The stoneflies (Plecoptera) of Louisiana

A list of species, illustrated keys to nymphs and adults, distribution, and biological notes are presented for 24 stonefly species occurring in Louisiana. Leuctra moha?, Pteronarcys dorsata, Helopicus subvarians, Paragnetina kansensis, Paragnetina immarginata, Phasganophora capitata, and Acroneuria evoluta are recorded only from the florida parishes east of the Mississippi River. Isoperla Coushatta, Isoperla mohri, Neoperla clymene, an undescribed Neoperla (Sp. A), Paragnetina fumosa, Acroneuria abnormis, Acroneuria arenosa, Perlinella drymo, and Perlesta placida are found both east and west of the Mississippi; and Allocapnia granulata, Allocapnia malverna, Amphinemoura nigritta, and three species of Taeniopteryx have been recorded only west of the Mississippi. Habitats are primarily sand-bottomed streams of pine-hardwood rolling hills, constituting a portion of the western Gulf Coastal Plain. Few stoneflies occur in streams of the Mississippi Alluvial Plain, the Alluvial Atchafalaya Basin, or the lowlands along the Red River.     

Records of stoneflies (Plecoptera) from Nevada

Distributional data are presented for 13 species of Nevada stoneflies including eight species new to the state list. A checklist of 30 species confirmed for Nevada is included.     

Winter stoneflies (Plecoptera) of New Mexico

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Twenty-two species of winter emerging Plecoptera were collected in New Mexico from 1979 to 1982. Distributional records are given for 13 that are new state records, including 2 new species, and 9 previously reported species.       

New records of stoneflies (Plecoptera) from New Mexico

Distributional data are presented for 30 species of New Mexico Plecoptera including 8 species new to the state list. Previously, many of the included species were known from a single location in the state. A revised checklist of 46 confirmed species is presented for the state.     

Zoogeographic affinities of the stoneflies (Plecoptera) of the Raft River Mountains, Utah

We examined faunal affinities of the Raft River Mountains using stoneflies (Plecoptera) as indicators. This island-like mountain range is isolated from other major mountain ranges in the Intermountain West by low-elevation, arid regions. Thirty-seven species were recorded from collections from 19 sites in the Raft River Mountains. Cluster analysis demonstrated the Raft River Mountain stonefly assemblage to be most similar to faunas of the Sawtooth and Wasatch mountains, and quite different from that of the Sierra Nevada. An analysis of the distribution patterns of each species, on a family-by-family basis, showed that the Raft River Mountains fauna consists mostly of species widespread in western North America. Most families were represented by at least 1 species whose distribution supports faunal affinities with regions to the north and west. Logistic regression of 6 long-distance dispersal factors against stonefly presence-absence data did not support long-distance dispersal as a viable means of colonization for the Raft River Mountains. This suggest that stonefly distribution patterns may be attributed to expansion and subsequent vicariance of suitable stonefly habitats during Pleistocene climatic oscillations.     

North American stoneflies (Plecoptera): systematics, distribution, and taxonomic references

A list of 537 Nearctic stonefly species is provided and distributions of all species are given by U.S. state and Canadian province. The list includes a bibliography of systematic and biogeographic papers published since the Zwick (1973) catalogue.     

Food and habitat relationships of Claassenia sabulosa (Plecoptera: Perlidae) in the Upper Colorado River, Colorado

Streambed surveys were conducted along the upper Colorado River, Colorado, to describe the distributions of Claassenia sabulosa larvae in relation to current speed and to determine their diets. We also addressed diel feeding periodicity by sampling during both day and night. Claassenia sabulosa was more abundant in riffle habitats than in runs. A positive relationship existed between C. sabulosa abundance and stream current, with larval size increasing with current speed. Chironomidae, Baetidae, and Simulidae collectively accounted for 93% of the prey found in stonefly guts; however, these categories were not consumed equally by all C. sabulosa . Smaller C. sabulosa primarily ate chironomids, and larger individuals consumed more baetids. Only a slight difference existed in the percentage of empty guts between night- and day-collected stoneflies, and ranges of prey per gut at night were higher than those in the day, suggesting that these stoneflies may forage more intensively at night.     

