Cercis canadensis (Redbud)
(Bees suck nectar or collect pollen, while other insects suck nectar; butterflies, skippers, & beetles are non-pollinating; most observations are from Robertson, otherwise they are from Krombein et al. as indicated below)

Bees (long-tongued)
Apidae (Apinae): Apis mellifera sn cp fq; Apidae (Bombini): Bombus auricomus sn fq, Bombus griseocallis sn cp, Bombus impatiens sn, Bombus pensylvanica sn, Bombus vagans sn; Anthophoridae (Anthophorini): Anthophora ursina sn fq, Habropoda laboriosus sn; Anthophoridae (Ceratinini): Ceratina calcarata sn; Anthophoridae (Eucerini): Synhalonia belfragii sn, Synhalonia speciosa sn cp fq icp; Anthophoridae (Nomadini): Nomada affabilis sn, Nomada cuneatus sn, Nomada denticulata sn, Nomada luteola sn, Nomada sayi sn, Nomada sulphurata sn; Megachilidae (Osmiini): Osmia atriventris sn cp, Osmia bucephala bucephala sn cp, Osmia conjuncta sn cp, Osmia lignaria lignaria sn cp fq, Osmia pumila sn cp fq

Bees (short-tongued)
Halictidae (Halictinae): Agapostemon sericea sn, Augochlora purus purus sn, Augochlorella striata sn, Augochloropsis metallica metallica sn, Halictus confusus sn cp fq, Halictus rubicunda sn cp fq, Lasioglossum cinctipes sn, Lasioglossum coriaceus sn, Lasioglossum forbesii sn, Lasioglossum imitatus sn cp fq, Lasioglossum pilosus pilosus sn, Lasioglossum versatus sn cp fq, Lasioglossum zephyrus sn; Colletidae (Colletinae): Colletes inaequalis sn cp fq (Rb, Kr); Andrenidae (Andreninae): Andrena carlini sn cp (Rb, Kr), Andrena cressonii sn, Andrena forbesii (Kr), Andrena heraclei (Kr), Andrena hippotes (Kr), Andrena imitatrix imitatrix sn cp, Andrena mandibularis sn cp, Andrena sayi sn cp

Wasps
Vespidae: Polistes fuscata sn

Flies
Empididae: Empis otiosa sn fq, Empis pudica sn, Rhamphomyia priapulus sn; Bombyliidae: Bombylius major sn

Butterflies
Nymphalidae: Vanessa atalanta sn np, Vanessa virginiensis sn np; Lycaenidae: Everes comyntas sn np

Skippers
Hesperiidae: Erynnis icelus sn np, Erynnis juvenalis sn np

Beetles
Cerambycidae: Molorchus bimaculatus sn np