July 12, 2016

Digger Bees and the Beardtongue

The foxglove beardtongue (Penstemon digitalis) is an early summer favorite of the fast flying and long tongued digger bees (Anthophora spp.). This bee is easier to hear than to see, producing a loud buzzing noise as it zigs, zags and zips among the white blossoms. The best chance to get a good glimpse of this honey bee sized insect is when they pause to hover in front of the flower, with their long tongue extended. Often times, they dive into the flower to get a sip of nectar, with only their abdomen visible.

Digger bees have very long tongues making then effective pollinators of beardtongue flowers.

Their scientific name Anthophora is Greek for “flower-bearer”. A fitting title for this very effective pollinator of tubular flowers like the beardtongue. After these blossoms fade away in late June the bees can be found frequenting the wild monarda and jewelweed. Only 5 species of digger bees are found in New York State and though one of the lesser known bees, they are an effective and efficient pollinator of native plants like the beardtongue.

Notice the orange hairs on the the abdomen of this Anthophora terminals.

Notice the orange hairs on the the abdomen of this Anthophora terminalis.

Most digger bees as their name suggest dig nesting chambers underground but Anthophora terminalis* is an exception to the rule building their nests in pithy stems or rotten wood. Like all solitary bees, every female is an egg layer. The female digger collects pollen on her hind legs to bring back to the brood chamber providing a protein rich provision for growing larvae.

*note the orange hairs on the tip of the abdomen.

Here a digger bee rests to groom herself of pollen.

Digger bees are just one of many pollinators that enjoy the native foxglove beardtongue. Among bees the flowers are also enjoyed by green sweat bees, small carpenters bees, bumble bees and a variety of mason bees. Butterflies and moths are lured in by the sweet nectar rewards including skippers and hummingbird moths.

A hummingbird moth visiting beardtongue

Visual Guide to the Visitors of Beardtongue…

A few minutes of observation among a field of beardtongue reveals that this is one of the popular flowers of summer. Instantly, you will be entertained by the acrobatics of the digger bee or the myriad other pollinators busy at work.