Capnia caryi, an interesting new species of winter stonefly from the American Southwest (Plecoptera: Capniidae)

Capnia caryi , a new species of Nearctic Capniidae, is described from adults collected from high-elevation locations in the Southern Rocky Mountains of southern New Mexico and Arizona. Males are distinguished by their rounded club-shaped epiproct and sclerotized knobs on abdominal terga 8 and 9. Females possess a darkly sclerotized subgenital plate that covers most of tergum 8 and is produced posteriorly as a pair of broadly rounded lobes.     

The generic name of the North American musk turtles

Although several recent workers have used the name Sternothaerus for the North American musk turtles, the rules of priority render Sternotherus the correct name for them. The generic type fixation by Stejneger of S. odoratus is accepted.     

Karyotypes of the long-tailed vole ( Microtus longicaudus ) in isolated mountain ranges of the American Southwest

The long-tailed vole ( Microtus longicaudus ) exhibits karyotypic variation in western North America. In the American Southwest, the species has a disjunct, relict distribution. However, karyotypes obtained from 20 specimens in 5 isolated mountain ranges (White Mountains, Arizona; Mount Taylor and the Sangre de Cristo, Jemez, and Mogollon mountains, New Mexico) exhibited no variation. These and previously reported karyotypes from the region had a diploid number (2n) of 56 and fundamental number (FN) of 84, which is the most commonly reported karyotype for the species.     

Spawning behaviour and sexual dimorphism in the North American cyprinid fish Notropis leedsi,the bannerfin shiner

The spawning behaviour and sexual dimorphism of the little known North American cyprinid fish, Notropis leedsi, is described based on observations made in laboratory aquaria. Notropis leedsi is a crevice spawning species, a trait characteristic of members of the subgenus Cyprinella. Males establish breeding territories through ‘mock battles’ and defend them by chasing away intruding males or, at times, through threat displays or ‘mock battles’. Although wild-caught males are significantly larger than females, sexual dimorphism is more pronounced in the colour pattern and fin size, especially the dorsal and anal fins.

The modes of spawning behaviour in the genus Notropis are reviewed. The relationship between the promiscuous mating system (polybrachygamy), the crevice spawning mode, and sexual dimorphism in N. leedsi are discussed in relation to current notions regarding sexual selection.     

Genetics of allopatric populations of the montane vole ( Microtus montanus ) and Mogollon vole ( Microtus mogollonensis ) in the American Southwest

Variation at 21 allozyme loci and 10 restriction enzymes within the mitochondrial DNA control region was assessed among 3 allopatric populations of montane vole ( Microtus montanus ) in the American Southwest. Among populations of M. montanus , the population from the White Mountains, Arizona, was most genetically divergent. Genetic and biogeographic evidence supported recognition of the White Mountains population as a distinct subspecies, M. m. arizonensis . Results also supported recognition of the Mogollon vole ( Microtus mogollonensis ) as distinct from the Mexican vole ( Microtus mexicanus ).     

The epibionts of beach hoppers (Crustacea: Talitridae) of the North American Pacific coast

The beach hoppers Megalorchestia californiana and M. corniculata (Crustacea: Talitridae) were studied for the interaction of two of their epibionts. Rhabditid nematodes reside under the host's dorsal pereonites where they may be facultative parasites or feed on bacteria and detritus associated with the host. The mite Thinoseius brevisternalis (Canaris, 1962) (Acari: Eviphididae) preys upon the above nematodes. Both nematodes and mites also use the host as transport between patches of beach wrack. Other epibiotic Acari on talitrids are also reported here.     

Multi-scale patterns in the host specificity of plant-dwelling arthropods: the influence of host plant and temporal variation on species richness and assemblage composition of true bugs (Hemiptera)

The influence of temporal variation in the host specificity of invertebrates to estimates of biodiversity is rarely considered. While patterns at large spatial scales have stimulated much attention, such comparisons are constrained for southern-hemisphere biomes because the patterning of invertebrates on plants is largely unknown. Here, we analyse variation of plant-dwelling Hemiptera from 15 understorey plant species over 18 months in the south-west Australian biodiversity hotspot. Analyses showed significant interactions in species composition between sampling period and plant species. Fauna that were “effectively specialized” (host-specificity index) to plants changed with season, although this was also related to the number of singletons and overall species richness. Sampling from a single season also overestimated the degree of host specificity by 52% and underestimated the perception of species richness when an outbreak of a particular herbivore occurred. High host-specificity values (12.7 hemipteran species per plant) support the case for high estimates of global arthropod richness.     

