Wednesday, December 10, 2025

Directory of neglected floral insect hosts and habitats in Vermont.

Index:

  • Table 1. Directory of neglected floral insect hosts and habitats in Vt. 
  • Table 2. Notes
  • Table 3. Individual Plants for Specialist Bees. 
  • Table 4. Bees that are not recorded in VT, but likely to be in VT. and their host plants.
  • Table 5. Biophysical regions of Vermont

2026 Goal: Produce more targeted documentation of insects on neglected floral hosts and habitats.

Month(s) to Observe (VT)

Host/Habitat (Genus / Group)

Host Value

iNat Coverage

Key Genera Supported (Vermont)

March–April

Salix spp. (Sandbar willow - Salix exigua and other Salix spp.) Native Willows are among the top insect-host genera in Vermont.

Very High

Very Low

Andrena, Colletes, Perdita, Osmia, Nomada (cleptoparasites). Hosts hundreds of moths, flies, beetles, and sawflies. Note: Salix interior blooms May - July, but the fairy bee only seems to be active late June - July

April

Populus spp. (aspens & poplars)

High

Low

Andrena, Osmia, Colletes, Nomada. Hosts many moth species + leaf miners.

April–May

Viola spp. (native woodland & wetland violets)

High

Low

Andrena, Colletes, Halictus, Small sweat bees (Lasioglossum), Masked bees (Hylaeus). Required hosts for fritillaries.

May–June

Bog / Fen shrubs: Vaccinium / Ericaceae (blueberries, cranberries, Deerberry, leatherleaf - Vaccinium, Chamaedaphne). Also consider commercial blueberry grower sites.

High / Very High

Very Low / Extremely Low

Andrena, Colletes, Osmia, Lasioglossum Halictus, Hylaeus. Hosts: Carex, Parnassia, orchids, calciphiles. Insects that are often absent elsewhere.

May–June

Lupinus (lupines, e.g., Lupinus perennis where present)



Andrena, Colletes, Eucera, Melitta (if present regionally)

May–June

Fabaceae - Native lupines & other natives (if present)



Andrena, Eucera, Colletes

May–July

Fabaceae (legumes broadly; e.g., Trifolium, native Lespedeza)



Andrena, Lasioglossum, Halictus, Bombus, Nomada

May–July

Carex and graminoids (sedges, rushes) - habitat focus.

Very High

Very Low

Lasioglossum, Halictus, Hylaeus, Andrena (indirect), Bombus (nesting/foraging landscape). Essential to skipper butterflies, moths, and leafhoppers.

June

Parnassia (grass-of-Parnassus - calcareous fen specialist)



Andrena, Colletes

June–July

Wetland forbs & fen calciphiles (various forbs)



Andrena, Colletes, Halictus

June–July (short season)

Boreal habitat (dwarf willows, alpine sedges, boreal forbs)



Andrena, Colletes, Bombus, Lasioglossum

July–August

Asteraceae - Cirsium (native thistles)



Andrena, Bombus, Osmia, Melissodes

July–August

Asteraceae - Helianthus (native sunflowers)



Protandrena, Andrena, Colletes, Melissodes

July–September

Powerline corridors & old fields (native composites & legumes)



Andrena, Bombus, Lasioglossum, Melissodes

August–September

Asteraceae - Solidago (goldenrods)



Andrena, Colletes, Perdita, Melissodes, Bombus, Epeolus (cleptoparasites)

August–September

Native Goldenrods & late composites (broad Asteraceae group)



Andrena, Colletes, Perdita, Melissodes, Bombus

September

Asteraceae - Symphyotrichum (asters)



Andrena, Colletes, Perdita, Bombus

?

Betula spp (Birches)

Moderate-high

Moderate

Strong moth and beetle associations.

?

Powerline fields

Moderate

Moderate

Can hold rare asters, legumes, grasses

?

Alpine plants

Moderate

Very Low

Very specialized insects

?

Native Shrubs (Non-showy): (Spiraea alba, Diervilla lonicera, Ceanothus americanus)

Moderate-high

Low

Support specialist moths & pollinators


Rich Hardwoods



Lots of fun bees on spring ephemerals

For Reference

Wetlands. Several wetland obligates (and many facultative wetland plants) are hosts to specialist bees. 



