(excerpt)
On 26 June, 1976, I stopped to examine plants and collect insects on the alvars or limestone barrens on Great La Cloche Island, north of Little Current in Manitoulin District, Ontario. 1 was especially interested to learn whether or not there were any insects of western affinity in this area since some of the plant species present are at, or near to, the eastern limits of their distribution (Catling et al., 1975). It was mild and sunny, and insects were abundant. Within a few minutes 1 noticed a dark, fast-flying skipper that otherwise resembled Thymeliczrs lineola (Ochsenheimer). The dark colour and whitish veins on the hind wing beneath suggested Oarisma powesheik (Parker), a midwestern species known in Michigan since 1893 (McAlpine, 1972) and recently discovered further to the east and south within the state (Holzman, 1972; Wagner, 1976, pers. comm.). However, the relatively small size made this identification unlikely. 1 captured a few specimens, but had to leave the area without investigating the habitat, abundance and local distribution of the unfamiliar butterfly. The earliest opportunity for further investigation came a week later on 3 July, when I was again favoured with a warm sunny day. After collecting in a variety of habitats, I finally arrived on the alvar on the west side of highway 68 in the immediate vicinity of McGregor Bay, La Cloche Peninsula (ca. 46 02\u27 North, 81°46\u27 West). I collected several specimens of the strange little skipper and saw at least 20 within one half hour, then continued south on highway 68 onto Great La Cloche Island. Here south of the highway and the Canadian Pacific railway tracks, and south and west of Lewis Lake (ca. 46 OO\u27 North, 81°52\u27 West), I found at least 10 more of the skippers in similar alvar habitat. Both of these locations are south of Espanola and north of Little Current in the North Channel, Manitoulin District, Ontario

Catling, Paul M

English

ValpoScholar

The Great Lakes Entomologist 
Volume 10 
Number 2 - Summer 1977 Number 2 - Summer 
1977 
Article 4 
June 1977 
On the Occurrence of Oarisma Garita (Reakirt) (Lepidoptera: 
Hesperiidae) in Manitoulin District, Ontario 
Paul M. Catling 
University of Toronto 
Follow this and additional works at: https://scholar.valpo.edu/tgle 
 Part of the Entomology Commons 
Recommended Citation 
Catling, Paul M. 1977. "On the Occurrence of Oarisma Garita (Reakirt) (Lepidoptera: Hesperiidae) in 
Manitoulin District, Ontario," The Great Lakes Entomologist, vol 10 (2) 
Available at: https://scholar.valpo.edu/tgle/vol10/iss2/4 
This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. 
It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. 
For more information, please contact a ValpoScholar staff member at scholar@valpo.edu. 
THE GREAT LAKES ENTOMOLOGIST 
ON THE OCCLIRRENCE OF OARISMA GARITA (REAKIRT) 
(LEPIDOPTERA: HESPERIIDAE) I N MANlTOULlN DISTRICT, ONTARIO 
Paul M. catling1 
On 26 June, 1976, I stopped to examine plants and collect insects on the alvars or 
limestone barrens on Great La Cloche Island, north of Little Current in Manitoulin 
District, Ontario. 1 was especially interested to learn whether or not there were any 
insects of western affinity in this area since some of the plant species present are at, or 
near to, the eastern limits of their distribution (Catling et al., 1975). It was mild and 
sunny, and insects were abundant. Within a few minutes 1 noticed a dark, fast-flying 
skipper that otherwise resembled Thymeliczrs lineola (Ochsenheimer). The dark colour 
and whitish veins on the hind wing beneath suggested Oarisma powesheik (Parker), a 
midwestern species known in Michigan since 1893 (McAlpine, 1972) and recently 
discovered further to the east and south within the state (Holzman, 1972; Wagner, 1976, 
pers. comm.). However, the relatively small size made this identification unlikely. 1 
captured a few specimens, but had to leave the area without investigating the habitat, 
abundance and local distribution of the unfamiliar butterfly. The earliest opportunity for 
further investigation came a week later on 3 July, when I was again favoured with a 
warm sunny day. After collecting in a variety of habitats, I finally arrived on the alvar on 
the west side of highway 68 in the immediate vicinity of McGregor Bay, La Cloche 
Peninsula (ca. 46"02' North, 81°46' West). I collected several specimens of the strange 
little skipper and saw at least 20 within one half hour, then continued south on highway 
68 onto Great La Cloche Island. Here south of the highway and the Canadian Pacific 
railway tracks, and south and west of Lewis Lake (ca. 46"OO' North, 81°52' West), I 
found at least 10 more of the skippers in similar alvar habitat. Both of these locations are 
south of Espanola and north of Little Current in the North Channel, Manitoulin District, 
Ontario. 
