Great Basin Naturalist Volume 55 Number 1 Article 13 1-16-1995 Full Issue, Vol. 55 No. 1 Follow this and additional works at: https://scholarsarchive.byu.edu/gbn Recommended Citation (1995) "Full Issue, Vol. 55 No. 1," Great Basin Naturalist: Vol. 55 : No. 1 , Article 13. Available at: https://scholarsarchive.byu.edu/gbn/vol55/iss1/13 This Full Issue is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. T H E GREATR EAT BASINBAS I1 N naturalist A VOLUME 55 nigNIQ I1 JANUARY 19951995 BRIGHAM YOUNG university GREAT BASIN naturalist editor assistant editor RICHARD W BAUMANN NATHAN M SMITH 290 MLBM 190 MLBM PO box 20200 PO box 26879 brigham young university brigham young university provo UT 84602020084602 0200 provo UT 84602687984602 6879 8013785053801 378 5053 8013786688801 378 6688 FAX 8013783733801 378 3733 emailE mail nmshbllibyuedunmshbll1byuedu associate editors MICHAEL A BOWERS PAUL C MARSH blandy experimental farm university of center for environmental studies arizona virginia box 175 boyce VA 22620 state university tempe AZ 85287 J R CALLAIIANCALLAHAN STANLEY D smiSMITHTH museum of southwestern biology university of department of biology new mexico albuquerque NM university of nevada las vegas mailing address box 3140 hemet CA 92546 las vegas NV 89154400489154 4004 JEFFREY J JOHANSEN PAUL T TUELLER department of biology john carroll university department of environmental resource sciences university heights OH 44118 university of nevada reno 1000 valley road reno NV 89512 BORIS C kondratieff department of entomology colorado state ROBERT C WHITMORE university fort collins CO 80523 division of forestry box 6125 west virginia university Morganmorgantowntown WV 26506612526506 6125 editorial board berranjerran T flinders chairman botany and range science duke S rogers zoology william hess botany and range science H duane smith zoology all are at brigham young university ex officio editorial board members include steven L taylor college of biology and agriculture stanley L welsh director monte L bean life science museum richard W baumann editor great basin naturalist the great basin naturalist founded in 1939 is published quarterly by brigham young university unpublished manuscripts that further our biological understanding of the great basin and surrounding areas in western north america are accepted for publication subscriptions annual subscriptions to the great basin naturalist for 1995 are 25 for individual sub- scriscribersbers 30 outside the united states and 50 for institutions the price of single issues is 12 all back issues are in print and available for sale all matters pertaining to subscriptions back issues or other busi- ness should be directed to the editor great basin naturalist 290 MLBM PO box 20200 brigham young university provo UT 84602020084602 0200 scholarly exchanges libraries or other organizations interested in obtaining the great basin naturalist through a continuing exchange of scholarly publications should contact the exchange librarian 6385 HBLL PO box 26889 brigham young university provo UT 84602688984602 6889 editorial production staff joanne abel technical editor jan spencer assistant to the editor copyright 0 1995 by brigham young university ISSN 001736140017 3614 official publication date 16 january 1995 1951 95 750 12935 the great basin naturalist PUBLISHED AT PROVO UTAH BY BRIGHAM YOUNG university ISSN 001736140017 3614 VOLUME 55 31 JANUARY 1995 no 1 great basin naturalist ssi551 0 1995 appp 1 18 LIFE HISTORIES OF stonefliesSTONE FLIES plecoptera IN THE RIO CONEJOS OF SOUTHERN COLORADO R edward DeWaltdewalt12dewa1ti212 and kenneth W StewartStewartiartl1 ABSTRACT thirty one stonstoneflyefly species representing eight families were collected during the march 1987 to may 1990 study period genera represented by more than one species included capniaacapnia Utacapnia taenionematahtaemonemaTaeniTaeonemamonema Suwallia triznakatnznakaTriznaka Isogenisogenoidesoides and isoperla peak species richness was recorded on or near the summer solstice in 1988 and 1989 climatic differences between years were reflected in nymphal development and emergence phenology of most species new or important corroborative life history data are presented for 11 stonstoneflyefly species of this assemblage the hyporheichyporheic nymphal development of most chlorochloroperlidperlid species limited the number of early instarsmstars sampled and our capacity to interpret voltinism limited nymphal data suggested a univoltine slowsiow cycle for plumiperlaPlumiperla diversa frison adults of walliasuwalliaSu pallidulapallidula banks and S wardi banks were present for an extended summer