Crispin S. Guppy - March 31, 2002
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Living Landscapes - Past, Present & Future BUTTERFLY INVENTORY OF THE UPPER FRASER RIVER BASIN Crispin S. Guppy - March 31, 2002 Arthropods are animals with an external (rather than internal) skeleton and jointed legs. They include the insects, springtails, centipedes, millipedes, sow bugs, amphipods, spiders, mites, ticks, scorpions, and various smaller groups. There are about 70,000 species of insects and other terrestrial and fresh water arthropods in British Columbia, 10-20% of which have never been recorded from BC and many of which have never been scientifically described. These species range from microscopic mites living between grains of soil to large butterflies that fly thousands of miles in their life-span. The exact number is unknown, because the presence of many species has yet to be documented. The undocumented species are primarily species known from elsewhere in North America, but also include hundreds of species new to science. Butterflies are the most well documented insect group, and yet we still have insufficient information about many species to know whether their populations are stable, increasing or decreasing. The research required involves the collection of samples over many years in very large areas. Many people express the opinion that collecting of butterflies is no longer required, because “everything is known about butterflies”. For example: “I do not see that anything of consequence remains to be done, either in North America or Europe, with the butterflies, except to study their life-histories. Both continents have been well explored, and only now and then can a new species be found. … the study of the life history requires no special training. Anyone can take it up and follow it with a pleasure that rapidly becomes absorbing.” (Edwards 1884) The author of this statement was William Henry Edwards, the greatest expert on North American butterflies in the late nineteenth century. Despite his expertise, his statement was wrong, because there was (and is) still a tremendous number of butterfly species and subspecies to document in North America. The book Butterflies of British Columbia (Guppy and Shepard 2001) recognised 187 species and 264 subspecies in BC. An astonishing 48% of the subspecies have been described and named since Edwards declared that everything was known about butterflies except life-histories. Eleven of the subspecies were named in 2001 in Butterflies of British Columbia. However, Edwards was correct in suggesting that the study of life histories is very rewarding, very little is known of the life histories of the butterflies in the Central Interior of BC. Most of what is known was discovered elsewhere in the world, and there is no certainty that the information is applicable for this area. There are still a number of subspecies remaining unnamed in BC, mostly in the Central Interior and the Peace River. This purpose of this project was to gather sufficient information to describe and name some of these unnamed subspecies, and to further document where each butterfly species and subspecies occurs in the Upper Fraser River Basin (north, east and west of the junction of the Chilcotin River with the Fraser River). To complete this project will take many more years, because of the huge area involved. This project is one step in the acquisition of knowledge of the butterflies of this area. It has been supported by the Royal British Columbia Museum (Government of British Columbia) program titled “Living Landscapes: Upper Fraser Basin – Past, Present and Future”. Royal British Columbia Museum 1-250-356-7226 675 Belleville Street 1-888-447-7977 Victoria, British Columbia CANADA http://livinglandscapes.bc.ca Living Landscapes - Past, Present & Future Butterflies are small, and many are sedentary; many populations inhabit areas of a hectare or less. They do not always require large areas of suitable habitat, even small patches can be important. However some species, such as swallowtail butterflies, require large breeding areas because they fly a considerable distance between laying each egg or small group of eggs. Finding even a representative sample of these populations, so as to understand the overall range in which each butterfly species occurs, requires a sustained sampling effort. A recent project to inventory butterflies and moths near Riske Creek in the Chilcotin lasted two years, and collected a total of 29,689 identified specimens from 623 light trap and aerial net samples. There were 59 field days with an average of 10.6 samples per day. The total inventory cost was $95,000. A collection of each species was deposited in the Royal British Columbia Museum, and other specimens were distributed to the Canadian National Collection of Insects and Arthropods and other collections. A total of 45 species of butterflies and 473 species of the larger moths were found, and several hundred species of very small moths were never sorted and identified due to insufficient funding. Forty rarely seen moth species