Upon returning home and consulting the literature, I was somewhat surprised to find 
that the skippers were clearly Oarisma garita (Reakirt), a common species of the northern 
and western Great Plains and Rocky Mountains, ranging from Washington and British 
Columbia east to Manitoba and Saskatchewan and south through Idaho, Montana, and 
the Dakotas to Mexico (MacNeill, 1975). The species has not been recorded previously 
from Ontario (Riotte, 1970, 1971, 1972). Dr. C. Don MacNeill of the Oakland Museum, 
California, has kindly confirmed this identification as garita (pers. comm.), which 
establishes a colony at least 650 miles east of any previously known, a remarkable 
extension of known range. 
HABITAT 
Since this occurrence apparently represents a significant disjunction, and is the first 
record for Ontario, it may be well to describe the area in some detail. The skippers were 
found exclusively in more or less flat calcareous barrens where the limestone bedrock was 
at or near the surface (Fig. I). The plant associations appear as a mosaic dependent upon 
many factors, especially moisture regime. Vegetation varies greatly over short distances. 
The higher and drier areas of exposed rock are characterized by Andropogotz scoparius, 
Prunus depressa, Arcfostaphylos uva-ursi, Juniperus horizontalis, Poterztilla fruticosa, 
Liatris cylindracea, Carex scirpoidea, Carex richardsonii and Asclepias viridiflora var. 
linearis. Somewhat lower areas are dominated by Sporobolus heterolepis and Descliampsia 
cespitosa with Panicum lindheimeri and Sczlfellaria parvula. In places where the ground is 
periodically inundated or where there is occasional seepage, Eleocharis compressa, Carex 
viridula, Carex crabc~ei, Allium schoenoprasm var. sibiricum, Agrostis hyemalis var. tenz~is, 
l ~ e ~ a r t m e n t of Botany, University of Toronto, Toronto, M5S l A l , Ontario, Canada. 
1
Catling: On the Occurrence of Oarisma Garita (Reakirt) (Lepidoptera
Published by ValpoScholar, 1977
THE GREAT LAKES ENTOMOLOGIST Vol. 10. No. 2 
Fig. 1. Alvar habitat of Oarisma garita with Sporobolus heterolepis and Eleocharis 
compressa surrounded by Pinus banksiana. Photographed 3 July, 1976, McGregor Bay, 
La Cloche Peninsula. 
Satureja arkansana and Isanthus brachiatus are characteristic. Permanently wet marshes 
are scattered over the area. These have Cladium mariscoides, Carex lasiocarpa, Carex 
flava, Carex buxbaumii and Juncus balticus. Where these permanent wetlands grade into 
drier ground as they do over large areas, a great many species are present in various 
combinations. Danthonia spicata, Prunella vulgaris, Cornandra richardsiana, Agropyron 
repens, Senecio pauperculus, Bromus kalmii and Carex granularis are frequent here. Other 
species include Geum hiflorum, Castilleja coccinea, Poa compressa, Solidago ohioensis, 
Aster laevis and Aster ptarmicoides. Scattered here and there, and surrounding the barren 
area are more or less open stands of Pinus banksiana and clumps of various shrubs such 
as Rhus aromutica, Amelanchier alnifolia var. compacta and Amelanchier sanguinea. 
All of the skippers were seen in open areas, mostly along the marsh edges, visiting the 
flowers of Prunella vulgaris and Asclepias incarnata, and also in the areas dominated by 
Eleocharis compressa and Sporobolus heterolepis where they were frequently seen on 
flowers of Satureja arkansana. They generally flew within a few metres of the ground, 
their fast flight and dark colour making them difficult to follow. 
Other lepidoptera common on the Cloche alvars on 3 July were Thymelicus lineola 
(Ochsenheimer), Polites thermistocles (Latreille), Polites mystic (Edwards), Polites origines 
(Fabricius), Phyciodes tharos (Drury), Phyciodes batesii Reakirt, Coenonympha irzornata 
inornata Edwards and worn Chlosyne harrisii harrisii (Scudder). 