period but the bulk of their respective emergence times was temporally separated isogenoidesIsogen oides zionensis hanson pteronarcella badia hagen and pteronarcys californicacalifornica newport were all shown for the first time to have a 9 lomo10 mo egg diapause and all three species have a semivoltmesemivoltine life cycle sawalaskwala americanaamencanaamencana klapalekklapdlekKlapalek and isoperlafulvaisoperla folva claassen were further confirmed to have univoltine slow cycles univoltine fasthast and univoltine slowsiow life cycles are reported for the first time in I1 phaleratephalerataphalerata and I1 quinquepunctatequinquepunctata respectively regression analysis revealed that six of the eight abundant species had extended emergence patterns slopes of ad5d while only two had synchronous patterns warmer spring and summer tempera- tures in 1989 increased the slopes for five of the eight species studied but did not change their synchrony designation nine of I111 I1 abundant species advanced their median emergence date in 1989 over 1988 this and the higher slope values are consistent with a hurried nymphal development and narrower emergence period due to the warmer thermal regime of 1989 key words plecoptera life history diversitybiobiodiversity life cycle rocky mountains Stonestonefliesflies plecoptera are one of the integral understood sheldon and jewett 1967 stewart and often dominant insect orders in stream and stark 1988 precise life histories are ecosystems therefore they are important as known for 5 of the more than 575 north biological indicators as fish food and as part american species and knowledge of stonstoneflyefly of the energy and nutrient economy of streams life histories and ecology in southern rocky stewart and stark 1988 taxonomy of the mountain streams is sparse this has limited north american fauna is now well known our ability to increase understanding of eco- however information on their life histories logical relationships between cohabiting stone local species richness and ecology is still poorly fly species in this region 1 departmentidepartment of biological sciences university of north texas denton TX 76203 2presentpresent address department of zoology and physiology louisiana state university baton rouge LA 70803 1 2 GREAT BASIN naturalist volume 55 one objective of this study was to deter- highway 17 and 4 km north of antonito at the mine richness of the stonstoneflyefly assemblage of colorado highway 285 bridge respectively the rio conejos of southern colorado a large stream temperatures varied from below drainage that has not been previously studied freezing during the winter months to near second we documented the important life 20c20gocgog C in august ice cover was common from history events of its dominant species for december through march snowbeltsnowmeltSnowmelt began which sufficient individuals and observations in april usually leading to peak flows in june could be gathered by intensive monthly sam- base flows were attained by late august and pling and by living streamside during spring continued through the winter water released and summer from platiroplatoro reservoir 48 km upstream aug- research was patterned after the classic mented river flow during summer low flow studies of harper 1973a 1973b and harper periods bottom substrates were characterized and hynes 1972 who studied a substantial by large boulders cobble gravel and sand portion of the eastern canadian fauna and these were covered by a thin layer of silt in addressed critical aspects of life histories such quiet water important organic substrates as egg development diapause and adult included the flooded coppicescoppicuscoppices of willows and behaviors that are often overlooked H B N cottoncottonwoodswoods and their entrained leaf packs hynes in an address to the international ple- willow salix sppapp cottoncottonwoodswoods and ashensaspens coptera symposium 1992 emphasized the populus sppapp and alder alnus sp con- need for more attention to these aspects to tritributed to the riparian corridor support the eventual development of a para- physical conditions digm of life history evolution within the ple- copteracoptera we have also adopted the approaches stream temperature was monitored at site of knight and gaufin 1966 harper and one from june through august 1988 using a ryan TM magnin 1969 sheldon 1972 barton 1980 continuous recording thermograph low ernst and stewart 1985a 1985b and high and mean daily stream tempera- from hassage and stewart 1990 in comparatively tures were calculated temperatures recorded at 0400 0800 1200 1600 2000 and studying an assemblage of species