Emergence patterns of large stoneflies (Plecoptera: Pteronarcys, Calineuria, Hesperoperla ) in a Montana river

Emergents of Pteronarcys californica, Calineuria californica , and Hesperoperla pacifica were captured with replicated emergence traps at 3 sites along the banks of Rock Creek, Montana. Pteronarcys emergence in early June was short (88% of individuals in 6 d) and attained rates of 5 m -1 d -1 (shoreline distance) and cumulative densities up to 19 m -1 yr -1 . Calineuria emerged synchronously (89% in 9 d) 2 wk later at densities up to 7 m -1 d -1 and 40 m -1 yr -1 . The less numerous Hesperoperla (5 individual m -1 yr -1 ) had a longer emergence period partially coinciding with Calineuria Median males of Pteronarcys and Calineuria emerged 2-3 d before median females; protandry was not significant Hesperoperla . Sex ratios were female-biased in Pteronarcys and Hesperoperla but male-biased in Calineuria . Size trends through emergence were very weak although females showed a greater tendency towered larger size early in emergence.     

Calileuctra , a new genus, and two new species of stoneflies from California (Plecoptera: Leuctridae)

Calileuctra is proposed as new genus in the family Leuctridae, with Calileuctra ephemera designated as the type species. All stages of Calileuctra ephemera are descpribed. Calileuctra dobryi is described in the male and female stages. Both species inhabit Mediterranean climatic region of California. A phylogenetic analysis of the genera in the family Leuctridae is given, which places Calileuctra near the genus of Perlomyia .     

Life strategies in the evolution of the Colorado squaqfish ( Ptychocheilus lucius )

The Colorado squawfish, a large predaceous cyprinid, is a generalist species adapted to the large seasonal water fluctuations, low food base, and changing riverine subsystems of the Colorado River. Extant at least as early as the Miocene epoch, Ptychocheilus has survived by incorporating life strategies to deal with changing climates varying from arid to pluvial. Migration and long-term movement patterns appear to have evolved as tactics to perpetuate a grand reproductive strategy for exploiting the changing habitats and general environmental conditions of the late Cenozoic era. Accordingly, high mobility of a large fish would aid in selection of optimum spawning, nursery, and adult habitats in the dynamic lacustrine/riverine system that existed at that time. A spatial separation of life stages thus produced would aid in the reduction of intraspecific competition. Large size, long life, and late spawning of Ptychocheilus indicate that mortality of young must be disproportionately high compared to that of the adult form. Growth to a large size should reduce predation by other fishes and, once attained, would facilitate long distance movement for reproduction, feeding, and other purposes. Such a strategy, formerly highly adaptive, may now be implicated in the decline of this species in controlled riverine systems.     

Changes in riparian vegetation along the Colorado River and Rio Grande, Colorado

Changes in vegetation including area occupied, canopy cover, and maturity class of cottonwoods ( Populus spp.) within lower-elevation zones of the Colorado River and Rio Grande in Colorado were monitored over 25- and 27-year intervals, respectively, using photo-interpretative methods. Estimated loss of cottonwoods along the Colorado River was 2ha/km (-17.5%), and remaining stands had become more open and older. Cottonwoods along the Rio Grande increased 1.6 ha/km (9.3%) with minor canopy cover and maturity class changes. Area occupied by shrubs and river channel changed little along the Colorado River, but declined along the Rio Grande. Loss of hay meadow occurred along both rivers, whereas developed land increased along the Colorado River and farmland increased along the Rio Grande. Wildlife habitats along the Colorado deteriorated much more rapidly than those along the Rio Grande during monitored intervals.     

New Nearctic Chloroperlidae (Plecoptera)

Alloperla furcula, A. hamata, A. roberti and Triznaka spinosa are described from North America. A new genus, Bisancora, based on the new species B. rutriformis, is described and includes B. pastina (Jewett). Alloperla quadrata is synonymized with A. leonarda Ricker.     

Three new species of Nearctic Isoperla (Plecoptera)

Nymphs and adults of three new species of Isoperla are described from reared material. I. sagittata is known only from southeastern Texas, I. Coushatta has been collected in East Texas and Oklahoma, and I. jewetti occurs in the Basin and Range Mountains of West Texas. The male aedeagii, female subgenital plates, and nymphal mouthparts are diagnostic in all three species.     

A review of the genus Soliperla (Plecoptera: Peltoperlidae)

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} The western Nearctic stonefly genus Soliperla is reviewed and six species are recognized. Soliperla sierra (Calif.) and S. tillamook (Ore.) are described as new to science and illustrations of diagnostic features are presented for all species. Males and nymphs are keyed and a phylogeny for the group is proposed.       