BIOGEOGRAPHlCAL NOTES 
Many of the older literature reports of 0. garita in the eastern part of its range 
actually refer to 0. powesheik. The latter is a larger and darker species, with the veins on 
the hind wing more distinctly whitened. A specimen from lllinois (ROM) has the 
2
The Great Lakes Entomologist, Vol. 10, No. 2 [1977], Art. 4
https://scholar.valpo.edu/tgle/vol10/iss2/4
1977 THE GREAT LAKES ENTOMOLOGIST 61 
forewing 13.5 mm. long and the antennae 5.5 mm., while all garita from the Cloche area 
are much smaller with the forewing 11.5 mm. and the antennae 4.8 mm. Other 
differences are described by MacNeill (1975), who refers to garita as "con~mon" in the 
northern and western Great Plains and Rocky Mountains. Johnson (1972) states that 
powesheik is the common species of the midwestern U.S., and that garita is essentially a 
more western species characteristic of the Rocky Mountains. Similarly, Irwin and Downey 
(1973) consider it probable that old references to garita in Illinois actually refer to 
powesheik, and that "it is unlikely that true 0. garita occurs as far east as Illinois." It 
appears then that garita is at least rare and local, if not highly disjunctive, in the eastern 
part of its range. However, in view of recent movements of fauna from the west to the 
east (several birds are notable) and the small size of this insect, as well as the very 
incomplete knowledge of the status and distribution of insects, other than economically 
important species, in Ontario, it might be assumed that garita is spreading eastward. 
Among lepidoptera, Euchloe ausonides Lucas is believed to have recently extended its 
range eastward in Ontario (Tasker, 1970), and the western nearctic Plebejus saepiolus 
Boisduval appears to have recently pushed eastward into northern Ontario where it occurs 
in pasture lands and along highway verges, the larvae feeding on introduced clovers 
(7'rifolium spp.). There are, however, insects having an extensive distribution in the 
western cordillera of the U.S. that extend eastward transcontinentally in Canada, and for 
which evidence for a recent eastward expansion resulting from human activity is far less 
convincing. An example is Coenonvmpha inornata. There are also a number of vascular 
plant species that are distributed over a large area of the western cordillera, with a 
disjunction into the upper Great Lakes region, which certainly appear to be relict rather 
than recent. Present biogeographical evidence then does not necessarily imply a recent 
eastward spread of garita. 
If garita were extending its range to the east, i t would likely be found in open 
habitats resulting from human activity, such as highway verges and pasture lands, further 
to the west. However, on the same day as this skipper was abundant in the Cloche area, it 
could not be found despite extensive search of roadsides, marshlands and wet and dry 
meadows near Espanola, Webbwood, and Massey in Sudbury District to the north and 
west. Nor could it be located with appropriate weather on 4 July, in natural meadow 
habitats at Oliphant and Cape Croker in Bruce County. The "usual" butterflies, such as 
Polites thermistocles, Thymelicus lineola, Polites mystic, Phyciodes tharos, were abundant 
in all of these places. It appears then that garita is not extending eastward, but rather the 
populations in the Cloche area may represent relicts from a once more continuous 
distribution connecting with western populations. The apparent restriction of garita in the 
Cloche area to the natural alvars, areas with unusual native vegetation, further suggests 
relict status. Although much more study will be necessary to determine beyond any 
doubt the extent of the disjunction, it need not prevent some speculation concerning the 
manner in which such a disjunctive occurrence might arise, and whether or not it is 
indeed relict. 
Shapiro (1970) has suggested an eastward movement of Plebejus melissa samuelis 
Nabokov during the warmer and drier xerothermic period ca. 5,000 B.P. The alvar 
vegetation may have been more widespread during the xerothermic period, and some of 
the alvar plants in Manitoulin District are distinctly western (Catling et al., 1975). The 
occurrence of prairie chickens [7'ympanuchus czipido (Linnaeus)] on Manitoulin Island is 
another western feature of the area. Could garita be a xerothermic relict? This might 
explain eastern occurrences of the midwestern powesheik, but it does not seem an 
adequate explanation for the advent of an insect of an apparently cooler, more western 
and cordilleran environment. 
The disjunction of vascular plant species of the western cordillera in the upper Great 
Lakes region has already been alluded to. Frequently this disjunction pattern involves the 
Gaspe peninsula as well. Presumably these plants are relicts of a once continuous arctic 
and subarctic or at least cool temperate environment that existed in these latitudes across 
much of North America for a brief internal, perhaps several hundred years, as the 
3
Catling: On the Occurrence of Oarisma Garita (Reakirt) (Lepidoptera
Published by ValpoScholar, 1977
6 2 THE GREAT LAKES ENTOMOLOGIST Vol. 10, No. 2 
continental glaciers melted back northward ca. 9,000-10,OOOB.P. (Zoltai, 1968; 
Terasmae, 1968). The shorelines of the postglacial upper Great Lakes were continuous 
with Lake Agassiz to the west ca. 10,000 B.P. (Zoltai, 1968), and the gradually dropping 
water levels of these lakes exposing new land for colonization may have provided a 
corridor for the immigration of western fauna and flora that may have otherwise 
maintained its western distribution during the Wisconsin advance. The plants could have 
persisted as disjuncts in local areas where a cool environment was maintained. Although 
the Cloche area was inundated by glacial Lake Algonquin-Nipissing perhaps until 
4,000 B.P. (Zoltai, 1968), other parts of Manitoulin District were gradually emerging and 
it is conceivable that garita existed in the immediate vicinity. isostatic rebound resulting 
in the continuing emergence of new limestone barren habitats, and later the maintainence 
of these as open habitats by periodic fire, drought, and fluctuating lake levels, and finally 
the perpetuation of a cool environment by the moderating effect of a large body of 
water, might have maintained a suitable habitat for garita since early postglacial times. 