Specialist bees…


Month(s) to Observe (VT)

Host/Habitat (Genus / Group)

Contains Specialist Bee Species? (Y/N)

Notes (specialists, habitat, visitor type, source highlights)

March–April

Salix spp. (Sandbar willow - Salix exigua and other Salix spp.) Native Willows are among the top insect-host genera in Vermont.

Y

Willows are top early-season pollen hosts; many Andrena species oligolectic on Salix; Perdita maculigera recorded on sandbar willow in VT (val, Fowler & Droege).

April

Populus spp. (aspens & poplars)

Y

Early pollen source; some Andrena show Salicaceae preferences; impactful for early-season bees (VAL, Fowler). Common on landscape, uncommon on iNat.Populus is a minor but important early pollen source


April–May

Viola spp. (native woodland & wetland violets)

Y

Viola specialists (e.g., Andrena violae); lawn violets often mask forest violets (VAL, Fowler). Forest and wetland violets are especially missing.


May–June

Bog / Fen shrubs: Vaccinium / Ericaceae (blueberries, cranberries, Deerberry, leatherleaf - Vaccinium, Chamaedaphne). Also consider commercial blueberry grower sites.

Y

Ericaceae specialists known (Andrena spp., Colletes) and important in bog/heath habitats (Fowler, VAL). Hosts: Carex, Parnassia, orchids, calciphiles. Fen: Rarest VT habitat = highest specialization. Cranberries and Deerberry are each host to rare bees not yet recorded from Vermont.


May–June

Lupinus (lupines, e.g., Lupinus perennis where present)

Y

Lupine specialists exist (Perdita, Melitta in some regions); in VT presence limited—check local range (Native Plant Trust, Fowler)

May–June

Fabaceae - Native lupines & other natives (if present)

Y

Some specialist bees tied to Lupinus and other native legumes regionally; check local occurrences (Fowler, Native Plant Trust)

May–July

Fabaceae (legumes broadly; e.g., Trifolium, native Lespedeza)

N

Many legumes attract generalist bees; some fabaceae specialists exist regionally but fewer strict oligoleges in VT (various sources)

May–July

Carex and graminoids (sedges, rushes) - habitat focus.

N

Sedges provide structure and nesting microhabitat; not major pollen hosts but crucial for wetland ecosystems (VAL notes). Sedges: Backbone hosts for wetland & forest insects. Fen & forest sedges are especially missing in iNat postings.


June

Parnassia (grass-of-Parnassus - calcareous fen specialist)

Y

Fen specialist bees (Andrena parnassiae documented on Parnassia); very high conservation value (Fowler, VAL)

June–July

Wetland forbs & fen calciphiles (various forbs)

Y

Many fen plants host specialist Andrena species; note sensitive habitat access (Fowler, UMAINE guide)

June–July (short season)

Boreal habitat (dwarf willows, alpine sedges, boreal forbs)

Y

Boreal/alpine specialists present; high-latitude species and specialists tied to boreal flora (Vermont Atlas of Life, regional studies)

July–August

Asteraceae - Cirsium (native thistles)

Y

Native Cirsium attract specialists; avoid non-native invasive thistles note (Fowler, VAL)

July–August

Asteraceae - Helianthus (native sunflowers)

Y

Helianthus associated with specialist species per Fowler; important in open habitats

July–September

Powerline corridors & old fields (native composites & legumes)

N

Habitat type that concentrates floral resources; supports both generalists and specialists depending on flora present (UMaine guide)

August–September

Asteraceae - Solidago (goldenrods)

Y

Solidago hosts many specialist bees (one of top genera for specialists per Fowler)

August–September

Native Goldenrods & late composites (broad Asteraceae group)

Y

Asteraceae as a family hosts large numbers of specialist bee spp.; goldenrods especially important (Fowler)

September

Asteraceae - Symphyotrichum (asters)

Y

Late-season important pollen resources; specialists known (Fowler)

?

Betula spp (Birches)


Gray birch & paper birch under-posted

?

Powerline fields


Excellent insect diversity

?

Alpine plants


Extremely short season

?

Native Shrubs (Non-showy): (Spiraea alba, Diervilla lonicera, Ceanothus americanus)


Bloom briefly or inconspicuously

For Reference

Wetlands. Several wetland obligates (and many facultative wetland plants) are hosts to specialist bees. 


