SHORT-TERM IMPACTS OF FORMULATIONS OF BACILLUS THURINGIENSIS VAR. ISRAELENSIS DE BARJAC AND THE ORGANOPHOSPHATE TEMEPHOS,USED IN BLACKFLY (DIPTERA: SIMULIIDAE) CONTROL,ON RHEOPHILIC BENTHIC MACROINVERTEBRATES IN THE MIDDLE ORANGE RIVER,SOUTH AFRICA

Summary

The impacts of larvicides used in the control of blackflies (Diptera: Simuliidae) on macroinvertebrates in the stones-in-current biotope were assessed during 8 field trials in the middle Orange River, South Africa. Two Bacillus thuringiensis var. israelensis (B.t.i.) products (Vectobac^R 12AS and Teknar^R HP-D) and the organophosphate temephos (Abate^R 200EC) were applied at recommended and high dosages to simulate “operational” and “worst-possible” scenario's respectively. Mortality was evaluated either by direct counting of invertebrates on stones before and after application, or by ranking invertebrates on a 4-point relative abundance scale before and after application. In addition, the re-appearance of benthic invertebrate population densities after temephos application was examined.

At the recommended dosage (1.2 ppm/10 min), B.t.i. significantly reduced blackfly larval numbers (P<0.001) and those of the chironomid Rheotanytarsus fuscus Freeman (P<0.05). At high dosage (20 ppm/10 min), numbers of the filter-feeding mayfly Tricorythus discolor (Burmeister) (P<0.01) and the chironomid Cardiocladius sp. (P<0.05) were also significantly reduced. No Simulium predators were directly affected by B.t.i., but there were indications of food shortage amongst Hydropsychidae and Hirudinea.

Temephos caused significant reductions in the relative abundance of 5 taxa at 0.05 ppm, 3 to 6 taxa at 0.1 ppm, and 9 taxa at 1.0 ppm (P<0.05). “Non-target” organisms which were most affected included the chironomid R. fuscus, the mayflies Baetis glaucus Agnew and Choroterpes elegans Barnard, and the caddisflies Cheumatopsyche thomasseti Ulmer and Amphipsyche scottae Kimmins. The mayfly T. discolor was tolerant of temephos, even at high dosage (1.0 ppm/10 min). In winter, most taxa re-appeared within 19 days, and population densities were back to pre-treatment levels within 35 days.

It is concluded that good reduction of blackfly populations may be obtained with minimal direct impact on the “non-target” fauna, provided recommended dosages of temephos are not exceeded. Overdosing with temephos may result in high mortality of “non-target” organisms, including blackfly predators, and should be avoided.     

Halocnemum M. Bieb. vegetation in the Mediterranean Basin

The aim of the article is the syntaxonomic interpretation of hyperhalophilous woody or semi-woody vegetation with Halocnemum M. Bieb. along the coasts of the Mediterranean Basin. For this area, the two species of Halocnemum, H. strobilaceum (Pall.) M. Bieb. and H. cruciatum (Forssk.) Tod. are identified; their morphological characteristics, synonymy and distribution are here described. The study carried out of particular aspects of the plant morphology and the micromorphological characteristics of the seeds collected from different places in the Mediterranean allows to better differentiate the two species. Vegetation studies already done in many communities of the Mediterranean by several authors threw into great confusion because only H. strobilacem has been recognized as a dominant species. As regards the syntaxonomic analyses of the vegetation, the authors refer to the proposals already made by various scientists for the vegetation of inland salt basins of Eurasia and the Irano-Anatolian area, who suggested the classes Kalidietea foliate and Halocnemetea strobilaceiirano-anatolica, respectively. Conversely, in the Mediterranean Basin, the vegetation study is present only in coastal areas where it is considerably impoverished in the number of species. Therefore, the authors propose to include hyperhalophilous, woody and fruticose vegetation in the class Sarcocornietea fruticosae. However, the phytosociological and ecological diversity is highlighted proposing the order Halocnemetalia cruciati in which both the alliance Halocnemion strobilacei, for middle Eastern Europe, and the alliance Halocnemion cruciati, for North Africa with penetrations in the Western and Eastern Europe up to the Middle East coast, are included. This new interpretation has required the correction of the names of two associations (Frankenio corymbosae–Halocnemetum cruciati and Zygophylloalbi–Halocnemetumcruciati) and the proposal of two new associations Arthrocnemo machrostachyi–Halocnemetum cruciati and Halocnemo cruciati–Sarcocornietum fruticosae. A further proposal concerns the addition of the alliance Limoniastrion monopetali, previously included in the order Limonietalia, in the order Halocnemetalia cruciati.     

Possible noncalcareous algae in the upper part of the bell canyon formation (Permian), New Mexico

A new genus and species of alga called Sinoglypha nassichuki is identified and described from Guadalupian rocks of the Delaware Basin, New Mexico. It occurs in tilted to almost upright position in laminites generally accepted as being deposited in deep, anoxic water. The fossils are noncalcareous, having a wavy nature. They are not classed as trace fossils of animals. They are leafy, 2–5 cm long and may be preserved in original position.

