New species and records of North American Pityophthorus (Coleoptera: Scolytidae), Part IV: the Scriptor group

Six new species of Pityophthorus from Mexico are described. The new species, all in the Scriptor group, are: atkinsoni, diminutivus, equihuai, thamnus, trunculus and zexmenivora . An additional locality record for P. coronarius Blackman is included. A new key to the 22 species included in the Scriptor group is presented.         

New species and new records of North American Pityophthorus (Coleoptera: Scolytidae), Part V: the Juglandis group

Six new species of Pityophthorus from Mexico are described. The new species, all in the Scriptor group, are: atkinsoni, diminutivus, equihuai, thamnus, trunculus and zexmenivora . An additional locality record for P. coronarius Blackman is included. A new key to the 22 species included in the Scriptor group is presented.         

Sexual selection and mating system variation in anuran amphibians of the Arizona-Sonoran Desert

Mating system variation in anuran amphibians of the Arizona - Sonoran Desert was reviewed. Male density and breeding period duration were negatively correlated in seven bufonids and pelobatids. Variation in male mating behavior and ability of females to freely select their mates unhindered by active - searching males also was related directly to male density. These observations support hypotheses relating ecological factors to mating system organization. It is suggested that male calling behavior, and anuran lek mating systems in general, may be significantly influenced by predation on vocalizing males.           

Annotated key to Eriogonum (Polygonaceae) of Nevada

Seventy - three species of Eriogonum (Polygonaceae) are reported for Nevada. A key is provided for the identification of these species along with brief notes on their distribution in the state and elsewhere.         

The identity of Bocourt's lizard Eumeces capito 1879

Eumeces capito Boucourt, 1879, is a senior synonym of Eumeces xanthi Günther, 1889. No exception to application of the Law of Priority is recommended in this case. The type locality of E. capito as originally published (“La côte oriental des Etats - Unis”) is erroneous. Undoubtedly the correct locality is China, but it is not restricted at present.         

High rates of photosynthesis in the desert shrub Chrysothamnus nauseosus ssp. albicaulis

  Basic aspects of photosynthesis were investigated in white rubber rabbitbrush ( Chrysothamnus nauseosus (Pallas) Britt. ssp. albicaulis ), a common C 3 deciduous shrub native to arid regions of the western U.S. Under favorable field conditions, net photosynthesis (P n ) ranged from 36 to 73 mgCO 2 · dm – 2 · hr – 1 , which is relatively high for a woody species. The leaves from the actively growing flowering shoots exhibited higher P n than those on the vegetative shoots. P n also varied according to the age of the leaves and the location of the plants. P n did not light saturate even at quantum flux densities (QFD) equivalent to full sunlight. The light compensation point was relatively high (ca 100 μ mol · m – 2 · S – 1 ), perhaps due to the presence of a tomentose vestiture on the leaf surface. At high QFD's, the stomatal conductance was high (ca 520 mmol · m – 2 · s – 1 ) for a woody species. RUBP - carboxylase content of the leaves ranged from 20 to 22 mg per gram F.W., which is similar to that found in most C 3 crop species. These results suggest that rabbitbrush is able to maintain high rates of P n , at least under nonstressed conditions.           

Use of biomass predicted by regression from cover estimates to compare vegetational similarity of sagebrush-grass sites

Regressions between vegetational cover, estimated with a two - tiered, gridded sampling frame, and biomass were used to obtain predicted biomass values from cover values. Comparisons of eight sites based on predicted biomass data and comparisons of the sites based on cover data indicate that predicted biomass data may better identify differences among sites. Also, some suggestions are made regarding the methods of using cover - biomass regressions to obtain predicted biomass values.         

Aspects of the biology of the flathead chub ( Hybopsis gracilis ) in Montana

Mature flathead chubs ( Hybopsis gracilis ) were present in mid - July and mid - August collections from the Musselshell River, Montana. The estimated numbers of mature eggs present in eight females were 360–753 per female. The smallest mature female and male collected were 113 and 123 mm in total length, respectively. The male to female sex ratio in collections was about 1:1. Only small differences were detected among the length – weight relationships of males and females and samples taken from various seasons and localities in Montana. Observations on size groups, fish associates, and habitat characteristics of flathead chubs are presented.         

Symbos cavifrons (Artiodactyla: Bovidae) from Delta County, Colorado

A partial cranium belonging to the extinct woodland musk - ox, Symbos cavifrons, is reported from the headwaters of Oak Creek, Delta County, Colorado. This is the first cranium of the genus Symbos to be described from the Colorado Plateau, and it helps to define the southwest boundary of the known range of the genus.         

