Four Imperiled Pollinators

—by Roxy Bergeron

Okay. I’ll say it. Our friends in the insect world are not all that, well, cuddly. Even though fascinating butterflies and tasty lobsters are insects, and the buzzin’ bees and other nectar- and pollen-seeking wingsters are crucial fertilizers of countless plants, the existence of a multitude of creatures who buzz, flutter, hop, creep, crawl, or swim around sans vertebrae in the biosphere is all too often considered dispensable.

Pesticides, weed killers, cut-backs, mow-downs, development, climate change, and countless human actions have long threatened species where they naturally live and thrive. Nature has a way of shifting right when humans shift left, such as resistance to chemicals that evolves in some species that keeps them ahead in the perpetual take-down control game. But all too often Nature proves too fragile to have the last word.

Luckily, creatures who navigate the world without a backbone have a special friend in the Xerces Society, a nonprofit organization based out of Portland dedicated to the preservation, health, and well-being of the invertebrate world.

As part of its education and outreach mission, the Xerces Society compiles “Red Lists” that catalog struggling invertebrates. These four pollinators found in Minnesota have been identified by Xerces as being in the cross-hairs of extinction. Here are their stories.

A bee with bling: rusty patched bumble bee1

From a range that once ran due west of Minnesota all the way to the Atlantic Ocean, from the Great Lakes to the Deep South, Bombus affinis has now all but vanished. This black-and-yellow pollinator actually looks like a couple of other bumble bee types, but to the expert apiarian eye, their subtle differences are apparent (if you can get one to stay still long enough!). The first abdominal segment and the rear half of second abdominal segment are yellow. Twin tufts of rusty fuzz are centered on their upper back—hence their common name—on the second abdominal segment. The remaining segments on their business end arusty patched bumble beere black, as is their head. (Queens do not sport the rusty patches.)

Bumble bees such as B. affinis engage in a curious behavior known as “buzz pollination.” Like a fuzzy flamenco dancer with a rose between the teeth, a bee will clench the flower’s pollen stalk in her jaws, then vibrate her wings to shake loose any recalcitrant pollen. Tomatoes, cranberries, and peppers are among the thousands of plants dependent upon this shimmy-shake of bumble bees.

Last year, the Xerces Society submitted a petition requesting that B. affinis be added to the list of protected endangered species.2 But their submittal, sent on January 31, 2013, to then-Secretary of the Interior Ken Salazar, has gone unanswered.

On February 13, 2014, the society, together with the Natural Resources Defense Council, sent a three-page letter to the current Secretary of the Interior, Sally Jewell, formally reminding her of the department’s legal obligations and expressing its willingness to pursue the matter legally.3

A pollinating pompom: yellowbanded bumble bee4

yellowbanded bumble beeBombus terricola, with its fuzzy black bottom, a faceful of yellow hair, and a tell-tale belt of brownish-yellow, is also on the Xerces Red List. Its range once covered real estate in the upper Midwest from southern Canada to Tennessee, and from the east side of the Rockies to the Maine coastline.

A border crosser comfortable flying in low levels of light and in cooler temperatures, it pollinates potatoes, alfalfa, cranberries, lots of wildflowers, rose-family plants such as raspberries, and other crops. Imagine its root-beer wings folded back as it feeds, lazily buzzing around, gathering pollen into its pollen-basket back-leg saddlebags.

The plight of this bumble bee species mirrors that of B. affinis. Both bees are imperiled by diseases as well as inbreeding due to isolated and decreasing populations, alterations to their habitats through agricultural and urban development, livestock grazing of the flowers the bees need for food, and the disturbance of their underground nest sites.

It is theorized that the decimation of these and other bumble bee species is linked to exposure to a foreign microbe (a parasitic gut fungus) transmitted to wild populations from commercial stock propagated in Europe.

Mother Nature’s eyelids: Karner blue butterfly5,6,7

Karner blue butterflyPrized by collectors, this gorgeous little butterfly, Lycaeides melissa samuelis, looks as if it lifted up off the canvas of a Monet painting. With a wing span just an inch wide, the males show delicate, luminous soft purple wings lined first by black then by white.

The female holds this violet shade at the center of the tops of her wings, where it fades into a brown-gray shade. She’s a bit more showy, with the rear of her upper wings serving as pallets for curious, irregularly-appearing orange oval markings.

