Butterflies Flying in Pennsylvania in May (60 Species)

60 butterflies were recorded flying in Pennsylvania in May in our iNaturalist sample; 4 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.

Mar Apr May Jun Jul Aug Sep Oct Nov

Top butterflies in May

Eastern Tiger Swallowtail728 obs.

Zabulon Skipper698 obs.

Red Admiral497 obs.

Spicebush Swallowtail464 obs.

Pearl Crescent374 obs.

Silver-spotted Skipper368 obs.

Small White292 obs.

Eastern Tailed-Blue276 obs.

Little Wood Satyr275 obs.

Black Swallowtail260 obs.

American Lady223 obs.

Juvenal's Duskywing221 obs.

All butterflies flying in Pennsylvania in May

#	Species	Scientific name	Family	Obs.	Peak in state
1	Eastern Tiger Swallowtail	Papilio glaucus	Swallowtails and Parnassians	728	Jul (rising)
2	Zabulon Skipper	Lon zabulon	Skippers	698	Aug (rising)
3	Red Admiral	Vanessa atalanta	Brush-footed Butterflies	497	Jul (rising)
4	Spicebush Swallowtail	Papilio troilus	Swallowtails and Parnassians	464	Aug (rising)
5	Pearl Crescent	Phyciodes tharos	Brush-footed Butterflies	374	Aug (rising)
6	Silver-spotted Skipper	Epargyreus clarus	Skippers	368	Aug (rising)
7	Small White	Pieris rapae	Whites, Yellows, and Sulphurs	292	Jul (rising)
8	Eastern Tailed-Blue	Everes comyntas	Gossamer-winged Butterflies	276	Aug (rising)
9	Little Wood Satyr	Megisto cymela	Brush-footed Butterflies	275	Jun (rising)
10	Black Swallowtail	Papilio polyxenes	Swallowtails and Parnassians	260	Aug (rising)
11	American Lady	Vanessa virginiensis	Brush-footed Butterflies	223	Jul (rising)
12	Juvenal's Duskywing	Erynnis juvenalis	Skippers	221	May (peak)
13	Hobomok Skipper	Lon hobomok	Skippers	199	Jun (rising)
14	Red-banded Hairstreak	Calycopis cecrops	Gossamer-winged Butterflies	157	Aug (rising)
15	Peck's Skipper	Polites peckius	Skippers	141	Aug (rising)
16	Mourning Cloak	Nymphalis antiopa	Brush-footed Butterflies	136	Apr (past peak)
17	Question Mark	Polygonia interrogationis	Brush-footed Butterflies	131	Jul (rising)
18	Eastern Comma	Polygonia comma	Brush-footed Butterflies	123	Aug (rising)
19	Red-spotted Admiral	Limenitis arthemis	Brush-footed Butterflies	110	Aug (rising)
20	Monarch	Danaus plexippus	Brush-footed Butterflies	107	Aug (rising)
21	Huron Skipper	Atalopedes huron	Skippers	89	Sep (rising)
22	Summer Azure	Celastrina neglecta	Gossamer-winged Butterflies	83	Jul (rising)
23	Meadow Fritillary	Boloria bellona	Brush-footed Butterflies	80	Aug (rising)
24	Wild Indigo Duskywing	Erynnis baptisiae	Skippers	68	Aug (rising)
25	American Copper	Lycaena hypophlaeas	Gossamer-winged Butterflies	66	Jul (rising)
26	Dreamy Duskywing	Erynnis icelus	Skippers	62	May (peak)
27	Baltimore Checkerspot	Euphydryas phaeton	Brush-footed Butterflies	54	Jun (rising)
28	Common Ringlet	Coenonympha california	Brush-footed Butterflies	48	Jun (rising)
29	Zebra Swallowtail	Eurytides marcellus	Swallowtails and Parnassians	47	Jul (rising)
30	Silvery Checkerspot	Chlosyne nycteis	Brush-footed Butterflies	44	Aug (rising)
31	Least Skipper	Ancyloxypha numitor	Skippers	39	Aug (rising)
32	Eastern Pine Elfin	Callophrys niphon	Gossamer-winged Butterflies	39	May (peak)
33	Harvester	Feniseca tarquinius	Gossamer-winged Butterflies	38	Jul (rising)
34	Painted Lady	Vanessa cardui	Brush-footed Butterflies	36	Aug (rising)
35	Pipevine Swallowtail	Battus philenor	Swallowtails and Parnassians	36	Jul (rising)
36	Viceroy	Limenitis archippus	Brush-footed Butterflies	36	Sep (rising)
37	Great Spangled Fritillary	Argynnis cybele	Brush-footed Butterflies	32	Jul (rising)
38	Orange Sulphur	Colias eurytheme	Whites, Yellows, and Sulphurs	25	Aug (rising)
39	Sleepy Duskywing	Erynnis brizo	Skippers	24	Apr (past peak)
40	Clouded Sulphur	Colias philodice	Whites, Yellows, and Sulphurs	21	Aug (rising)
41	Juniper Hairstreak	Callophrys gryneus	Gossamer-winged Butterflies	21	Jul (rising)
42	Eastern Giant Swallowtail	Heraclides cresphontes	Swallowtails and Parnassians	19	Aug (rising)
43	Falcate Orangetip	Anthocharis midea	Whites, Yellows, and Sulphurs	17	Apr (past peak)
44	Brown Elfin	Callophrys augustinus	Gossamer-winged Butterflies	15	May (peak)
45	Common Sootywing	Pholisora catullus	Skippers	11	Aug (rising)
46	Tawny-edged Skipper	Polites themistocles	Skippers	11	Aug (rising)
47	White M Hairstreak	Parrhasius m-album	Gossamer-winged Butterflies	11	Aug (rising)
48	Northern Pearly-eye	Lethe anthedon	Brush-footed Butterflies	11	Jul (rising)
49	Common Checkered-Skipper	Burnsius communis	Skippers	11	Sep (rising)
50	Gray Comma	Polygonia progne	Brush-footed Butterflies	9	Jun (rising)