Variation in germination response to temperature and water availability in blackbrush ( Coleogyne ramosissima ) and its ecological significance

Blackbursh ( Coleogyne ramosissima Torr.) is a dominant desert shrub in a distinct mid-elevations vegetation belt between creosote bush-bursage ( Larrea tridentata-Ambrosia dumosa ) shrubland below and big sagebrush-pinyon pine- Utah juniper ( Artemisia tridentata-Pinus monophylla-Juniperus osteosperma ) woodland above in the Mojave Desert. Seed germination patterns of blackbrush seeds collected from 2 elevations (1200 and 1550 m) in 5 mountain ranges within the blackbrush shrublands were investigated. Morphological features of blackbrush seeds, including weight, length, and width, were not significantly different ( P > 0.05) among elevations and mountain ranges in the Mojave Desert. Germination of blackbrush seeds was optimal when preceded by a prechill period of 4-6 wk. Seeds incubated at room temperature germinated poorly. Seeds collected at warm, low-elevation sites appeared to be less dormant (required less prechill time), germinated faster, and showed a higher overall germination response; watering at 2-wk intervals revealed the greatest germination. Some ecotypic variation among populations establishing at different elevations was evident with regard to dormancy duration and germination response at certain constant temperatures.     

Environmental attributes correlating with density of blackbrush ( Coleogyne ramosissima ) shurbs in the Spring Mountains of southern Nevada

Discovery of distinct mid-elevational bands of blackbrush ( Coleogyne ramosissima Torr.) shrublands on desert mountain slopes in the Mojave Desert caused an investigation of the relationships between environmental factors and Coleogyne distribution. Environmental factors were quantitatively examined to determine which were significant predictors of Coleogyne density at upper-elevational limits (ecotones) in the Spring Mountains of southern Nevada. Path analysis revealed significant, direct causal effects of air temperature, soil moisture, soil depth, and percent litter cover on the distribution of Coleogyne . Specifically, air temperature was a significant positive predictor, while soil moisture, soil depth, and percent litter cover were significant negative predictors of Coleogyne density, with the effects of other environmental variables parceled out. Path analysis also indicated that indirect effects of soil pH, bulk density, compaction, percent pore space, organic matter, soil temperature, salinity, cryptogam, and percent bare soil and rock cover on Coleogyne density were substantially more potent than their direct casual effects. Environmental attributes associated with elevational changes correlate with and may determine the density of Coleogyne shrubs at upper ecotones in southern Nevada.     

Plant community patterns in unburned and burned blackbrush ( Coleogne ramosissima Torr.) shrublands in the Mojave Desert

The blackbrush vegetation type is dominated by Coleogyne ramossisima , which is thought to preclude the coexistence of many other plant species. Fire can remove blackbrush cover and possibly increase plant species richness and evenness. Fire also may increase the frequency and cover of alien annual grasses, thereby intensifying landscape flammability. We tested these predictions in unburned and burned (6-14 years postfire) blackbrush at 3 sites spanning the range of this vegetation type in the Mojave Desert. Species richness in unburned blackbrush was similar to published values for vegetation types in western North America, bur richness varied significantly among the 3 sites and 4 spatial scales (1, 10, 100, and 1000 m 2 ). Richness values declined in order from annual forbs, woody perennials, herbaceous perennials, annual grasses, cacti, to perennial grasses. Fire reduced Coleogyne cover, thus boosting species evenness. In contrast, species richness decreased after burning, although the results varied among spatial scales. Total cover was unaffected by fire because cover of wood perennials decreased, while cover of annual forbs, annual grasses, herbaceous perennials, and perennial grasses increased. Native species richness and cover decreased, whereas alien richness and cover increased after burning especially where the alien forb Erodium cicutarium was present. Fire had no effect on frequency and variable effects on cover of alien annual grasses. These results indicate that in blackbrush species richness can vary among sites and local spatial scales, and effects of fires can vary among plant life-forms and between natives and aliens.     

Effects of salinity on establishment of Populus fremontii (cottonwood) and Tamarix ramosissima (saltcedar) in southwestern United States