If an appropriate environment were maintained in the area for 10,000 years, one 
wonders about the possibility of a gravid female wandering in or being blown in from the 
far west a number of times since then. Wagner (1972) has suggested long-distance spore 
dispersal by the prevailing winds from the west as one possible explanation for west to 
east disjunctions of homosporous vascular plants. Pieris protodice Boisduval and LeConte 
provides a good example of a butterfly species of the south and west that moves into 
local areas of southern Ontario, and establishes colonies for a few to several years, only 
to disappear when the ephemeral habitats with annual mustard species decline. However, 
this kind of wind blown or wandering disjunction seems unlikely with a local species of 
more or less stable habitats as garita appears to be. 
One must exercise caution in assuming natural disjunction. The likelihood of transport 
by man is difficult to evaluate. Who has n o t carried a bothersome bee or fly several miles 
in a car, and what entomologist has no t been impressed by the diversity of insects on the 
fronts of cars a t service centres along the highway? It does seem possible, although 
unlikely, that a gravid female could travel by vehicle from the far west and establish a 
colony in the east. A purposeful introduction seems even less likely. 
Is garita in the Cloche area disjunct 650 miles or more, and does this actually represent 
a postglacial relict? Are other insects disjunctive in this area? Definite answers will require 
more study of the Cloche area, and more information on the ecology and distribution of 
Oarisnla spp. elsewhere. 
The Cloche area is biologically unique and the Garita Skipper only adds to its unique 
quality, and a t the same time poses some most interesting questions. Hopefully some 
examples of the alvars in the Cloche area will be preserved for biological research, 
maintainance of unique genetic material, and for their unusual diversity of flora and 
fauna. 
DISPOSITION OF SPECIMENS AND ACKNOWLEDGMENTS 
Of eight specimens of garita collected in the Cloche area, two were sent to Dr. C. Don 
MacNeill of the Oakland Museum, California, two were deposited in the collection of the 
Department of Entomology at the Royal Ontario Museum, Toronto, and three are in the 
private collections of P. M. Catling, M. C. Nielsen, and W. H. Wagner. My thanks to Prof. 
Wagner for his critical reading, to Dr. MacNeill for confirming the identification of 
specimens, to Mr. Nielsen for his correspondence, and to Miss K. L. McIntosh for 
assistance in the field. 
LITERATURE ClTED 
Catling, P. M., J. E. Cruise, K. L. McIntosh and S. M. McKay 1975. Alvar vegetation in 
southern Ontario. Ont. Field Biol. 29:l-25. 
4
The Great Lakes Entomologist, Vol. 10, No. 2 [1977], Art. 4
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1977 THE GREAT LAKES ENTOMOLOGIST 63 
Holzman, R. W. 1972. Eastern range extension for Oarisma powesheik Parker (Lepidop- 
tera: Hesperiidae). Great Lakes Entomol. 5: 1 11-1 14. 
Irwin, R. R. and J. C. Downey 1973. Annotated checklist of the butterflies of Illinois. 
Ill. Nat. Hist. Surv. Biol. Notes 81. 60 p. 
Johnson, K. 1972. The butterflies of Nebraska. J. Res. Lepid. 11: 1-64. 
MacNeill, C. D. 1975. Hesperiidae, p. 423-578 in Howe, W. H., The butterflies of North 
America. Doubleday, N.Y. 633 p. 
McAlpine, W. S. 1972. Observations of the life history of Oarisma powesheik (Parker) 
1870. J. Res. Lepid. ll:83-93. 
Munroe, E. 1968. Insects of Ontario: Geographical distribution and post-glacial origin. 
Proc. Entomol. Soc. Ont. 99:43-50. 
Riotte, J. C. E. 1970. Checklist of Ontario skippers and butterflies. Toronto Entomol. 
Assn., Occ. PubI. 1: 1-4. 
