Butterflies Flying in Delaware in September (57 Species)

57 butterflies were recorded flying in Delaware in September in our iNaturalist sample; 16 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.

Apr May Jun Jul Aug Sep Oct Nov

Top butterflies in September

Monarch514 obs.

Huron Skipper466 obs.

Common Buckeye300 obs.

Eastern Tiger Swallowtail227 obs.

Variegated Fritillary193 obs.

Silver-spotted Skipper162 obs.

Pearl Crescent161 obs.

Eastern Tailed-Blue130 obs.

Small White129 obs.

Peck's Skipper114 obs.

Gray Hairstreak109 obs.

Red-banded Hairstreak80 obs.

All butterflies flying in Delaware in September

#	Species	Scientific name	Family	Obs.	Peak in state
1	Monarch	Danaus plexippus	Brush-footed Butterflies	514	Aug (past peak)
2	Huron Skipper	Atalopedes huron	Skippers	466	Sep (peak)
3	Common Buckeye	Junonia coenia	Brush-footed Butterflies	300	Sep (peak)
4	Eastern Tiger Swallowtail	Papilio glaucus	Swallowtails and Parnassians	227	Aug (past peak)
5	Variegated Fritillary	Euptoieta claudia	Brush-footed Butterflies	193	Sep (peak)
6	Silver-spotted Skipper	Epargyreus clarus	Skippers	162	Aug (past peak)
7	Pearl Crescent	Phyciodes tharos	Brush-footed Butterflies	161	Sep (peak)
8	Eastern Tailed-Blue	Everes comyntas	Gossamer-winged Butterflies	130	Sep (peak)
9	Small White	Pieris rapae	Whites, Yellows, and Sulphurs	129	Jun (past peak)
10	Peck's Skipper	Polites peckius	Skippers	114	Sep (peak)
11	Gray Hairstreak	Strymon melinus	Gossamer-winged Butterflies	109	Sep (peak)
12	Red-banded Hairstreak	Calycopis cecrops	Gossamer-winged Butterflies	80	Aug (past peak)
13	Spicebush Swallowtail	Papilio troilus	Swallowtails and Parnassians	68	Aug (past peak)
14	American Lady	Vanessa virginiensis	Brush-footed Butterflies	67	Jun (past peak)
15	Orange Sulphur	Colias eurytheme	Whites, Yellows, and Sulphurs	65	Sep (peak)
16	Red Admiral	Vanessa atalanta	Brush-footed Butterflies	62	Jul (past peak)
17	Least Skipper	Ancyloxypha numitor	Skippers	57	Jul (past peak)
18	Cloudless Sulphur	Phoebis sennae	Whites, Yellows, and Sulphurs	55	Aug (past peak)
19	Fiery Skipper	Hylephila phyleus	Skippers	55	Oct (rising)
20	Red-spotted Admiral	Limenitis arthemis	Brush-footed Butterflies	52	Aug (past peak)
21	Painted Lady	Vanessa cardui	Brush-footed Butterflies	46	Sep (peak)
22	Eastern Comma	Polygonia comma	Brush-footed Butterflies	37	Apr (past peak)
23	Viceroy	Limenitis archippus	Brush-footed Butterflies	29	Sep (peak)
24	Common Checkered-Skipper	Burnsius communis	Skippers	26	Oct (rising)
25	Pipevine Swallowtail	Battus philenor	Swallowtails and Parnassians	25	Aug (past peak)
26	Broad-winged Skipper	Poanes viator	Skippers	25	Jul (past peak)
27	Sleepy Orange	Eurema nicippe	Whites, Yellows, and Sulphurs	23	Aug (past peak)
28	Zabulon Skipper	Lon zabulon	Skippers	22	Aug (past peak)
29	Black Swallowtail	Papilio polyxenes	Swallowtails and Parnassians	18	Sep (peak)
30	American Copper	Lycaena hypophlaeas	Gossamer-winged Butterflies	18	Sep (peak)
31	Summer Azure	Celastrina neglecta	Gossamer-winged Butterflies	16	Jul (past peak)
32	Great Spangled Fritillary	Argynnis cybele	Brush-footed Butterflies	16	Jun (past peak)
33	Question Mark	Polygonia interrogationis	Brush-footed Butterflies	14	Aug (past peak)
34	Horace's Duskywing	Erynnis horatius	Skippers	11	Jul (past peak)
35	Mourning Cloak	Nymphalis antiopa	Brush-footed Butterflies	10	Mar (past peak)
36	American Snout	Libytheana carinenta	Brush-footed Butterflies	10	Jul (past peak)
37	White M Hairstreak	Parrhasius m-album	Gossamer-winged Butterflies	10	Sep (peak)
38	Common Wood-Nymph	Cercyonis pegala	Brush-footed Butterflies	9	Jul (past peak)
39	Clouded Sulphur	Colias philodice	Whites, Yellows, and Sulphurs	8	Jul (past peak)
40	Tawny Emperor	Asterocampa clyton	Brush-footed Butterflies	8	Sep (peak)
41	Salt Marsh Skipper	Panoquina panoquin	Skippers	8	Aug (past peak)
42	Bronze Copper	Tharsalea hyllus	Gossamer-winged Butterflies	8	Jul (past peak)
43	Wild Indigo Duskywing	Erynnis baptisiae	Skippers	6	Aug (past peak)
44	Great Purple Hairstreak	Atlides halesus	Gossamer-winged Butterflies	6	Sep (peak)
45	Appalachian Brown	Lethe appalachia	Brush-footed Butterflies	5	Jun (past peak)
46	Long-tailed Skipper	Urbanus proteus	Skippers	4	Sep (peak)
47	Ocola Skipper	Panoquina ocola	Skippers	4	Oct (rising)
48	Tawny-edged Skipper	Polites themistocles	Skippers	3	Aug (past peak)
49	Meadow Fritillary	Boloria bellona	Brush-footed Butterflies	3	Jun (past peak)
50	Eastern Giant Swallowtail	Heraclides cresphontes	Swallowtails and Parnassians	3	Aug (past peak)