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.     

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, II: factors influencing distribution

Biogeographic, flow regulation (water clarity and temperature), and temporal influences affect the composition of the chironomid midge assemblage in the Colorado River between Glen Canyon Dam and Lake Mead. This assemblage is dominated by euryecious Nearctic and Holarctic orthocladine taxa (23 of 38 total species, total weighted relative abundance [WRA] = 0.972) and includes a minor Neotropical component. Chironomid species richness increases over distance downstream from the dam, and dominance shifts across 3 turbidity segments. Eleven species occur in the cold-stenothermic Clearwater (CW) segment between the dam and the 1st perennial tributary (the Paria River, 26 km from the dam). Chironomid diversity increases from 18 to 24 species in the variably turbid (VT) and usually turbid (UT) segments downstream, respectively. Total Cricotopus spp. WRA is negatively correlated with distance (turbidity), white total Chironominae WRA shows the opposite pattern. In contrast to chironomid diversity, species density decreases from 0.42 species/km in the CW segment to 0.19 and 0.08 species/km in the VT and UT segments, respectively. Seasonal dominance shifts slightly from orthocladine Eukiefferiella spp. in winter (WRA = 0.101) to Cricotopus spp. (WRA = 0.165) in summer. Total WRA is lowest in spring (0.191). The assemblage is depauperate compared with other western rivers and has changed over post-dam time.     

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, I: systematics and ecology

We describe the chironomid midge fauna of the Colorado River between Glen Canyon Dam and Lake Mead, Arizona. This depauperate fauna, consisting of 38 species, is dominated by euryecious Nearctic or Holarctic orthocladine taxa. In addition, a small Neotropical faunal component is represented by Polypedilum obelos Sublette & Sasa and Rheotanytarsus hamatus Sublette & Sasa. The following new synonyms are given: Protenthes riparius Malloch 1915 with Tanypus bellus Loew 1866 [= Procladius (Psilotanypus) bellus (Loew)]; Cricotopus olivetus Boesel 1983 with Cricotopus (Circotopus) annulator (Goetghebuer) 1927; Cricotopus edurus Sublette & Sublette 1971 with Orthocladius infuscatus Malloch 1915 [= Cricotopus (Cricotopus) infuscatus (Malloch)]. The following new species are described: Cricotopus (Cricotopus) blinni Sublette, Cricotopus (Cricotopus) hermanni Sublette, Metriocnemus stevensi Sublette, and Cladotanytarsus marki Sublette. We discuss the distribution and ecology of each chironomid species in this large, regulated, aridlands river.     

A taxonomic revision of the genus Stempellinella (Diptera: Chironomidae)

The species of the chironomid genus Stempellinella are revised, described, and figured, and keys to known larvae, pupae, and male and female adults are presented. Five species new to science are diagnosed and described. An emended generic diagnosis of Stempellinella is given and morphological differences from its putative sister genus Zavrelia are discussed. The partial cytochrome oxidase subunit I (COI) gene sequences (DNA barcodes) of 10 Stempellinella species are presented and the variation in genetic distances within and between species is compared. The results indicate that DNA barcodes are suitable molecular markers for identification of Stempellinella species. The following life stages and species are diagnosed and described: the larva, pupa, male, and female of S. brevis, S. chambiensis, S. ciliaris, S. edwardsi, S. fimbriata sp. n., S. flavidula, S. leptocelloides, S. saltuum, and S. truncata; the pupa, male, and female of S. reissi and S. tamaseptima; the larva, pupa, and male of Stempellinella boltoni sp. n.; the pupa and male of S. lamellata sp. n.; the male and female of S. coronata; and the male of S. apicula, S. brevilamellae, S. distincta sp. n., and S. sublettorum sp. n. Two pupal types are described but not formally named. The following changes of combination are made: Stempellina chambiensis and Stempellina truncata are transferred to the genus Stempellinella. Zavrelia inopinata is listed as a new junior synonym of Stempellinella ciliaris.     

Capybaras (Rodentia: Cavidae) in highlands: environmental variables related to distribution,and herbivory effects on a common plant species

The capybara Hydrochoerus hydrochaeris is one of the largest and most widely distributed herbivores in the Neotropical lowlands. However, as yet, there are no records of its occurrence in highland environments. Our aim was to evaluate the environmental variables related to the capybara’s distribution and monitor the effects of its herbivory on the individuals and on the reproductive phenology of A. polyanthus, a common and important plant species of the high-altitude grasslands. Our results show that capybaras frequently occur in the high-altitude grasslands along the Campo Belo River, but they avoid waterlogged areas, occurring more frequently on the dry rocky areas. Capybara herbivory affected the number of A. polyanthus rosettes in flower, leading to the presence of inflorescence formation anomalies. High-altitude grasslands apparently provide capybaras with the three main components (food, shelter and water) required for their occurrence. However, although they seem to present a seasonal feeding strategy, which also happens in lowlands, their avoidance of the waterlogged areas suggests that in highlands the species may present different environmental preferences from those presented in lowlands. In addition, the impact of capybaras’ herbivory on A. polyanthus individuals indicates the potential impact that capybaras can represent on the plant community of the high-altitude grasslands. This appears to be a great opportunity to study the effect of the arrival of a large herbivore in a new environment and possible impacts on plant assemblages.     