The underside of the wings of either sex are gray undercarriages dotted with black spots and a mesmerizing curve of loping orange crescents moving around the outside edge of each wing.

Their specialized habit of laying their eggs only on the leaves of wild blue lupines leads them to seek out sunny patches found within an oak savanna or pine barrens, or the sandy environs of some lakeshore dunes. This species hatches out in spring, breeds, then hatches out once more to lay next year’s eggs each summer.

During their life span (a few days to a few weeks), they feast on the nectar from plants such as butterflyweed, blazing stars, and leafy spurge. The pollen that clings to their fuzzy bodies gives them the distinction of being a pollinator.

The Karner blue has been protected under the Endangered Species Act since 1992, endangered from intense collection and habitat loss. Wisconsin holds the most allure for these imperiled jewels, but they find cozy nurseries here in Minnesota as well as Indiana, Michigan, Ohio, New York, and New Hampshire, where they were first collected in the 1800s.

Various zoo propagation and reintroduction programs as well as the Wisconsin Habitat Conservation Program are helping restore this brilliant work of natural art.

Fair Isle flutterer: Persius duskywing8,9,10,11

Persius duskywingThis little incher of a butterfly is actually a “skipper”—a type of butterfly that flits and darts around, rather than exhibiting the smooth-move glide of “true” butterflies.
Xerces has red-listed a variety of this butterfly, the subspecies Erynnis persius persius. The E. persius’ home range spans from coast to coast, but its numbers here on the eastern side are compromised by natural landscape disruption and gypsy moth pesticide spraying.

The color of its wings reflects a pallet of earth tones, blended like the wooly strands of a Fair Isle knitted sweater, with shades of brown and muted greens and silvers and pinks and swipes of white near the bottoms of their wings. They sport little crochet hooks for antennae.

One generation a year is all they allow us to enjoy. Their caterpillars are precocious designers, making little covered hammocks by spinning silk to join leaves together, where they rest unseen between mealtimes.

The grown-ups prefer being on the ground and will come in for a landing, then open their wings wide and press them against the earth. (So watch where you step!)

They make their homes in the same kinds of areas as the Karner blues. Can’t you just see the rich browns and violets dancing about in the dappled barren of an oak savanna? Makes you yearn for summer.....

The only known Minnesota colony of E. persius is in Winona County, southeast of the Twin Cities. Theirs is an isolated kingdom here in the North Star State, and their solitary spot lends danger enough.

Luckily, as a species they are drafting off the powerful work being done to stabilize the Karner blue populations in Wisconsin, so their dusky cohorts across the Big Muddy may be able to secure the family tree should our little collective come to a sorry end.

Additional reading on the Karner blue

The brilliant writer Vladimir Nabokov was a master lepidopterist and is credited with being the first to definitively catalog and name the Karner blue, also known as Nabokov’s blue: http://www.nytimes.com/2000/07/14/arts/chasing-nabokov-s-elusive-and-end...

A fact sheet on the Karner blue: http://www.karnerblue.org/KarnerBlue_FactSheet.html

About the Xerces Society

A small blue butterfly—the Xerces blue, which went extinct in the 1940s when development eradicated it from the sand dunes of its San Francisco Peninsula habitat—was the inspiration for the name of the organization.12

Since 1971, this nonprofit has engaged the public and the legal system in its mission to preserve the habitat and existence of invertebrates. It publishes essays biannually in its Wings: Essays on Invertebrate Conservation magazine, which is free to members. You can sign up for their newsletter by going to http://www.xerces.org.

Article references
1. http://www.xerces.org/rusty-patched-bumble-bee
2. http://www.xerces.org/wp-content/uploads/2013/01/Bombus-affinis-petition...
3. http://www.xerces.org/2014/02/13/conservation-groups-threaten-lawsuit-to...
4. http://www.xerces.org/yellow-banded-bumble-bee
5. http://www.xerces.org/karner-blue
6. http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selecte...
7. http://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/kar...
8. http://www.xerces.org/persius-duskywing/
9. http://www.butterfliesofamerica.com/L/erynnis_p_persius_live.htm
10. http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selecte...
11. http://dnr.wi.gov/topic/EndangeredResources/SpeciesPhotos.asp?SpecCode=I...
12. http://www.xerces.org/story

[Roxy Bergeron is a volunteer cashier who regularly contributes newsletter articles exploring the intersection of the natural world and the actions of humankind.]