectar, and thus are its primary pollinators (there is a short-tongued bumblebee that tears open the tip of the spur in order to reach the nectar). While the hummingbird hovers beneath the flower and drinks nectar, its head rubs against Columbine’s long anthers, and the resulting pollen on the hummingbird’s head is brushed off onto the long styles of the next (Columbine) flower it visits, thereby pollinating it.
Hepatica Blooming
Hepatica has finally opened its hairy buds and greeted the world with its beautiful white, pink, blue and lavender blossoms. Typically the only wildflowers to appear earlier than this member of the Buttercup family are skunk cabbage and coltsfoot. Like many flowers, hepatica blossoms open on sunny days, and close at night and on cloudy days. This prevents rain from washing out the pollen and nectar which help attract pollinating insects, including early-flying bees and flies.
Bottle Gentian & Bumblebees
Bumblebees are nothing if not perseverant. Prying Bottle Gentian’s (Gentiana andrewsii) petals open is a monumental task, and one that few insects, other than large species of bumblebees, attempt — much less accomplish. The relationship of bumblebees and Bottle Gentian is an example of a mutualistic association — the bees benefit by having exclusive access to a bountiful and sugary nectar supply, and the plants benefit by attracting “loyal” pollinators that improve the chances for cross pollination.
Leafcutter Bee Cell Leaf Sections
At the risk of boring readers, I wanted to include one final Leafcutter Bee post, showing the two basic shapes that these bees chew out of leaves in order to make their incubator/nursery cells. There are oblong pieces, roughly an inch long, as well as perfectly round, ¼-inch diameter pieces. Each cell consists of several layers of oblong pieces rolled lengthwise which are sealed at one end with a round piece of leaf. The round end pieces appear to be glued into place (perhaps with the pollen/nectar mixture?) at one end of the cell, leaving the opposite end open. The cells are arranged end-to-end, with the open end of the cell placed against the sealed end of the next cell. Together they form a nest that is somewhat cigar-shaped and is typically located a few inches down in the soil, or in a cavity.
Leafcutter Bee Cell
Congratulations to those who recognized yesterday’s Mystery Photo! The tiny green cells are made from the leaves of almost any deciduous trees, and are cut and folded by leafcutter bees (Megachile genus). These solitary bees are about the size of a honeybee, but are much darker, almost black. They construct cigar-like nests (often in soil, holes in wood made by other insects, or plant stems) that contain several cells. After gathering and storing a ball, or loaf, of pollen inside the cell, the bee lays an egg and seals the cell shut. When the egg hatches, the larval bee feeds on the pollen and eventually spins a cocoon and pupates within it. An adult bee emerges from the cocoon and usually overwinters inside the cell. In the spring the bee chews its way out of the cell. Leafcutter bees pollinate wildflowers, fruits and vegetables and are also used as pollinators by commercial growers of blueberries, onions, carrots and alfalfa. (Photo submitted by Jan Gendreau.)
Spring Beauty Pollinators
Spring Beauty (Claytonia virginica) is one of our earliest woodland wildflowers to blossom, and thus an important source of nectar and pollen for the earliest foraging insects. Pink lines (“bee guides”) on each of its five petals lead pollinators to the center of the flower, where the nectar is located. The pollinator in this image, Andrena erigeniae, is one of the more common species of bees that visits Spring Beauty in the early spring. Notice the slightly pink pollen she has gathered into the pollen basket on her hind leg. If you’re interested in spending time observing the series of different insect pollinators that visit Spring Beauty as the season progresses, there’s a golden opportunity for you. If you go to http://springbeauties.wordpress.com/ you can participate as a citizen scientist volunteer and participate in their survey.
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