Four new species of Platycephala with a key to the Chinese species (Diptera,Chloropidae)

The following four new species of the genus Platycephala from China are described: Platycephala apicinigra sp. nov., P. brevifemura sp. nov., P. lateralis sp. nov. and P. nanlingensis sp. nov. An updated key to the species of the genus Platycephala from China is presented.     

Diatom species composition and ecology of the Animas River Watershed, Colorado, USA

The diatom flora of selected sites in the Animas River Watershed, San Juan County, Colorado, was studied. Eighty diatom taxa were identified from 10 sites: 8 sites on the Animas River and 1 site each on the Cement and Cascade tributaries. The sample diatom abundance was dominated by Achnanthidium minutissimum , Encyonema silesiacum , Aulacoseira distans , Hannaea arcus , and Diatoma mesodon . The presence of teratologic specimens of Fragilaria and Achnanthidium in the samples indicated the possibility of metals contamination. Diatom diversity was low and Lange-Bertalot pollution index scores indicated little organic pollution evidenced from diatom composition. There was evidence that diatom composition at the sites was differentially affected by pH and possibly by the concentrations of Zn alone or in combination with Cd, Cu, and Fe.     

New species of Astragalus (Leguminosae) from Mesa County, Colorado

Named and described is Astragalus debequaeus Welsh from Mesa County, Colorado.         

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.     

Two new species of Hudsonimyia Roback, 1979 (Diptera: Chironomidae: Tanypodinae) from Neotropical Region unveiled by morphology and DNA barcoding

Two new species of Hudsonimyia Roback, 1979 Roback, SS. 1979. Hudsonimyia karelena, a new genus and species of Tanypodinae, Pentaneurini. Proc Acad Nat Sci Philadelphia., 131: 1–8. [Web of Science ®] , [Google Scholar] (Diptera: Chironomidae: Tanypodinae) are described and illustrated as male, pupa and larva. The generic diagnosis of pupa is emended and keys to males, pupae and larvae of known species are provided. The different life stages for one of the described species were associated by DNA barcodes.     

Stegana castanea species group (Diptera,Drosophilidae) from the Oriental region

The Stegana castanea species group is established as a morphological group within the subgenus Steganina, based on two known and six new species from the Oriental region: Stegana (Steganina) bacilla Chen and Aotsuka, 2004 Chen, HW and Aotsuka, T. 2004. A survey of the genus Stegana Meigen from southern Japan (Diptera, Drosophilidae). J Nat Hist., 38: 2779–2788. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]; S. castanea Okada, 1988 Okada, T. 1988. Family Drosophilidae (Diptera) from the Lund University Ceylon Expedition in 1962 and Borneo collections in 1978–1979. Entomol Scand (suppl)., 30: 109–149.  [Google Scholar]; S. (S.) reni sp. nov.; S. (S.) tiani sp. nov.; S. (S.) tongi sp. nov.; S. (S.) wangi sp. nov., S. (S.) weiqiuzhangi sp. nov. and S. (S.) xui sp. nov. from southern China. A key to all the species of this group is provided.     

Neotropical Lispe (Diptera: Muscidae): notes,redescriptions and key to species

The following species of the fly genus Lispe are redescribed: L. albitarsis (Stein, 1898), L. latana Snyder, 1949, L. levis (Stein, 1911), L. lisarba Snyder, 1949, L. nasoni (Stein, 1898), L. serotina Wulp, 1896, L. setuligera (Stein, 1911) and L. vilis (Stein, 1911). Additionally, a new diagnosis is proposed for L. rufitibialis Macquart, 1843, and in order to fix the identity of the name the lectotype is designated. To facilitate species identification, a pictorial key for the species of Lispe in the Neotropical region and distribution maps are presented, together with the first published illustrations of the male terminalia of L. latana, L. levis and L. lisarba, and the female of L. lisarba.     