Several wetland obligates (and many facultative wetland plants) are hosts to specialist bees. Pickerelweed (Pontederia cordata) and Water Lilies (Family Nymphaeaceae) are both reported as host plants for rare and uncommon bee species - the Pickerelweed Longhorn (Melissodes apicatus) and Water-lily Sweat Bee (Lasioglossum nelumbonis) respectively. A number of other uncommon to rare bees appear to be associated with wetlands, but not particular flowers. The Nelumbo Masked Bee (Hylaeus nelumbonis), Ocean Grove Metallic-Sweat bee (Lasioglossum oceanicum), and several others appear to be confined to wetlands. Wooded wetlands contain unique plant-bee associations—for example, Winterberry (Ilex verticillata) and (Colletes banksi) and Sheep Laurel (Kalmia angustifolia) and Kalmia Miner Bee (Andrena kalmiae), as well as abundant standing dead wood, which is an important nesting resource for many bees.

For Reference

VT F&W Vermont Bird and Pollinator-Friendly Perennial Species List




The lists above are of targeted plants - insects on neglected floral hosts and habitats.


The list below is of Individual Plants for Specialist Bees. 
(There is some overlap with the target list above.)

Month(s) to Observe (VT)

Host/Habitat (Genus / Group)

Key Genera Supported (Vermont)

Contains Specialist Bee Species? (Y/N)

March–April

Willows

VCE Specialist Bees

Y

May-June

Shrubby Dogwoods (the Swida group)

VCE Specialist Bees

Y

Late May-June

He-Huckleberry (Lyonia), fond of wet forests and marshes, and found primarily in southwestern VT

VCE Specialist Bees

Y

Late June/July-Aug/Sept. L.T. June-Aug

Loosestrifes. So far most of the recent VT records have been associated with Fringed Loosestrife (L. ciliata), though Whorled Loosestrife (L. quadrifolia) and Swamp Candles (L. terrestris) are also used. It is unclear if the non-native Lysimachia species are of any value to these bees. 

VCE Specialist Bees: Loosestrife Bees (Genus Macropis).  They are unique in collecting oils from our native Loosestrifes (Genus Lysimachia)

Y

June-Oct

Thistle

VCE Specialist Bees

Y

June-Aug. Some through Sept/Oct

Clammy Ground Cherry (Physalis), also tomatillos and domesticated Ground Cherries 

VCE Specialist Bees

Y

June-Sept

Pickerelweed

VCE Specialist Bees

Y

July-Sept (Native), May-Sept (non native)

Bellflowers, native and non-native

VCE Specialist Bees

Y

Late July-Sept

Sunflowers

VCE Specialist Bees

Y

Late July-Sept/Oct

Goldenrod

VCE Specialist Bees

Y

Aug-Oct

Asters

VCE Specialist Bees

Y

See by plant below

VCE Plants hosting a single bee species. See individual plant species below.

VCE Plants hosting a single bee speciesSee individual plant species below.


March–April

Spring Beauty

Spring Beauty Mining Bee (Andrena erigeniae

Y

Mid-to-late April

Trout Lily

Trout-lily Mining Bee (Andrena erythronii)

Y

April–May

Toothworts

Mustard Miner Bee (Andrena arabis)

Y

April-May

Geranium

Cranesbill Miner (Andrena distans)

Y

Late April into May

Bellwort


Y

April-June

May have a preference for the blue violet species.

Violet Miner (Andrena violae)

Y

May-June

Rockcress

Mustard Miner Bee (Andrena arabis)

Y

May-June Some spp. July-Aug

Golden Alexander

Golden-Alexanders Mining Bee (Andrena ziziae)

Y

May/June - Fall

Appalachian Barren-Strawberry (Waldsteinia fragarioides) & Cinquefoils (Potentilla)

Andrena ziziaeformis

Y

Late May-July

Rhododendron

Azalea Mining Bee (Andrena cornelli)

Y

Early to mid June

Virginia Waterleaf

Waterleaf Mining Bee (Andrena geranii)

Y

June-October

Viper's-Buglosses (Genus Echium)

Viper's Bugloss Small-Mason (Hoplitis anthocopoides)

Y

June/July-Sept/Oct

Common evening-primrose 

Evening Primrose Sweat Bee (Lasioglossum oenotherae)

Y

June-July

American Chestnut


Y

June/July-Aug/Sept

Wild Bergamot

Beebalm Shortface (Dufourea monardae)

Y

Late June-July

Winter squash or Zucchini

Pruinose Squash Bee (Peponapis Pruinosa)

Y

Late June-July

Only known from a few sites in VT

Squash Longhorn-Cuckoo (Triepeolus remigatus)

Y

Late Aug-Sept

Fen Grass of Parnassus (Parnassia glauca). It is limited to fens.