- 1971. Butterflies and skippers of northern Ontario. MidCont. Lepid. Series 
2:l-20. 
1972. On the distribution of some skippers in Ontario. J. Res. Lepid. 
11:81-82. 
Shapiro, A. M. 1970. Postglacial biogeography and the distribution of Poanes viator 
(Hesperiidae) and other marsh butterflies. J. Res. Lepid. 9:125-155. 
Tasker, R. R. 1970. Further eastward extension of the range of Euchloe ausonides mqyi 
(Pieridae) in Ontario. J. Lepid. Soc. 24:226. 
Terasmae, J. 1968. A discussion of deglaciation and the boreal forest history in the 
northern Great Lakes region. Proc. Entomol. Soc. Ont. 99:31-43. 
Wagner, W. H. 1972. Disjunctions in homosporous vascular plants. Ann. Mo. Bot. Garden, 
59:203-217. 
Zoltai, S. C. 1968. Glacial history of the upper Great Lakes. Proc. Entomol. Soc. Ont. 
99: 15-20. 
5
Catling: On the Occurrence of Oarisma Garita (Reakirt) (Lepidoptera
Published by ValpoScholar, 1977

On the Occurrence of \u3ci\u3eOarisma Garita\u3c/i\u3e (Reakirt) (Lepidoptera: Hesperiidae) in Manitoulin District, Ontario

Valparaiso University

The Great Lakes Entomologist Volume 10 Number 2 - Summer 1977 Number 2 - Summer 1977 Article 4 June 1977 On the Occurrence of Oarisma Garita (Reakirt) (Lepidoptera: Hesperiidae) in Manitoulin District, Ontario Paul M. Catling University of Toronto Follow this and additional works at: https://scholar.valpo.edu/tgle Part of the Entomology Commons Recommended Citation Catling, Paul M. 1977. "On the Occurrence of Oarisma Garita (Reakirt) (Lepidoptera: Hesperiidae) in Manitoulin District, Ontario," The Great Lakes Entomologist, vol 10 (2) Available at: https://scholar.valpo.edu/tgle/vol10/iss2/4 This Peer-Review Article is brought to you for free and open access by the Department of Biology at ValpoScholar. It has been accepted for inclusion in The Great Lakes Entomologist by an authorized administrator of ValpoScholar. For more information, please contact a ValpoScholar staff member at scholar@valpo.edu. THE GREAT LAKES ENTOMOLOGIST ON THE OCCLIRRENCE OF OARISMA GARITA (REAKIRT) (LEPIDOPTERA: HESPERIIDAE) I N MANlTOULlN DISTRICT, ONTARIO Paul M. catling1 On 26 June, 1976, I stopped to examine plants and collect insects on the alvars or limestone barrens on Great La Cloche Island, north of Little Current in Manitoulin District, Ontario. 1 was especially interested to learn whether or not there were any insects of western affinity in this area since some of the plant species present are at, or near to, the eastern limits of their distribution (Catling et al., 1975). It was mild and sunny, and insects were abundant. Within a few minutes 1 noticed a dark, fast-flying skipper that otherwise resembled Thymeliczrs lineola (Ochsenheimer). The dark colour and whitish veins on the hind wing beneath suggested Oarisma powesheik (Parker), a midwestern species known in Michigan since 1893 (McAlpine, 1972) and recently discovered further to the east and south within the state (Holzman, 1972; Wagner, 1976, pers. comm.). However, the relatively small size made this identification unlikely. 1 captured a few specimens, but had to leave the area without investigating the habitat, abundance and local distribution of the unfamiliar butterfly. The earliest opportunity for further investigation came a week later on 3 July, when I was again favoured with a warm sunny day. After collecting in a variety of habitats, I finally arrived on the alvar on the west side of highway 68 in the immediate vicinity of McGregor Bay, La Cloche Peninsula (ca. 46"02' North, 81°46' West). I collected several specimens of the strange little skipper and saw at least 20 within one half hour, then continued south on highway 68 onto Great La Cloche Island. Here south of the highway and the Canadian Pacific railway tracks, and south and west of Lewis Lake (ca. 46"OO' North, 81°52' West), I found at least 10 more of the skippers in similar alvar habitat. Both of these locations are south of Espanola and north of Little Current in the North Channel, Manitoulin District, Ontario. Upon returning home and consulting the literature, I was somewhat surprised to find that the skippers were clearly Oarisma garita (Reakirt), a common species of the northern and western Great Plains and Rocky Mountains, ranging from Washington and British Columbia east to Manitoba and Saskatchewan and south through Idaho, Montana, and the Dakotas to Mexico (MacNeill, 1975). The species has not been recorded previously from Ontario (Riotte, 1970, 1971, 1972). Dr. C. Don MacNeill of the Oakland Museum, California, has kindly confirmed this identification as garita (pers. comm.), which establishes a colony at least 650 miles east of any previously known, a remarkable extension of known range. HABITAT Since this