A character analysis of the North American potter wasps (Hymenoptera: Vespidae; Eumeninae)

A cladistic analysis of the nearctic genera of Eumeninae is presented. The ground plan states of 43 character systems are discussed, and the first comprehensive cladogram for any significant portion of the subfamily is presented. At least eight of the 26 genera are apparently nonmonophyletic: Zethus, Montezumia, Euodynerus, Odynerus, Pterocheilus, Stenodynerus, Leptochilus and Microdynerus. A key to the nearctic genera accompanies the text.     

Scanning electron microscopic study of the male genitalia of the North American alderfly genus Sialis (Megaloptera: Sialidae)

Scanning electron micrographs are presented for 14 species of the North American alderfly Sialis : americana , arvalis , californica , contigua , cornuta , hamata , iola , joppa , mohri , nevadensis , occidens , rotunda , vagans , and velata . Male genitalic characters are described for use in species identification.     

Climbing as an escape behavior in the American hog-nosed skunk, Conepatus leuconotus

Climbing behavior is poorly documented in skunk species, with the exception of the genus Spilogale. Herein we describe 2 cases of climbing behavior in the American hog-nosed skunk ( Conepatus leuconotus ): one in Colima, Mexico, and another in west central Texas, USA. In both cases, a male climbed over 5 m into oak trees when pursued by humans. Climbing as an escape behavior in hog-nosed skunks has not previously been reported.     

Pseudocrossidium obtusulum (Pottiaceae, Bryopsida) new to Montana with a key to North American apecies in the genus

The moss species Pseudocrossidium obtusulum (Lindb.) Crum & Anderson is reported for the state of Montana. Recent systematic of the genus Pseudocrossidium in North America is discussed.     

Infection of young Douglas-firs by dwarf mistletoe in the Southwest

Studies in several areas in Arizona and New Mexico show that dwarf mistletoe ( Arceuthobium douglasii ) is rare in young Douglas-firs growing under infected overstories. Less than 5% of the Douglas-firs under 26 years old and less than 6% of those under 1.4m tall were infected in 77 mistletoe-infested stands. Both percent infection and mean dwarf mistletoe rating of young Douglas-firs increased as tree age, height, and stand dwarf mistletoe ratings increased.     

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.         

Stridulation in Aphodius dung beetles: Songs and morphology of stridulatory organs in North American Aphodius species (Scarabaeidae)

The acoustic behaviour of four Aphodius dung beetle species from the Pacific Northwest of the USA was investigated. Male Aphodius produce substrate vibrations when they meet a conspecific female in a dung pat. The temporal structure of the substrate vibrations and the stridulatory organs are described. The vibrations are species-specific songs that are emitted during courtship. The stridulatory organ is of the abdomino-alary type in the investigated species. Morphological differences with regard to the detailed structure are present.     

Geographic variability in the genetic polymorphism of the Isopod,Venezillo evergladensis

Influence of host on hook morphology, soluble protein profile and two polymorphic loci of the marine tapeworms, Hepatoxylon trichiuri and H. megacephalum were studied. It was found that hook lengths of the two parasites differed significantly and that they varied with the host species. Unweighted pair-group analysis of soluble protein similarity indices separated H. trichiuri and H. megacephalum into three groups by fish host species. Allozyme analyses revealed that a polymorphic locus, glucose-6-phosphate dehydrogenase, of H. trichiuri showed significant variations in the allelic and phenotypic frequencies between populations of parasites from different host species, but a second polymorphic locus, esterase, did not show any host-related variation. Owing to the small sample size of H. megacephalum statistical analysis was not carried out for the allozyme study. However, allelic frequencies of the Est locus differed significantly between the two parasites. The possible influence of fish hosts on parasite morphology, protein biochemistry and population genetics was discussed.     

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.         

Infection of young Douglas-firs and spruces by dwarf mistletoes in the Southwest

Mistletoe infection of Douglas-fir and spruce seedlings increased as the mean dwarf mistletoe rating of the overstory, seedling density, and total age of seedlings increased. Percent of spruce seedlings infected increased more rapidly than for Douglas-fir as overstory dwarf mistletoe ratings increased. However, the intensity of infection as measured by the mean dwarf mistletoe rating of seedlings, increased at about the same rate for spruce and Douglas-fir. Percent infection of seedlings less than 20 years total age was higher for spruce than for Douglas-fir. Douglas-fir and spruce seedling mortality was from two to three times greater in heavily infested stands than in healthy stands.