The exotic shrub Tamarix ramosissima (saltcedar) has replaced the native Populus fremontii (cottonwood) along many streams in southwestern United States. We used a controlled outdoor experiment to examine the influence of river salinity on germination and first year survival of P. fremontii var. wislizenii (Rio Grande cottonwood) and T. ramosissima on freshly deposited alluvial bars. We grew both species from seed in planters of sand subjected to a declining water table and solutions containing 0, 1, 3, and 5 times the concentrations of major ions in the Rio Grande at San Marcia, NM (1.2, 10.0, 25.7 and 37.4 meq 1 -1 ; 0.11, 0.97, 2.37, and 3.45 dS m -1 ). Germination of P. fremontii declined by 35% with increasing salinity ( P = .008). Germination of T. ramosissima was not affected. There were no significant effects of salinity on morality or above- and belowground growth of either species. In laboratory tests the same salinities had no effect on P. fremontii germination. P. fremontii germination is more sensitive to salinity outdoors than in covered petri dishes, probably because water scarcity resulting from eavaportion intensifies the low soil water potential associated with high salinity. River salinity appears to play only a minor role in determining relative numbers of P. fremontii and T. ramosissima seedlings on freshly deposited sandbars. However, over many years salt becomes concentrated on floodplains as a result of evaporation and salt extrusion from saltcedar leaves. T. ramosissima is known to be more tolerant of the resulting extreme salinities than P. fremontii . Therefore, increases in river salinities could indirectly contribute to decline of P. fremontii forests by exacerbating salt accumulation on floodplains.     

Identification of Megaselia scalaris (Loew, 1866) (Diptera: Phoridae) in mummified human body from Itacambira (MG), Brazil,using scanning electron microscopy and cuticular hydrocarbons

Insect puparia were found adhered to the ribs and other tissues in the abdominal cavity of a natural male mummy found in Itacambira (State of Minas Gerais, Brazil) dating to the Colonial Period. They were collected for identification by scanning electron microscopy, and for comparison of several morphological features with those described in the literature. The puparia were found open and dorsoventrally flattened, making it difficult to visualize the dorsal projections. The tegument is covered by tapered spines and contains rows of small tubercles on the dorsal and lateral regions of the puparium. The posterior spiracle consists of four parallel openings arranged in pairs. These results are indicative that the specimens belong to the species Megaselia scalaris (Loew, 1866) (Diptera: Phoridae). Additionally, cuticular hydrocarbons of the puparia were analysed by gas chromatography coupled to mass spectrometry and compared with the profile of M. scalaris reared in the laboratory.     

Aspects of natural history in a sand boa,Eryx muelleri (Erycidae) from arid savannahs in Burkina Faso,Togo, and Nigeria (West Africa)

The ecology of West African arid savannah snakes is still poorly known, especially in regard to the fossorial species. Here, field data on distribution, morphometrics, habitat use and diet are reported for the sand boa Eryx muelleri (Erycidae) from three different countries, i.e. Burkina Faso, Togo and Nigeria. This snake was observed in 21 distinct localities, and a total of 39 individuals was recorded. The species is likely fairly common and locally abundant. Mean body length of snakes was similar among countries and between sexes, but males had proportionately longer tails than females. Body length was significantly positively correlated with both tail length and head length. Adult sex ratio was close to parity. Most of the specimens were found in well-vegetated spots with low percentage of bare soil. There were apparently both ontogenetic and intersexual dietary variations: (1) a single analysed juvenile fed upon a small-sized lizard, whereas adults fed considerably upon young rodents; and (2) females fed exclusively upon young rodents and males upon both lizards and young rodents. In conservation terms, the species is actively exported from Togo for the pet trade, and additional individuals may also be illegally collected in other countries.     

Hispid cotton rat ( Sigmodon hispidus ) in Nebraska: distribution, reproduction, and seasonal activity

The hispid cotton rat ( Sigmodon hispidus ) has occurred in Nebraska for about 50 years and entered the state from the south via northward movements through Kansas. However, little is known about its status or distribution in the state in recent decades. We conducted surveys for S. hispidus in southern Nebraska at historical sites and sites without previous records to determine its current status. From 2004 to 2008, we documented cotton rats at 9 of 12 historical sites in south-central and extreme southeastern parts of the state, and we captured this species at 13 new sites in southwestern and south-central Nebraska. In the past 3 decades, the distribution of S. hispidus has expanded westward but not northward in the state. An explanation for such a shift is unclear. At this northern edge of its geographical range, pregnant females were captured from early April to early October, and nonreproductive females were captured from November to January. Males with enlarged testes occurred from late March to September. Aspects of its natural history in Nebraska are similar to those reported in Kansas.     

Lanayrella,a new Acteonidae genus (Gastropoda,Heterobranchia) from Tierra del Fuego

ABSTRACT

We introduce herein Lanayrella gen. nov. to accommodate two Acteonidae species that have proven resistant to stable classification: Tornatella vagabunda Mabille, 1885 and Acteon ringei Strebel, 1905. The new genus is diagnosed by a protoconch fully immersed within the shell and a platform-like columellar region of the aperture, which bears a strong and sharp adapical fold. Both species are restricted to Tierra del Fuego: Lanayrella vagabunda comb. nov. on the Chilean part and Lanayrella ringei comb. nov. on the Argentinean side.

http://www.zoobank.org/urn:lsid:zoobank.org:act:37EA6720-0E0E-4C81-A2A8-F85FA2E53929     

A review of red-eye pigmentation and diel activity patterns in skippers (Lepidoptera,Papilionoidea, Hesperiidae)