occurrence apparently represents a significant disjunction, and is the first record for Ontario, it may be well to describe the area in some detail. The skippers were found exclusively in more or less flat calcareous barrens where the limestone bedrock was at or near the surface (Fig. I). The plant associations appear as a mosaic dependent upon many factors, especially moisture regime. Vegetation varies greatly over short distances. The higher and drier areas of exposed rock are characterized by Andropogotz scoparius, Prunus depressa, Arcfostaphylos uva-ursi, Juniperus horizontalis, Poterztilla fruticosa, Liatris cylindracea, Carex scirpoidea, Carex richardsonii and Asclepias viridiflora var. linearis. Somewhat lower areas are dominated by Sporobolus heterolepis and Descliampsia cespitosa with Panicum lindheimeri and Sczlfellaria parvula. In places where the ground is periodically inundated or where there is occasional seepage, Eleocharis compressa, Carex viridula, Carex crabc~ei, Allium schoenoprasm var. sibiricum, Agrostis hyemalis var. tenz~is, l ~ e ~ a r t m e n t of Botany, University of Toronto, Toronto, M5S l A l , Ontario, Canada. 1Catling: On the Occurrence of Oarisma Garita (Reakirt) (LepidopteraPublished by ValpoScholar, 1977THE GREAT LAKES ENTOMOLOGIST Vol. 10. No. 2 Fig. 1. Alvar habitat of Oarisma garita with Sporobolus heterolepis and Eleocharis compressa surrounded by Pinus banksiana. Photographed 3 July, 1976, McGregor Bay, La Cloche Peninsula. Satureja arkansana and Isanthus brachiatus are characteristic. Permanently wet marshes are scattered over the area. These have Cladium mariscoides, Carex lasiocarpa, Carex flava, Carex buxbaumii and Juncus balticus. Where these permanent wetlands grade into drier ground as they do over large areas, a great many species are present in various combinations. Danthonia spicata, Prunella vulgaris, Cornandra richardsiana, Agropyron repens, Senecio pauperculus, Bromus kalmii and Carex granularis are frequent here. Other species include Geum hiflorum, Castilleja coccinea, Poa compressa, Solidago ohioensis, Aster laevis and Aster ptarmicoides. Scattered here and there, and surrounding the barren area are more or less open stands of Pinus banksiana and clumps of various shrubs such as Rhus aromutica, Amelanchier alnifolia var. compacta and Amelanchier sanguinea. All of the skippers were seen in open areas, mostly along the marsh edges, visiting the flowers of Prunella vulgaris and Asclepias incarnata, and also in the areas dominated by Eleocharis compressa and Sporobolus heterolepis where they were frequently seen on flowers of Satureja arkansana. They generally flew within a few metres of the ground, their fast flight and dark colour making them difficult to follow. Other lepidoptera common on the Cloche alvars on 3 July were Thymelicus lineola (Ochsenheimer), Polites thermistocles (Latreille), Polites mystic (Edwards), Polites origines (Fabricius), Phyciodes tharos (Drury), Phyciodes batesii Reakirt, Coenonympha irzornata inornata Edwards and worn Chlosyne harrisii harrisii (Scudder). BIOGEOGRAPHlCAL NOTES Many of the older literature reports of 0. garita in the eastern part of its range actually refer to 0. powesheik. The latter is a larger and darker species, with the veins on the hind wing more distinctly whitened. A specimen from lllinois (ROM) has the 2The Great Lakes Entomologist, Vol. 10, No. 2 [1977], Art. 4https://scholar.valpo.edu/tgle/vol10/iss2/41977 THE GREAT LAKES ENTOMOLOGIST 61 forewing 13.5 mm. long and the antennae 5.5 mm., while all garita from the Cloche area are much smaller with the forewing 11.5 mm. and the antennae 4.8 mm. Other differences are described by MacNeill (1975), who refers to garita as "con~mon" in the northern and western Great Plains and Rocky Mountains. Johnson (1972) states that powesheik is the common species of the midwestern U.S., and that garita is essentially a more western species characteristic of the Rocky Mountains. Similarly, Irwin and Downey (1973) consider it probable that old references to garita in Illinois actually refer to powesheik, and that "it is unlikely that true 0. garita occurs as far east as Illinois." It appears then that garita is at least rare and local, if not highly disjunctive, in the eastern part of its range. However, in view of recent movements of fauna from the west to the east (several birds are notable) and the small size of this insect, as well as the very incomplete knowledge of the status and distribution of insects, other than economically important species, in Ontario, it might be assumed that garita is spreading eastward. Among lepidoptera, Euchloe ausonides Lucas is believed to have recently extended its range eastward in Ontario (Tasker, 1970), and the western nearctic Plebejus saepiolus Boisduval appears to have recently pushed eastward into northern Ontario where it occurs in pasture lands and along highway verges, the larvae feeding on introduced clovers (7'rifolium spp.). There are, however, insects having an extensive distribution in the western cordillera of the U.S. that extend eastward transcontinentally in Canada, and for which evidence for a recent eastward expansion resulting from human activity is far less convincing. An example is Coenonvmpha inornata. There are also a number of vascular plant species that are distributed over a large area of the western cordillera, with a disjunction into the upper Great Lakes region, which certainly appear to be relict rather than recent. Present biogeographical evidence then does not necessarily imply a recent eastward spread of garita. If garita were extending its range to the east, i t would likely be found in open habitats resulting from human activity, such as highway verges and pasture lands, further to the west. However, on the same day as this skipper was abundant in the Cloche area, it could not be found despite extensive search of roadsides, marshlands and wet and dry meadows near Espanola, Webbwood, and Massey in Sudbury District to the north and west. Nor could it be located with appropriate weather on 4 July, in natural meadow habitats at Oliphant and Cape Croker in Bruce County. The "usual" butterflies, such as Polites thermistocles, Thymelicus lineola, Polites mystic, Phyciodes tharos, were abundant in all of these places. It appears then that garita is not extending eastward, but rather the populations in the Cloche area may represent relicts from a once more continuous distribution connecting with western populations. The apparent restriction of garita in the Cloche area to the natural alvars, areas with unusual native vegetation, further suggests relict status. Although much more study will be necessary to determine beyond any doubt the extent of the disjunction, it need not prevent some speculation concerning the manner in which such a disjunctive occurrence might arise, and whether or not it is indeed relict. Shapiro (1970) has suggested an eastward movement of Plebejus melissa samuelis Nabokov during the warmer and drier xerothermic period ca. 5,000 B.P. The alvar vegetation may have been more widespread during the xerothermic period, and some of the alvar plants in Manitoulin District are distinctly western (Catling et al., 1975). The occurrence of prairie chickens [7'ympanuchus czipido (Linnaeus)] on Manitoulin Island is another western feature of the area. Could garita be a xerothermic relict? This might explain eastern occurrences of the midwestern powesheik, but it does not seem an adequate explanation for the advent of an insect of an apparently cooler, more western and cordilleran environment. The disjunction of vascular plant species of the western cordillera in the upper Great Lakes region has already been alluded to. Frequently this disjunction pattern involves the Gaspe peninsula as well. Presumably these plants are relicts of a once continuous arctic and subarctic or at least cool temperate environment that existed in these latitudes across much of North America for a brief internal, perhaps several hundred years, as the 3Catling: On the Occurrence of Oarisma Garita (Reakirt) (LepidopteraPublished by ValpoScholar, 19776 2 THE GREAT LAKES ENTOMOLOGIST Vol. 10, No. 2 continental glaciers melted back northward ca. 9,000-10,OOOB.P. (Zoltai, 1968; Terasmae, 1968). The shorelines of the postglacial upper Great Lakes were continuous with Lake Agassiz to the west ca. 10,000 B.P. (Zoltai, 1968), and the gradually dropping water levels of these lakes exposing new land for colonization may have provided a corridor for the immigration of western fauna and flora that may have otherwise maintained its western distribution during the Wisconsin advance. The plants could have persisted as disjuncts in local areas where a cool environment was maintained. Although the Cloche area was inundated by glacial Lake Algonquin-Nipissing perhaps until 4,000 B.P. (Zoltai, 1968), other parts of Manitoulin District were gradually emerging and it is conceivable that garita existed in the immediate vicinity. isostatic rebound resulting in the continuing emergence of new limestone barren habitats, and later the maintainence of these as open habitats by periodic fire, drought, and fluctuating lake levels, and finally the perpetuation of a cool environment by the moderating effect of a large body of water, might have maintained a suitable habitat for garita since early postglacial times. If an appropriate environment were maintained in the area for 