Parnassia Miner (Andrena parnassiae)

Y



Bees that are not recorded in VT, but likely to be in VT.
Source: An Annotated Checklist of the Bees of Vermont with Conservation Status and Natural History Notes. NE Naturalist, Volume 32, Monograph 27, 2025.    - Hardy, Veit, Milam, Ascher, Sharp, et al

Bee

Host Plant (or host bee)

Common name 

Andrena (Trachandrena) rehni

Castanea dentata

American Chestnut

Andrena uvulariae

Uvularia grandiflora (plant seeds in spring), Uvularia sessilifolia, Uvularia perfoliata. 

merrybells or bellworts, include Large-flowered bellwort, Sessile-leaf bellwort, and Perfoliate bellwort. 

Perdita (Alloperdita) novaengliae

Lyonia ligustrina

He-Huckleberry, or maleberry

Habropoda laboriosa

Vaccinium

Blueberries

Epeoloides pilosulus

Cleptoparasite of Macropis spp./   (L. ciliata),(L. quadriflora), and (L. terrestris)

Macropis needs oils to feed their young, with common host plants including Fringed Loosestrife (L. ciliata), Prairie Loosestrife (L. quadriflora), and Swamp Candles (L. terrestris), though L. ciliata seems a key one in the East

Triepeolus obliterates

Associated with Melissodes apicatus (Pickerelweed Longhorn Bee). Plant host for host bee (M.a.) is Pontederia cordata 

Obliterated Longhorn-Cuckoo,(Pickerelweed)

Nomada rodecki

Cleptoparasite of Melitta spp.


Colletes productus

Lyonia ligustrina. Likely host of Epeolus inornatus

He-Huckleberry, or maleberry

Colletes validus

Vaccinium. Sand nesting, a lower Connecticut River Valley search is warranted. 

cranberry, blueberry, bilberry, lingonberry, and huckleberry.

Sphecodes banksii

Possibly a Cleptoparasite of Lasioglossum vierecki

L.v. is a generalist bee

Anthidium (Anthidium) florentinum

Wool carder bee: strong preferences for flowers in the Asteraceae (sunflower/daisy family), Lamiaceae (mint family), and Fabaceae (pea/bean family).


Pseudoanthidium (Pseudoanthidium) nanu

Wool carder bee: primarily uses flowers from the Asteraceae family (thistles, knapweeds, sunflowers, etc.) as food sources, including Arctium, Centaurea, Cirsium, Grindelia, Helianthus, Inula, and Onopordum. They also visit legumes like Lotus corniculatus and utilize various plant stems (like thistles, raspberry


Stelis (Dolichostelis) louisae

Presumed host: Megachile campanulae. Plant: Campanula

M.c. uses Bellflowers (Campanulaspecies), especially Tall Bellflower, for pollen, though it also visits other plants like Milkweeds, Goldenrods, Mallows, and Mountain Mints, and uses plant resins for nesting. 

Coelioxys (Paracoelioxys) funerarius

Cleptoparasitic on Megachile


Coelioxys (Xerocoelioxys) immaculatus

Likely associated with Megachile addenda


Chelostoma (Foveosmia) campanularum

Campanulaceae

Bellflower family

Osmia (Diceratosmia) conjuncta

Snail-nesting species.


Macropis (Macropis) ciliata

Yellow Loosestrife plants (genus Lysimachia) for vital floral oils and pollen to feed their young, with specific host plants including Fringed Loosestrife (L. ciliata), Swamp Loosestrife (L. terrestris), and Fourflower Loosestrife (L. quadrifolia), though they gather nectar from other flowers like Dogbanes (Apocynum). 


Melitta (Cilissa) americana

Cranberry Specialist


Melitta (cilissa) eickworti

Vaccinium stamineum L. 