Occurrence of native Colorado River cutthroat trout ( Oncorhynchus clarki pleuriticus ) in the Escalante River drainage, Utah

Field surveys were conducted during 1997 and 1998 documenting the distribution and abundance of Colorado River cutthroat trout ( Oncorhynchus clarki pleuriticus ) in Escalante River tributaries. This documented occurrence of native trout in the Escalante River drainage of southern Utah represents an expansion of the known historic range of this subspecies as reported before the 1990s. We found 5 populations of native trout ranging in biomass from 3.0 to 104.2 kg ha -1 and occupying 13.2 km of stream of 130 km of estimated historic habitat. Current distribution and abundance of Colorado River cutthroat trout were compared to early introductions of nonnative trout stocked for sport fishing purposes. Native cutthroat trout have been displaced by nonnative cutthroat trout ( O. c. bouveri ), rainbow trout ( O. mykiss ), brook trout ( Salvelinus fontinalis ), and brown trout ( Salmo trutta ) except where they were isolated by physical or biological barriers. Displacement may have been more extensive except for the remoteness of the drainage and relatively recent introductions of nonnative trout. These conditions limited the overall amount of the drainage stocked, numbers of nonnative trout stocked, and time over which stocking occurred. Discoveries of native trout populations within the Escalante River drainage have allowed expanded conservation of this subspecies by adding new populations to what was known to exist and by increasing the known natural range of this fish.     

New species of oribatids from western Colorado (Acarina: Cryptostigmata, Suctobelbidae)

A new species of Suctobelba, S. tumulata, and a new genus and species, Parisuctobelba septenia, are described from collections of oribatids taken in coal strip-mining spoil banks near Hayden, Colorado. The new species are compared with members of the family from North America and Europe. The new genus is differentiated by a smooth, narrowed sensillum and seven pairs of genital setae. Taxonomic and ecological data are also discussed.     

A new species of Plecia from the Green River Formation and new combinations of fossil Bibionidae (Diptera)

Plecia akerionana , n. sp., is described from the Green River Formation, Colorado, and diagnosed with P. minutula Rice, P. myersi Peterson, and P. rhodopterina Cockerell. Plecia intermedia (Scudder), the genotype of Mycetophaetus , and Plecia creedensis James are transferred to the genus Penthetria , and Hesperinus immutabilis Melander is transferred to Plecia .     

Two new species of the subgenus Cacoxenus (Nankangomyia) from the Oriental Region (Diptera,Drosophilidae)

Two new species of the subgenus Cacoxenus (Nankangomyia) Máca and Lin, 1993 Máca, J. and Lin, F. J. 1993. The Drosophilidae of Taiwan: genera Amiota (excluding subgenus Phortica) and Leucophenga (Nankangomyia subg. nov.).. Bulletin of the Institute of Zoology, Academia Sinica, 32: 1–11.  [Google Scholar] are described: C. (N.) gani sp. nov. from southwest China and C. (N.) unipaxillus sp. nov. from Myanmar. The diagnosis of Nankangomyia is revised.     

Descriptions of the Patagonian species of the subgenus Trichohelea of Forcipomyia,with a key to the Neotropical species (Diptera: Ceratopogonidae)

The following two new species of Forcipomyia (Trichohelea) collected in the Nothofagus patagonian forest are described and illustrated: F. (T.) sayhuequei from the province of Chubut in Argentina and Llanquihue in Chile, and F. (T.) tehuelche from the Argentinean province of Santa Cruz. Based on the examination of the types, the previously known species Lasiohelea shannoni Ingram and Macfie is recognized as a junior synonym of Forcipomyia limnetis Ingram and Macfie, and the species is redescribed and illustrated. A key to recognition of females and males of the 14 Neotropical species of the subgenus is included.     

Description of new Ceratitis MacLeay (Diptera,Tephritidae) species from Africa

As an addition to earlier published systematic revisions of the genus Ceratitis MacLeay, five new species are hereby described: Ceratitis (Pardalaspis) millicentae sp. n., C. (Ceratalaspis) oraria sp. n., C. (C.) perisae sp. n., and C. (C.) perseus, sp. n. all from Kenya, and C. (C.) ealensis sp. n. from the Democratic Republic of Congo. Their relationship with closely allied species within the respective subgenera is discussed and differentiating characters given.     

The effect of elevation on the distribution of sibling species in the Simulium arcticum complex (Diptera: Simuliidae)

At least 5 sibling species and an additional 11 cytotypes of the Simulium arcticum complex occur in Montana. Consequently, this speciose complex might allow study of environmental correlates with genetic differentiation. We used conventional methods of collection and cytogenetic analysis to study 1128 male larvae of the Simulium arcticum complex at 15 sites within 5 drainages in western Montana to test the hypothesis that distribution of siblings is associated with elevation. We sampled at the mouth, at the headwaters, and at an intermediate site to span the range of elevations within each drainage. We restricted our analyses to the most abundant taxa of the S. arcticum complex within our study area and observed a statistically significant presence of S. apricarium at low-elevation sites. Simulium arcticum IIL-18 appeared more frequently than expected at high elevation sites. Simulium brevicercum and S. arcticum sensu strictu appeared to be distributed randomly. We suggest potential causal reasons for these distributions including differential use of habitats along these elevational gradients.