Plecoptera and Trichoptera species distribution related to environmental characteristics of the metal-polluted Arkansas River, Colorado

The Upper Arkansas catchment has been polluted with heavy metals from mining for almost 140 yr. Adult Plecoptera and Trichoptera species distributions were recorded from 22 stations along 259 km of main river during 1984-85 so that these could be related to metal deposition and other environmental characteristics. Chemically or physically perturbed sites had poor species richness compared with adjacent sites. There was no sequential downstream increase in species numbers. Filter-feeders proportionally increased downstream as predators declined; these proportions were reset at a high-energy site before the trend resumed. Using canonical correspondence analysis, we found that species composition was most strongly related to changes in distance/altitude and to temperature, particularly after regulatory flows entered the river. The proportion of biological variation explained by river measurements indicated that collected adults were largely derived from the main Arkansas River. Species tolerant of high sedimentary metal concentrations were identified while some other species appeared to be sensitive. The study provides a disturbed-state reference for monitoring effects of remedial actions begun in 1991, and for comparisons with other Colorado rivers.     

Two new species of Chloroperlidae (Plecoptera) from California

Suwallia sierra and Sweltsa pisteri are described as new species in the family Chloroperlidae from California, USA. Illustrations of the male terminalia of both species and the female and egg of S. sierra are presented. In addition, detailed figures of the epiproct of 2 similar species, Sweltsa townsei and Sweltsa resima , are included. Diagnoses provided comparing the new taxa with related species. Observations indicate that S. sierra may belong to the same clade as the genus Neaviperla .     

Sexual dimorphism in malpighian tubules of Pteronarcys californica Newport (Plecoptera)

The Malpighian tubules in female nymphs and adults of Pteronarcys californica Newport are larger and whiter than in males. This difference is detectable in nymphs as small as 300 mg in live weight (final instar nymphs weigh 800 to 1600 mg depending on sex), and is most pronounced in late nymphs and adults. These differences are thought to be related to the increased excretory load imposed by the synthesis of ooplasm in the late female nymph and adult.         

Stoneflies (Plecoptera) of Mount Rainier National Park, Washington

Mount Rainier National Park, with an area of 95,356 ha, is approximately one-third as large as the state of Rhode Island. The lowest point is 490 m in elevation in the southeastern corner near where the Ohanapecosh River crosses the southern boundary. Columbia Crest is the highest point at 4392 m. The entire park is a rugged landscape marked by the major topographical feature, Mount Rainier, comprising over 25,899 ha, almost one-third of the park. The park lies entirely west of the crest line of the Cascade Range. Most streams in the park originate on Mount Rainier; however, several large rivers meander through the park near its boundaries. One of the first attempts to summarize the stoneflies of Washington, including Mount Rainier National Park, was Hoppe's 1938 work that reported ca 8 species. Jewett (1959) reviewed the stoneflies of the Pacific Northwest and listed 7 species that had type localities in the park: Megaleuctra kincaidi Frison, Doddsia occidentalis (Banks), Soliperla fenderi ( Jewett), Frisonia picticeps (Hanson), Isoperla rainiera Jewett, Megarcys irregularis (Banks), and M. subtruncata (Hanson). Subsequently, Kathroperla takhoma Stark and Surdick (1987) was described from the park. Samples of adult stoneflies from 1994 to 2001 indicate the presence of at least 82 species, with 64% of these typical Pacific Northwest species, and 30 species, or 36%, widespread western North American species. Seventeen new Washington state records are listed, including a substantial range extension for Lednia tumana (Ricker). One undescribed species in the Sweltsa borealis complex was also discovered. We also present illustrations of male terminalia for Despaxia augusta (Banks) and Moselia infuscata (Claassen) to aid in the identification of these species.     

The life cycle of Hydroperla crosbyi (Plecoptera: Perlodidae)

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Hydroperla crosbyi in Texas exhibited a univoltine, fast life cycle over the three - year study period. Adults emerged in February – March when mean daily stream temperature reached ca. 15 C. Reared females in the lab deposited up to three egg masses. Mean fecundity of dissected females was 787 eggs/female. Oviposition in the field was observed and described. Eggs were triangular in cross section, brown, and measured 400 µ m × 535 µ m. They underwent an ca. seven-month diapause until mean daily stream temperature decreased to 18 C. Eyespots appeared, and hatching followed in two to three weeks. First instar nymphs were measured and described. Male and female nymphs underwent 12 and 14 instars, respectively, and could be sexed by the sixth. Fast growth occurred in the coldest season and Simuliidae and Chironomidae larvae were preferred food throughout development. Eggs contained a mean of 6.21 cal/mg. Ash - free mean caloric value of last instar nymphs was 6.0 cal/mg. Adult males and females lost 33.8 percent and 57.6 percent, respectively, of their caloric pool through their ca. 12 days of life.