ABSTRACT

The visual systems and diel activity patterns of butterflies and moths have been studied for decades, yet understanding the underlying mechanisms that are associated with the evolution of these remains a major challenge. The order Lepidoptera is principally composed of nocturnal lineages with extreme morphological and behavioural adaptations to this lifestyle. Although most butterflies are diurnal, some clades are predominantly nocturnal, for instance, the Hedylidae. Skippers are another family that comprises multiple crepuscular and/or nocturnal lineages. Interestingly, many such lineages have red-eye pigmentation, and this morphological feature has been hypothesised to be an adaptation to the night-time lifestyle. Here, we review the occurrence and frequency of red-eye pigmentation as well as diel activity patterns in Hesperiidae. We place these data within a phylogenomic framework and provide hypotheses and predictions relative to the evolution of red-eye pigmentation in skippers with respect to diel activity. We suggest that several types of red-eye pigmentation exist in skippers, with possible structural red-eye pigmentation in some lineages of diurnal skippers. The colouration of eyes in Hesperiidae, the evolutionary mechanisms that drive these traits and the physiological underlying processes require further attention and could bring new insights into our understanding of butterfly vision systems.     

Specimens of a New Zealand terrestrial planarian,Artioposthia exulans (Dendy, 1901) (Platyhelminthes: Geoplanidae) from Cornwall,UK

ABSTRACT

Specimens of a terrestrial planarian found in Cornwall, UK in 2013 and 2016 are of Artioposthia exulans (Dendy, 1901), a species previously recorded only from Chatham Island and North Island, New Zealand.     

Chroestia,a new supralittoral amphipod genus from Queensland,Australia (Talitroidea: Talitridae)

Chroestia lota, a new genus and species of talitrid amphipod from the shores of Moreton Bay, is described and figured. Its relationship to other ‘beach flea’ genera (Protorchestia, Transorchestia, Orchestia) and to the endemic Australian forest-dwelling genus Agilestia are discussed.     

A new species of Protocladorchis (Paramphistomidae,Dadaytrematinae) from Pangasius nasutus (Bleeker, 1863) in Thailand

Protocladorchis chinabutae sp. nov. from Pangasius nasutus in Thailand differs from Protocladorchis burmanicus mainly in the size, shape and position of the testes and from P. pangasii in body shape, egg size and the shape of the pharyngeal sacs. The genus has not previously been reported from Thailand.     

Daily activity of the white-clawed crayfish,Austropotamobius pallipes (Lereboullet): a comparison between field and laboratory studies

The daily activity of the threatened crayfish, Austropotamobius pallipes (Lereboullet), was studied both in the field, through direct counts of active animals along a stream section, and in the laboratory, by means of actographs. In the field, crayfish were mostly found after dawn, with a slight but significant difference among seasons. In winter, only two specimens were seen to be active. Distinguishing among size classes, medium-sized crayfish were more abundant in spring and summer, while large ones mostly occurred in autumn. The former always concentrated their activity at night-time; to the contrary, larger specimens were more active late at night in spring and at dusk in autumn. Sex-ratio, analysed only in summer, was balanced throughout the 24h. Nocturnal activity, although differing among seasons, was similar in size classes, temperatures and sexes. In the laboratory, activity (evaluated as photo-cell interruptions) increased with temperature and occurrence throughout a 24-h cycle (the highest peak shifting from midnight to dusk). Only in the laboratory, a low peak occurred at dawn, but disappeared when a shelter was available. The interaction between the response of A. pallipes to temperature and its nocturnal habit is examined. Questions still remain on the adaptive value of the environmental factors influencing the cycle of freshwater decapods' activity.     

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 .     

On a new genus and species of centipede (Chilopoda,Geophilomorpha, Chilenophilidae) from the British Isles

A new genus and species of geophilomorph centipede, Nothogeophilus turki is described from the Scilly Isles and the Isle of Wight. The precise relationships of this new genus are not clear. The species is, presumably, an introduction.     

A new species of Passalus (Passalus) from Atlantic Rainforest,with a key and checklist for the Brazilian Petrejus group (Coleoptera,Passalidae)

ABSTRACT

A new species of Passalus is described from the Brazilian Atlantic Forest. A synthesis of the current state of knowledge concerning the Brazilian species of the Petrejus group is presented with a new key to the described Passalus lockerum sp. nov., which is characterized by the frontal area finely and sparsely punctate, interstices shiny; anteriorly with distinct rounded, coarse and shallow punctures, contiguous or not. Also, the secondary median frontal tubercles are close, vestigial to small and subcontiguous at base. Unique characteristic specific to the aedeagus are also important. The species is restricted to a protected conservation area of the Atlantic Forest in the state of Rio de Janeiro.

www.zoobank.org/urn:lsid:zoobank.org:pub:A0A6251E-DFD0-4BB7-90EE-D7FA29AE8243