Butterflies Flying in Pennsylvania in October (57 Species)

57 butterflies were recorded flying in Pennsylvania in October in our iNaturalist sample; 2 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 October

Monarch805 obs.

Common Buckeye421 obs.

Small White421 obs.

Huron Skipper402 obs.

Variegated Fritillary394 obs.

Orange Sulphur262 obs.

Black Swallowtail224 obs.

Eastern Comma197 obs.

Fiery Skipper187 obs.

Painted Lady183 obs.

Pearl Crescent170 obs.

Common Checkered-Skipper148 obs.

All butterflies flying in Pennsylvania in October

#	Species	Scientific name	Family	Obs.	Peak in state
1	Monarch	Danaus plexippus	Brush-footed Butterflies	805	Aug (past peak)
2	Common Buckeye	Junonia coenia	Brush-footed Butterflies	421	Sep (past peak)
3	Small White	Pieris rapae	Whites, Yellows, and Sulphurs	421	Jul (past peak)
4	Huron Skipper	Atalopedes huron	Skippers	402	Sep (past peak)
5	Variegated Fritillary	Euptoieta claudia	Brush-footed Butterflies	394	Sep (past peak)
6	Orange Sulphur	Colias eurytheme	Whites, Yellows, and Sulphurs	262	Aug (past peak)
7	Black Swallowtail	Papilio polyxenes	Swallowtails and Parnassians	224	Aug (past peak)
8	Eastern Comma	Polygonia comma	Brush-footed Butterflies	197	Aug (past peak)
9	Fiery Skipper	Hylephila phyleus	Skippers	187	Oct (peak)
10	Painted Lady	Vanessa cardui	Brush-footed Butterflies	183	Aug (past peak)
11	Pearl Crescent	Phyciodes tharos	Brush-footed Butterflies	170	Aug (past peak)
12	Common Checkered-Skipper	Burnsius communis	Skippers	148	Sep (past peak)
13	Eastern Tailed-Blue	Everes comyntas	Gossamer-winged Butterflies	104	Aug (past peak)
14	Red-banded Hairstreak	Calycopis cecrops	Gossamer-winged Butterflies	93	Aug (past peak)
15	Silver-spotted Skipper	Epargyreus clarus	Skippers	73	Aug (past peak)
16	American Lady	Vanessa virginiensis	Brush-footed Butterflies	72	Jul (past peak)
17	Clouded Sulphur	Colias philodice	Whites, Yellows, and Sulphurs	72	Aug (past peak)
18	Eastern Tiger Swallowtail	Papilio glaucus	Swallowtails and Parnassians	67	Jul (past peak)
19	Spicebush Swallowtail	Papilio troilus	Swallowtails and Parnassians	62	Aug (past peak)
20	Meadow Fritillary	Boloria bellona	Brush-footed Butterflies	62	Aug (past peak)
21	Red Admiral	Vanessa atalanta	Brush-footed Butterflies	52	Jul (past peak)
22	Gray Hairstreak	Strymon melinus	Gossamer-winged Butterflies	51	Aug (past peak)
23	Question Mark	Polygonia interrogationis	Brush-footed Butterflies	46	Jul (past peak)
24	Peck's Skipper	Polites peckius	Skippers	43	Aug (past peak)
25	Cloudless Sulphur	Phoebis sennae	Whites, Yellows, and Sulphurs	33	Aug (past peak)
26	Mourning Cloak	Nymphalis antiopa	Brush-footed Butterflies	29	Apr (past peak)
27	Ocola Skipper	Panoquina ocola	Skippers	28	Oct (peak)
28	Red-spotted Admiral	Limenitis arthemis	Brush-footed Butterflies	27	Aug (past peak)
29	Great Spangled Fritillary	Argynnis cybele	Brush-footed Butterflies	27	Jul (past peak)
30	Sleepy Orange	Eurema nicippe	Whites, Yellows, and Sulphurs	26	Aug (past peak)
31	Wild Indigo Duskywing	Erynnis baptisiae	Skippers	24	Aug (past peak)
32	Bronze Copper	Tharsalea hyllus	Gossamer-winged Butterflies	24	Sep (past peak)
33	Pipevine Swallowtail	Battus philenor	Swallowtails and Parnassians	21	Jul (past peak)
34	American Copper	Lycaena hypophlaeas	Gossamer-winged Butterflies	18	Jul (past peak)
35	Viceroy	Limenitis archippus	Brush-footed Butterflies	15	Sep (past peak)
36	Zabulon Skipper	Lon zabulon	Skippers	14	Aug (past peak)
37	Least Skipper	Ancyloxypha numitor	Skippers	13	Aug (past peak)
38	Long-tailed Skipper	Urbanus proteus	Skippers	8	Sep (past peak)
39	Northern Pearly-eye	Lethe anthedon	Brush-footed Butterflies	8	Jul (past peak)
40	Horace's Duskywing	Erynnis horatius	Skippers	6	Jul (past peak)
41	Summer Azure	Celastrina neglecta	Gossamer-winged Butterflies	6	Jul (past peak)
42	White M Hairstreak	Parrhasius m-album	Gossamer-winged Butterflies	6	Aug (past peak)
43	Harvester	Feniseca tarquinius	Gossamer-winged Butterflies	5	Jul (past peak)
44	Eastern Giant Swallowtail	Heraclides cresphontes	Swallowtails and Parnassians	5	Aug (past peak)
45	Hackberry Emperor	Asterocampa celtis	Brush-footed Butterflies	4	Aug (past peak)
46	Milbert's Tortoiseshell	Aglais milberti	Brush-footed Butterflies	4	Jul (past peak)
47	Little Yellow	Eurema lisa	Whites, Yellows, and Sulphurs	3	Aug (past peak)
48	American Snout	Libytheana carinenta	Brush-footed Butterflies	3	Jul (past peak)
49	Tawny-edged Skipper	Polites themistocles	Skippers	2	Aug (past peak)
50	Northern Crescent	Phyciodes cocyta	Brush-footed Butterflies	2	Jul (past peak)