Butterflies of Fermilab (northeastern Illinois)
A list of the butterflies observed on the 6800 acre Fermilab site, 40 miles west of Chicago, Illinois
Includes photographs of most of the species

Species list1 (56 species) 

(footnotes and links to more info may be found below this table)

Click on the species name for photos2

average
peak
count3

typical
peak
month
or date3

comments, locations
(map)

Ecological
significance
rank (1-10)
Remnant 
dependent (R)
or remnant 
associated (r)
(explanation)

Breeding and 
over-wintering
on site (BW), 
breeding but not 
over-wintering (B), 
stray only (S)

Average 
number of 
northern Illinois 
monitoring 
network sites 
reporting this 
species for 
1997, 1998, and 1999

Swallowtails 
(family Papilionidae)

 

 

 

 

 

 

Pipevine Swallowtail (Battus philenor)

(1)

June 1999

an unusual stray!

6, r

S

3

Black Swallowtail (Papilio polyxenes)

5

Aug

 

5

BW

26

Giant Swallowtail (Papilio cresphontes)

2

Aug

ELM-24 woods

8

BW

3

Eastern Tiger Swallowtail (Papilio glaucus)

2

Aug

 

6

BW

26

 

 

 

 

 

 

 

Whites and Sulphurs
(family Pieridae) 

 

 

 

 

 

 

Checkered White (Pontia protodice)

1

Sep 5

southern species

5, r

S

0

Cabbage White (Pieris rapae)

30+

June-Aug

 

1

BW

32

Clouded Sulphur (Colias philodice)

20+

July-Oct

 

5

BW

31

Orange Sulphur (Colias eurytheme)

Data

combined

 with Clouded 

 Sulphur

BW

 

Cloudless Sulphur (Phoebis sennae)

1

June 

southern species

 

S

 

Little Yellow (Eurema lisa)

1

June-Aug

southern species

4

?

4

Dainty Sulphur (Nathalis iole)

1

Aug-Sep

southern species

4

S

0

 

 

 

 

 

 

 

Gossamer-wing Butterflies
(family Lycaenidae) 

 

 

 

 

 

 

Bronze Copper (Lycaena hyllus)

3

Aug 

pond edges 

5, R

BW

8

Purplish Copper (Lycaena helloides)

5

Sep 7

wet fields

5, R

BW

2

Coral Hairstreak (Satyrium titus)

5

July 1

ELM-20

9, r

BW

7

Acadian Hairstreak (Satyrium acadica)

1

July 1

Main Ring

9, r

BW

4

Banded Hairstreak (Satyrium calanus)

3

July 1

ELM-24 woods edge

7, r

BW

8

Oak Hairstreak (Satyrium favonius)

1

July 11

ELM-24 woods edge

 

 

0

Eastern Tailed-Blue (Everes comyntas)

15

Aug 17

 

5

BW

24

Spring Azure (Celastrina ladon)

3

Aug 10

 

7

BW

27

 

 

 

 

 

 

 

Brushfooted Butterflies
(family Nymphalidae)

 

 

 

 

 

 

American Snout (Libytheana carinenta)

1

July-Sep

 

4

B

7

Variegated Fritillary (Euptoieta claudia)

(2)

Aug 2001

ELM-20

4

S

1

Great Spangled Fritillary (Speyeria cybele)

7

June 27

Interpretive trail/woods

5, r

BW

25

Meadow Fritillary (Boloria bellona)

10

June 24
July 31
Sep 6

old fields with violets

9, R

BW

1

Silvery Checkerspot (Chlosyne nycteis)

1

June

 

 

? a new sighting

 

Pearl Crescent (Phyciodes tharos)

13

July-Aug

 

5

BW

29

Question Mark (Polygonia interrogationis)

4

May-Sep

 

6

BW

11

Eastern Comma (Polygonia comma)

3

April, 
July-Oct

ELM-24 woods

6

BW

11

Gray Comma (Polygonia progne)

2

July-Aug

ELM-24 woods

6, r

BW

3

Mourning Cloak (Nymphalis antiopa)