Deerberry



Biophysical regions of Vermont


Champlain Valley

Chittenden County (Northern Valley): Burlington, Colchester, Essex, Jericho, Milton, Shelburne, South Burlington, Williston, Winooski, St. George, Richmond, Westford. Addison County (Central/Southern Valley): Middlebury, Vergennes, Addison, Bridport, Bristol, Cornwall, Ferrisburgh, Leicester, Lincoln, Monkton, New Haven, Panton, Shoreham, Weybridge, Whiting. Grand Isle County (Islands): Alburgh, Grand Isle, Isle La Motte, North Hero, South Hero. Other Towns: Charlotte, Hinesburg, Starksboro, and areas near the lake, like Panton, Orwell, and parts of the Otter Creek flow. 

Champlain Hills

Covers hilly terrain between the Champlain Valley and Green Mountains, including towns like Underhill, Cambridge, Fletcher, Fairfax, and Westford

Taconic Mountain Vermont Valley

The Vermont Valley is a lowland region between the Taconic Mountains to the west and the Green Mountains to the east. Bennington: Located at the convergence of the Vermont Valley and the Walloomsac River valley. Manchester: Nestled in a valley between the Green and Taconic mountains. Pittsford (including the village of Florence): The valley floor generally falls within this biophysical region. Rutland (City and Town): Situated in a broad valley carved by Otter Creek, between the Green Mountains and the Taconic Range. The Taconic Mountains region runs parallel to the Vermont Valley to the west, extending from near Brandon in the north to the Massachusetts and New York borders in the south. Danby: The mountains broaden north of here, featuring prominent peaks. Dorset: Home to Dorset Mountain, one of the tallest peaks in the range. Hubbardton: Location of the Taconic Mountains Ramble State Park. Mendon: The area where Killington meets Chittenden and Mendon is near the Taconic range. Mount Tabor: The region extends south of Danby through here. Pawlet (specifically North Pawlet Hills): Features rounded, forested peaks in the northern Taconics. Poultney: The area around Lake St. Catherine here contains extensive slate quarries and is part of the range foothills. Sunderland: Chiselville village and Kelley Stand place are in this town located in the Taconic range. Tinmouth: Tinmouth Mountain overlooks the Valley of Vermont to the east of this town. Wells: The ridgeline of Saint Catherine Mountain is visible from here. 

Southern Green Mountains

The Southern Green Mountains biophysical area spans across parts of Bennington, Windham, Rutland, Windsor, and Addison counties: Andover, Arlington, Bennington, Brattleboro, Dorset, Gifford Woods (State Park in Sherburne, which is now incorporated into Killington), Jamaica, Killington (formerly Sherburne), Londonderry, Ludlow, Manchester, Mendon, Newfane, Plymouth, Pownall, Putney, Shrewsbury, Stratton, Townshend, Weston,   Wilmington 

Northern Green Mountains

Towns in Vermont's Northern Green Mountains region, often highlighted along the Green Mountain Byway, include Stowe, Waterbury, Cambridge, Hyde Park, Johnson, Morristown, Morrisville, Jeffersonville, and Waitsfield

Southern Vermont Piedmont

The Southern Vermont Piedmont (SP) covers towns in southeastern Vermont, characterized by rolling hills and river valleys, including areas around the Deerfield River, with key towns like Brattleboro, Dummerston, Putney, Newfane, Marlboro, Wilmington, Halifax, and parts of Bennington County.

Northern Vermont Piedmont

The Northern Vermont Piedmont (NP) covers central Vermont's rolling hills, including major towns like Montpelier, Barre, and surrounding areas contrasting with the mountains (Green Mountains/Champlain Valley), featuring diverse forests and rivers, with towns like Marshfield, Cabot, Wolcott, Eden, and parts of Berlin, East Montpelier, and Stowe fitting within its hilly landscape. 

Northeastern Highlands

The majority of towns in the Northeastern Highlands biophysical region of Vermont are located in the counties of Essex, Orleans, and Caledonia, a region often referred to as the Northeast Kingdom. The Victory Management Unit, which includes Victory Basin Wildlife Management Area and Victory State Forest, covers a large portion of the southern part of this region.  Averill, Bloomfield, Brighton (includes the village of Island Pond), Brunswick, Burke, Canaan, Charleston (eastern half is in this region), Concord, East Haven, Ferdinand, Granby, Guildhall, Kirby, Lemington, Lewis, Lunenburg, Lyndon (includes the village of Lyndonville), Maidstone, Morgan, Newark, Newport , Norton, Sheffield, Stannard, Sutton, Victory, Waterford, Westmore . 





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