10,000 years, one wonders about the possibility of a gravid female wandering in or being blown in from the far west a number of times since then. Wagner (1972) has suggested long-distance spore dispersal by the prevailing winds from the west as one possible explanation for west to east disjunctions of homosporous vascular plants. Pieris protodice Boisduval and LeConte provides a good example of a butterfly species of the south and west that moves into local areas of southern Ontario, and establishes colonies for a few to several years, only to disappear when the ephemeral habitats with annual mustard species decline. However, this kind of wind blown or wandering disjunction seems unlikely with a local species of more or less stable habitats as garita appears to be. One must exercise caution in assuming natural disjunction. The likelihood of transport by man is difficult to evaluate. Who has n o t carried a bothersome bee or fly several miles in a car, and what entomologist has no t been impressed by the diversity of insects on the fronts of cars a t service centres along the highway? It does seem possible, although unlikely, that a gravid female could travel by vehicle from the far west and establish a colony in the east. A purposeful introduction seems even less likely. Is garita in the Cloche area disjunct 650 miles or more, and does this actually represent a postglacial relict? Are other insects disjunctive in this area? Definite answers will require more study of the Cloche area, and more information on the ecology and distribution of Oarisnla spp. elsewhere. The Cloche area is biologically unique and the Garita Skipper only adds to its unique quality, and a t the same time poses some most interesting questions. Hopefully some examples of the alvars in the Cloche area will be preserved for biological research, maintainance of unique genetic material, and for their unusual diversity of flora and fauna. DISPOSITION OF SPECIMENS AND ACKNOWLEDGMENTS Of eight specimens of garita collected in the Cloche area, two were sent to Dr. C. Don MacNeill of the Oakland Museum, California, two were deposited in the collection of the Department of Entomology at the Royal Ontario Museum, Toronto, and three are in the private collections of P. M. Catling, M. C. Nielsen, and W. H. Wagner. My thanks to Prof. Wagner for his critical reading, to Dr. MacNeill for confirming the identification of specimens, to Mr. Nielsen for his correspondence, and to Miss K. L. McIntosh for assistance in the field. LITERATURE ClTED Catling, P. M., J. E. Cruise, K. L. McIntosh and S. M. McKay 1975. Alvar vegetation in southern Ontario. Ont. Field Biol. 29:l-25. 4The Great Lakes Entomologist, Vol. 10, No. 2 [1977], Art. 4https://scholar.valpo.edu/tgle/vol10/iss2/41977 THE GREAT LAKES ENTOMOLOGIST 63 Holzman, R. W. 1972. Eastern range extension for Oarisma powesheik Parker (Lepidop- tera: Hesperiidae). Great Lakes Entomol. 5: 1 11-1 14. Irwin, R. R. and J. C. Downey 1973. Annotated checklist of the butterflies of Illinois. Ill. Nat. Hist. Surv. Biol. Notes 81. 60 p. Johnson, K. 1972. The butterflies of Nebraska. J. Res. Lepid. 11: 1-64. MacNeill, C. D. 1975. Hesperiidae, p. 423-578 in Howe, W. H., The butterflies of North America. Doubleday, N.Y. 633 p. McAlpine, W. S. 1972. Observations of the life history of Oarisma powesheik (Parker) 1870. J. Res. Lepid. ll:83-93. Munroe, E. 1968. Insects of Ontario: Geographical distribution and post-glacial origin. Proc. Entomol. Soc. Ont. 99:43-50. Riotte, J. C. E. 1970. Checklist of Ontario skippers and butterflies. Toronto Entomol. Assn., Occ. PubI. 1: 1-4. - 1971. Butterflies and skippers of northern Ontario. MidCont. Lepid. Series 2:l-20. 1972. On the distribution of some skippers in Ontario. J. Res. Lepid. 11:81-82. Shapiro, A. M. 1970. Postglacial biogeography and the distribution of Poanes viator (Hesperiidae) and other marsh butterflies. J. Res. Lepid. 9:125-155. Tasker, R. R. 1970. Further eastward extension of the range of Euchloe ausonides mqyi (Pieridae) in Ontario. J. Lepid. Soc. 24:226. Terasmae, J. 1968. A discussion of deglaciation and the boreal forest history in the northern Great Lakes region. Proc. Entomol. Soc. Ont. 99:31-43. Wagner, W. H. 1972. Disjunctions in homosporous vascular plants. Ann. Mo. Bot. Garden, 59:203-217. Zoltai, S. C. 1968. Glacial history of the upper Great Lakes. Proc. Entomol. Soc. Ont. 99: 15-20. 5Catling: On the Occurrence of Oarisma Garita (Reakirt) (LepidopteraPublished by ValpoScholar, 1977

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On the Occurrence of \u3ci\u3eOarisma Garita\u3c/i\u3e (Reakirt) (Lepidoptera: Hesperiidae) in Manitoulin District, Ontario

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