Specialist Bees

Doug Tallamy has done a great job making lists of native plant genera that show the number of different caterpillar species each genus supports. Great, so now we all know to plant native oaks, cherries, willows, goldenrod, etc. But there is a lot more to supporting biodiversity than caterpillars. Take bees, for example. Of the roughly 4,000 or so native bees in the US and Canada, somewhere around 30% are pollen specialists that require pollen from just one or a few plant genera to provision their young (USGS). The specialists appear more threatened than the generalists according to common sense and several research papers. So what do we do to support pollen specialist bees? Where is the list of native plant genera that shows the number of specialist bees that use pollen from that genus? Jarrod Fowler has done extensive literature searches to create lists of plant genera that support specialist bees for the Eastern, Central, and Western US. Also, the National Wildlife Federation has a list that covers the Eastern US (including Tennessee) but many of those listed genera aren’t native to TN and in other cases support specialist bees that aren’t native to Tennessee.

So, how do we get a list for Tennessee? If you copy/paste Jarrod’s Central US table into your favorite spreadsheet, use spreadsheet functions to count the number of occurrences of  “TN” for each genus, and delete the genera that show a zero, you find there are 76 species of native specialist bees that utilize pollen from plants native to Tennessee, and here are their favorite genera.

Plant Genera and the Number of Specialist Bee Species Supported

Genus Common Name Family Number
Helianthus L. Sunflowers Asteraceae 19
Rudbeckia L. Coneflowers (Susans) Asteraceae 16
Solidago L. Goldenrods Asteraceae 14
Symphyotrichum Nees American Asters Asteraceae 11
Coreopsis L. Tickseeds Asteraceae 10
Grindelia Willd. Gumweeds Asteraceae 9
Verbesina L. Crownbeards Asteraceae 9
Bidens L. Beggarticks Asteraceae 8
Erigeron L. Fleabanes Asteraceae 7
Vaccinium L. Blueberries Ericaceae 7
Salix L. Willows Salicaceae 6
Silphium L. Rosinweeds Asteraceae 6
Vernonia Schreb. Ironweeds Asteraceae 6
Cirsium Mill. Thistles Asteraceae 5
Eurybia (Cass.) Cass. Wood Asters Asteraceae 5
Ratibida Raf. Prairie Coneflowers Asteraceae 5
Chrysopsis (Nutt.) Elliot Golden Asters Asteraceae 4
Heterotheca Cass. Golden Asters Asteraceae 4
Baccharis L. Salt Bushes Asteraceae 3
Gaillardia Foug. Blanket Flowers Asteraceae 3
Phacelia Juss. Scorpionweeds Boraginaceae 3
Potentilla L. Cinquefoils Rosaceae 3
Senecio L. Ragworts Asteraceae 3
Cornus (Swida) L. Dogwoods Cornaceae 2
Echinacea Moench Coneflowers Asteraceae 2
Euthamia Nutt. ex Cass. Goldentops Asteraceae 2
Fragaria L. Strawberries Rosaceae 2
Helenium L. Sneezeweeds Asteraceae 2
Heliopsis Pers. Early Sunflowers Asteraceae 2
Lyonia Nutt. Staggerbushes Ericaceae 2
Pyrrhopappus DC. Desert Chicories Asteraceae 2
Arabis L. Rockcresses Brassicaceae 1
Calystegia R. Br. Bindweeds Convolvulaceae 1
Cardamine L. Toothworts Brassicaceae 1
Ceanothus L. New Jersey Teas Rhamnaceae 1
Cercis L. Redbuds Fabaceae 1
Claytonia L. Spring Beauties Montiaceae 1
Cucurbita L. Squashes Cucurbiteae 1
Erythronium L. Trout Lilies Liliaceae 1
Gaylussacia Kunth Huckleberries Ericaceae 1
Geranium L. Cranesbills Geraniaceae 1
Heuchera L. Alumroots Sacifragaceae 1
Hibiscus L. Mallows Malvaceae 1
Hieracium L. Hawkweeds Asteraceae 1
Hydrophyllum L. Waterleafs Boraginaceae 1
Ilex L. Hollies Aquifoliaceae 1
Ipomoea L. Morning Glories Convolvulaceae 1
Krigia Schreb. Dwarf Dandelions Asteraceae 1
Lupinus L. Lupines Fabaceae 1
Lysimachia L. Loosestrifes Primulaceae 1
Monarda L. Bee Balms Lamiaceae 1
Nemophila Nutt. Baby Blue Eyes Boraginaceae 1
Oenothera L. Evening Primroses Onagraceae 1
Packera Á. Löve & D. Löve Groundsels Asteraceae 1
Penstemon Schmidel Beardtongues Plantagiinaceae 1
Physalis L. Groundcherries Solanaceae 1
Pityopsis Nutt. Silkgrasses Asteraceae 1
Rhododendron L. Rhododendrons Ericaceae 1
Rubus L. Blackberries Rosaceae 1
Viola L. Violets Violaceae 1
Waldsteinia Willd. Barren Strawberries Rosaceae 1
Zizia W.D.J. Koch Alexanders Apiaceae 1