12 
This is “a very old record,” according to Wyatt (per- 
sonal communication). It is probably casual, as Illinois 
lies somewhat south of the normal range of this sub- 
species of centaurae. 
Pyrgus communis (Grote) 
Checkered skipper 
tHesperia tessellata Scudder (nec Hewitson) 1872:73 
(type-locality “Pennsylvania, Maryland, Iowa, Flori- 
da, Alabama, Texas, Missouri and California’’). 
Syricthus communis Grote 1872:69 (type-locality “Cen- 
tral Alabama’’). 
Pyrgus tessellata: Worthington 1880: 49. 
Hesperia communis: Holland LOS o42. 
Pyrgus communis: Klots 1951:215; dos Passos 1964:19 
(No. 161). 
Illinois records.—Map 20. 
The checkered skipper, common throughout Illinois, 
is a characteristic species of autumn; early season records 
are few. There is considerable color variation. Records 
are available from March 22 through November, 14, but 
the species reaches its greatest abundance during late 
August and throughout September. 
Erynnis icelus (Scudder & Burgess ) 
Dreamy dusky wing 
Nisoniades icelus Scudder & Burgess 1870:288 (type- 
locality “New England”). 
Thanaos icelus: Worthington 1880:49; Holland 1931: 
350. 
Erynnis icelus: Klots 1951:222; dos Passos 1964: 20 (No. 
163). 
Illinois records—Coox County: Palos Park, May 
99 192 7,e May 30;-193 1 ierz (FMNH); Palos Park, 
May 31, 1914, Gerhard (FMNH); Palos Park, May ds 
1922, May 30, 1923, Beer (INHS). LAKE COUNTY: 
“Beach” (Waukegan Dunes), May 21, 1922, Wyatt 
(FMNH). McHenry County: Algonquin, June 8, 
June 11, Nason (INHS). Mapison County: Alton, 
April, 1948, Lauck (P. S. Remington 1948). 
E. icelus is superficially similar to Erynnis brizo, but 
the genitalia offer abundant distinct characters. Like 
brizo, it is a single-brooded spring species, but appears 
somewhat later in the season. It appears to be less 
common than brizo; we have numerous records of the 
latter, but the above are the only Illinois records of the 
present species. We have not seen the material on which 
the Alton record is based and suggest that there may 
be a slight question as to its correctness since the locality 
is widely disjunct from the remainder of the known 
range of icelus in Illinois. It may, however, occur in 
the intervening territory, having been overlooked or con- 
fused with the following species. 
Erynnis brizo (Boisduval & Le Conte) 
Sleepy dusky wing 
Thanaos brizo Boisdual & Le Conte 1834: Plate 66 
(type-locality “North America”). 
Thanaos brizo: Worthington 1880:49; Holland 1931: 
349. 
Erynnis brizo: Klots 1951:222; dos Passos 1964:20 (No. 
164). 
Illinois records—Map 21. 
E. brizo is rather common, probably throughout Illi. 
nois, although available records are widely scattered. I 
is a single-brooded, early spring butterfly of woodlanc 
roads and clearings. It has been recorded as early a 
March 30 and as late as May 18. 
Erynnis baptisiae (Forbes) 
Wild indigo dusky wing 
Thanaos baptisiae Forbes 1936:111 
“Woods Hole, Massachusetts’’) . 
Erynnis baptisiae: Klots 1951 -227; dos Passos 1964:2 
(No. 167). 
Illinois records—Map 22. 
This species and E. lucilius constitute a pair of nea 
ly indistinguishable but biologically divergent sibling 
differing almost entirely in food-plant selection. Unlik 
the other species of Erynnis in Illinois, these are ir 
separable by means of genitalic characters. For th 
reason, it is virtually impossible to separate them wit 
certainty when host plant association is lacking. TI 
species are monophagous, E. baptisiae feeding upon Ba; 
tisia (wild indigo), and FE. lucilius on Aquilegia (colun 
bine). Burns (1964) stated that there are indicatio1 
of differences in larval morphology. Differentiation | 
the adults is complicated by the presence in both speci 
of two differing temporal phenotypes. 
The older literature is almost wholly unreliable b 
cause of authors’ failure to separate properly the speci 
comprising this complex. Before the recognition of ba 
tisiae as a separate species, it was lumped with pers 
or lucilius; most old records of “E. persius” from t 
eastern states, probably including that of Worthingt: 
from Illinois, actually refer to baptisiae. 
E. baptisiae is the dominant member of the coi 
plex in Illinois. The existence of E. lucilius and pers 
in Illinois has not been confirmed. Only records bas 
on specimens with positive food plant association dé 
have been accepted. H. A. Freeman determined a nu 
ber of Illinois Erynnis,as E. baptisiae (Fig. 1), and th 
records have likewise been accepted. E. baptisiae is prc 
ably statewide in distribution and common, althou 
authentic records are few and widely scattered. J 
record from Macon County is that of the allotype 
male from Decatur. 
Host-associated material is greatly needed in or 
to determine accurately the range of baptisiae in I 
nois, as well as to confirm the suspected presence 
lucilius. E. baptisiae is multivoltine, with dates of ci 
ture in Illinois ranging from April 17 through Septe 
ber 10, and develops differing spring and summer phe: 
types as above indicated. 
Burns (1964) presented a monographic treatment 
the genus Erynnis. The persius species group recel’ 
special attention. 
(type-localit 
Erynnis zarucco (Lucas) 
Zarucco dusky wing 
1857:641 (type-local 
Thanaos zarucco Lucas 
“Cuba, .) 
Thanaos terentius: Holland 1931:354. 
Erynnis zarucco: Klots 1951:227; dos Passos 1964 
(No. 168). 