2

Apr-Sep

 

6

BW

18

American Lady (Vanessa virginiensis)

3

May-June

 

5

B

16

Painted Lady (Vanessa cardui)

4

Aug-Sep

 

4

B

6

Red Admiral (Vanessa atalanta)

7

May-Sep

 

6

B

19

Common Buckeye (Junonia coenia)

5

July-Sep

 

4

B

13

Red-spotted Purple (Limenitis arthemis)

3

Aug 1

 

6

BW

16

Viceroy (Limenitis archippus)

10

June-Aug

Willows at pond edges

6, r

BW

18

Satyrs (subfamily Satyrinae) 

 

 

 

 

 

 

Northern Pearly-eye (Enodia anthedon)

5

July

ELM-24 woods

7, r

BW

11

Eyed Brown (Satyrodes eurydice)

2

July 6

ELM-1, ELM-20

10, R

BW

11

Little Wood-Satyr (Megisto cymela)

1

June 

ELM-24 woods

7

BW

17

Common Wood-Nymph (Cercyonis pegala)

15

July 

prairies and fields

9, r

BW

20

Milkweed butterflies 
(subfamily Danainae)

 

 

 

 

 

 

Monarch (Danaus plexippus)

10+

Sep

 

4

B

31

 

 

 

 

 

 

Skippers (family Hesperiidae)

 

 

 

 

 

 

Silver-spotted Skipper (Epargyreus clarus)

4

June-Aug

ELM-24 woods

 

BW

23

Wild Indigo Duskywing (Erynnis baptisiae)

5

Sep 

widespread on site

 

BW

5

Common Checkered-Skipper (Pyrgus communis)

(1)

July 2000

 

 

S

1

Common Sootywing (Pholisora catullus)

(1)

Aug 2001

 

 

?

4

Least Skipper (Ancyloxypha numitor)

12

June, Aug

 

r

BW

13

European Skipper (Thymelicus lineola)

12

June 25

 

 

BW

16

Fiery Skipper (Hylephila phyleus)

4

Aug-Sep

 

 

B

7

Peck's Skipper (Polites peckius)

4

June 10

interpretive trail

 

BW

15

Tawny-edged Skipper (Polites themistocles)

2

June 4

 

 

BW

12

Northern Broken-Dash (Wallengrenia egeremet)

4

July 14

ELM-24 woods edge

 

BW

4

Little Glassywing (Pompeius verna)

(1)

June 2001

ELM-1

 

?

2

Sachem (Atalopedes campestris)

(1)

Sep 2000

 

 

S

1

Delaware Skipper (Anatrytone delaware)

2

July 

ELM-1,ELM-20

r

BW

11

Dion Skipper (Euphyes dion)

16

July 10

Indian Creek (ELM-27)

R

BW

5

Black Dash (Euphyes conspicua)

2

July 8

sedges near ELM-3

R

BW

6

Dun Skipper (Euphyes vestris)

3

July 13

 

 

BW

7


Footnotes and more information:

1.  Observations by Tom Peterson.  The common and scientific names given here follow the North American Butterfly Association's list of "English Names of North American Butterflies Occuring North of Mexico".   

    Have a look at a few other Kane County and DuPage County butterflies not yet found at Fermilab.
2.  Unless otherwise noted, all photographs linked to this page were taken by Tom Peterson.  See photo notes for more information about the photography.
3.  The number of individuals of a species seen is recorded as approximately the number of sightings per hour.  Peak count is not based on a methodical, periodic count, so it is just a rough indicator of relative abundance.  The average peak count is for the years 1999-2003.  Where the peak count has been on nearly the same date each year, a specific average date is given.  When the date of peak count has varied, a range of time is given.  Sightings in parentheses indicate that the species has only been seen on site once in the past four years; the year and month are given.  Have a look at the Table of Observational Data for yearly peak counts and dates.
 


 

Some links to other Fermilab web sites:

Some links to other lepidoptera web sites:

For more information contact Tom Peterson (tommy@fnal.gov), 630 840 4458.
Last update:  August 16, 2012
 
 


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