were recorded, including several specimens of one species that was previously known in the world only from a single male. The cost and intensity of the inventory, which produced presence/absence data and a correlation with habitat types for each species, are typical of what is required for inventory of butterflies and moths in northern BC. In this Living Landscapes project I restricted my research to butterflies, to reduce the costs in time and money. I inventoried butterflies throughout much of the Upper Fraser River Basin during the summer of 2001, travelling about 5,000 km by car. I also spent three days in Burns Lake in October 2001, assisting with RBCM public programming, and I will spend another three days of public programming in Quesnel in the spring of 2002. I also presented slide shows on butterflies to the Prince George Naturalists, the Annual General Meeting of the Federation of BC Naturalists in Williams Lake, the Quesnel Naturalists, the North Quesnel Neighborhood Association; and the Quesnel Garden Club. There were several notable findings, including: Thicket Hairstreak (Mitoura spinetorum) – I found two specimens west of Riske Creek, which is the second record from the Cariboo-Chilcotin. The other nearest records were Lillooet, Valemont, and Pine Pass. This is the second record from the Upper Fraser River Basin. European Skipper (Thymelicus lineola) – I recorded this species from a highway ditch west of Vanderhoof. It is an introduced European pest of timothy hay crops. This is the first record from the Upper Fraser River Basin. Western Elfin (Incisalia iroides) – an undescribed subspecies occurs only in the central interior. I greatly expanded its known distribution during this project (south to near 100 Mile House, north to near Fort St. James). I am currently writing a formal scientific paper to name this subspecies. Square-spotted Blue (Euphilotes battoides) – an undescribed subspecies from the Chilcotin. This subspecies appears to have a world distribution limited to a very small area near Riske Creek. I greatly increased my sample size of this subspecies, so that now that I have a reasonable sample size. I am describing and naming this subspecies. There are three other specimens of this subspecies in the collection of Norbert Kondla; otherwise I have all known specimens. The Jutta Arctic (Oeneis jutta), the Dorcas Copper (Epidemia dorcas), and the Atlantis Fritillary (Speyeria atlantis) have all been thought to be rare in the Central Interior. My collecting over the last several years, including this year, has shown that all three species are abundant and widely distributed in wetland habitats. The Jutta Arctic appears to be an unnamed subspecies, however I still need additional specimens to be certain of this. Royal British Columbia Museum 1-250-356-7226 675 Belleville Street 1-888-447-7977 Victoria, British Columbia CANADA http://livinglandscapes.bc.ca Living Landscapes - Past, Present & Future Common Branded Skipper (Hesperia comma) – an apparently unnamed subspecies, or perhaps distinct species, was discovered near Quesnel during this study. Further collecting and study is needed before it can be named. Butterflies in the genus Pieris were collected for systematic (DNA) study by other researchers. In addition butterflies were collected for DNA comparative studies of the family Lycaenidae, the genus Limenitis, and the genus Polygonia. Scientific papers will be published by researchers elsewhere in the world, over the next few years, using data from these specimens. Voucher specimens and associated data from this project are deposited in the entomology collections of the Royal British Columbia Museum in Victoria. A pictorial summary of the 97 species of butterflies of the Upper Fraser River Basin follows, with a summary of the new information gathered as part of this project. For further information on each butterfly please consult Butterflies of British Columbia (Guppy and Shepard 2001 – see the reference list below). Skippers, Family Hesperiidae Latreille, 1809 1. Northern Cloudywing, Thorybes pylades pylades (Scudder, 1870) Notes for the Upper Fraser River Basin Generally distributed south of Hwy 16, also occurs in the Robson Valley. Fly May to July. Inhabit low elevation natural meadows and open forests. Caterpillars feed on clover and other wild legumes. Male upper side Royal British Columbia Museum 1-250-356-7226 675 Belleville Street 1-888-447-7977 Victoria, British Columbia CANADA http://livinglandscapes.bc.ca Living Landscapes - Past, Present & Future 2. Dreamy Duskywing, Erynnis icelus (Scudder & Burgess, l870) Notes for the Upper Fraser River Basin Generally distributed south of Hwy 16, also occurs in the Robson Valley. Fly May to mid-July. Inhabit low elevation natural meadows and open forests. Caterpillars feed on willows. Male upper side 3. Persius Duskywing, Erynnis persius (Scudder, 1863) Notes for the Upper Fraser River Basin Generally distributed south of Hwy 16. Fly May to July. Inhabit low elevation natural meadows and open forests. Caterpillar foodplants are unknown for our area.