Patterns of macroinvertebrate colonization in an intermittent Rocky Mountain stream in Utah

Colonization of macroinvertebrates in a headwater mountain stream was monitored using basket and Surber samplers. Taxa showed differences in colonization ability based both on dispersal ability and feeding strategy. Collector - gatherer feeding groups that could actively enter the water, i.e., Baetis mayflies, were the first organisms to colonize bare or new substrate. The slowest colonizers were heptageniid mayflies that colonized primarily from upstream migration. All organisms examined increased drifting behavior in response to decreases in discharge.         

Winter preference, nutritive value, and other range use characteristics of Kochia prostrata (L.) Schrad

A cafeteria - style study was conducted during the winter for two years with tame mule deer to determine if there were preferential differences between accessions of forage kochia ( Kochia prostrata ). Deer consumed significantly more of P.I. numbers 314929, 330708, and 356826 than any of the other accessions. Other plant adaptive characteristics and nutritive qualities are also reported.         

Age, growth, and food habits of tui chub, Gila bicolor, in Walker Lake, Nevada

At Walker Lake, Nevada, tui chub were collected 1975–1977 for analysis of age, growth rate, and food habits. The fork length (FL) – scale radius (SR) relationship was linear and described by the equation FL = 4.44 + 3.17 (SR). Age I, II, III, and IV chub were 116, 176, 218, and 242 mm fork length, respectively. Maximum longevity was six years. The length weight relationship was defined by the log transformed linear equation log weight = - 4.65 + 2.93 (log FL). Chub collected from pelagic regions ate mostly zooplankton, whereas chub collected from littoral areas had a diet of zooplankton and benthic organisms.         

Helminth parasites of the white-tailed jackrabbit, Lepus townsendi, from northwestern Colorado and southern Wyoming

Helminth parasites of white - tailed jackrabbits, Lepus townsendi , were surveyed from southern Wyoming and northwestern Colorado. A total of eight helminth species were identified, including two species of adult cestodes, Mosgovoyia pectinata and M. varabilis ; three species of larval cestodes, Multiceps serialis , Taenia pisiformis , and Taenis sp. ; and three species of nematodes, Dermatoxys veliger , Passalurus ambiguus , and a filariid, Micipsella brevicauda . In addition, eggs of an unidentified species of Nematodirus were found in pooled fecal samples. The cysticercus larva of Taenia sp. is a species new to science and will be reported elsewhere. Mosgovoyia varabilis and Micipsella brevicauda are new records for the white - tailed jackrabbit.         

New species of Astragalus (Leguminosae) from southeastern Utah

Named and described is Astragalus piscator Barneby & Welsh, a species of sect. Argophylli subsect. Missourienses. The species occurs in Grand and San Juan counties, Utah.         

Understory response to tree harvesting of singleleaf pinyon and Utah juniper

Fifteen widely separated sites within the pinyon - juniper woodlands of the Great Basin were cleared of trees. Understory response was recorded for 2 to 4 years. The array of postharvest plant assemblages were classified into one of four phytosociological groups using discriminant analysis. Pre - and postharvest plant assemblages from the same site appeared in the same phytosociological group, which indicates postharvest response could be predicted from the preharvest plant assemblage. Initial postharvest response appears cyclic in nature, and cycles are controlled by both residual plants and the rapid immigration of shrub species. Perennial plant density generally declined following tree harvest, but the fewer remaining plants produced significantly more cover than in preharvest stands.         

Two new varieties of Eriogonum (Polygonaceae) from the intermountain region

The types and type specimens of Nevada species and varieties of Eriogonum  (Polygonaceae) are alphabetically listed. Appropriate lectotypes are selected as necessary.         

Types of Nevada buckwheats ( Eriogonum: Polygonaceae)

The types and type specimens of Nevada species and varieties of Eriogonum  (Polygonaceae) are alphabetically listed. Appropriate lectotypes are selected as necessary.         

Presettlement vegetation of part of northwestern Moffat County, Colorado, described from remnants

A general botanical inventory of a part of northwestern Moffat County, Colorado, resulted in the location of “ remnants ” of the presettlement vegetation spectrum that are largely unaltered by grazing, logging, or other recent human - related land uses. The 69 samples taken from these remnants were classified into 22 plant associations. Composition, structure, environmental location, geographical range, and response to disturbance are discussed for each association, and a photograph of each is presented. Seven of the 22 associations are apparently restricted to the study area. Restricted associations occur in the more extreme environments of the study area, such as on calcareous substrata or very xeric sites. More mesic sites along ephemeral creeks, on north - facing slopes, or on sandstones support plant associations that have much wider ranges, many of them extending across the northern Great Basin.        

Revision of the Phlox austromontana (Polemoniaceae) complex in Utah

The taxa centering around Phlox austromontana Coville are revised. Named as a new variety is P. austromontana var. lutescens Welsh from eastern Garfield County, Utah. A new combination is provided as P. austromontana var.  jonesii (Wherry) Welsh.