If Sinoglypha is an alga it leads to the tentative, but not new, conclusion that perhaps the water was not deep but shallow enough for light penetration—30 meters for the upper part of the Bell Canyon Formation.     

New Data on Therangospodus oncalensis from the Berriasian Fuentesalvo Tracksite (Villar del Río,Soria, Spain): An Example of Gregarious Behaviour in Theropod Dinosaurs

Therangospodus oncalensis is a Berriasian theropod ichnotaxon from the Cameros Basin (Soria Province, Spain). We discovered new trackways assigned to this ichnotaxon during cleaning and conservation works at the type locality (Fuentesalvo), enabling us to describe it more precisely. Therangospodus oncalensis was made by a medium-sized theropod dinosaur and is characterized by a single tapering pad on each toe, a rounded heel impression and a narrow trackway. In addition to having similar morphometric characteristics, most of the trackways at the Fuentesalvo site show comparable size and biometric features. This indicates that, in terms of size and age, a homogeneous population of a single theropod species could have produced these tracks. Moreover, the similar orientation (lying within a range of only 15°) and estimated speed suggested by most of the trackways, lend weight to the hypothesis that the trackmaker of Therangospodus oncalensis was able, at least at times, to move in structured packs displaying gregarious behaviour. Furthermore, this is the first structured pack of theropods to be described.     

Linkichnus Terebrans New Ichnogenus et Ichnospecies,an Insect Boring from the Late Triassic of the Germanic Basin,Southern Germany

The proposed new ichnotaxon Linckichnus terebrans n. ig. et isp., is a small test-tube shaped boring produced by insects in a sphenophyte stem and occurs in Upper Triassic (Keuper) terrestrial deposits.     

Bivalve Wood Borings of the Ichnogenus Teredolites Leymerie from the Bohemian Cretaceous Basin (Upper Cretaceous,Czech Republic)

Finds of fossil wood with bivalve wood borings (Teredolites clavatus and T. longissimus) occur in various facies and presumed sedimentary settings of the platform, shallow-marine Bohemian Crectaceous Basin. The basin comprises areas with sandy-dominated sediments, with marl and clay-dominated sediments, areas with predominat sandy-marly rocks, and finally areas dominated by calcareous nearshore sediments. Teredolites clavatus is common in fossil wood of sandstones, originating in beach or deltaic settings; marl and clay-dominated rock frequently bear wood fragments densely bored by Teredolites longissimus. When accompanied by evidence of marine environments as body fossils, glauconite or typical trace fossils, most of the wood fragments are bored. The presence/absence of borings in wood fragments can be considered the most reliable and easily useable criterion of distinction of marine settings in sandy sediments of the margin of the Bohemian Cretaceous Basin.     

Ecosystem Services from Keystone Species: Diversionary Seeding and Seed‐Caching Desert Rodents Can Enhance Indian Ricegrass Seedling Establishment

Seeds of Indian ricegrass (Achnatherum hymenoides), a native bunchgrass common to sandy soils on arid western rangelands, are naturally dispersed by seed‐caching rodent species, particularly Dipodomys spp. (kangaroo rats). These animals cache large quantities of seeds when mature seeds are available on or beneath plants and recover most of their caches for consumption during the remainder of the year. Unrecovered seeds in caches account for the vast majority of Indian ricegrass seedling recruitment. We applied three different densities of white millet (Panicum miliaceum) seeds as “diversionary foods” to plots at three Great Basin study sites in an attempt to reduce rodents' over‐winter cache recovery so that more Indian ricegrass seeds would remain in soil seedbanks and potentially establish new seedlings. One year after diversionary seed application, a moderate level of Indian ricegrass seedling recruitment occurred at two of our study sites in western Nevada, although there was no recruitment at the third site in eastern California. At both Nevada sites, the number of Indian ricegrass seedlings sampled along transects was significantly greater on all plots treated with diversionary seeds than on non‐seeded control plots. However, the density of diversionary seeds applied to plots had a marginally non‐significant effect on seedling recruitment, and it was not correlated with recruitment patterns among plots. Results suggest that application of a diversionary seed type that is preferred by seed‐caching rodents provides a promising passive restoration strategy for target plant species that are dispersed by these rodents.     

Effects of flooding on recruitment and abundance of Golden Perch (Macquaria ambigua ambigua) in the lower River Murray

Flooding is often considered a stimulus for production of fish in floodplain rivers. In the southern Murray–Darling Basin (MDB), Australia, however, few native fish species have been shown to use the floodplain for spawning, and recruitment has been positively and negatively associated with flooding. In 2010/11, extensive flooding in the lower River Murray provided an opportunity to investigate the recruitment response of Golden Perch (Macquaria ambigua ambigua) following 10 years of drought and floodplain isolation. Annual variation in Golden Perch abundance and recruitment were investigated in anabranch and main channel habitats at Chowilla in the floodplain geomorphic region of the lower River Murray over a 7‐year period incorporating the flood and 6 years of in‐channel flow. Spatial variation in recruitment in the lower River Murray was also investigated by comparing the age structure of Golden Perch in the swamplands/lakes, gorge and floodplain geomorphic regions. Golden Perch abundance in the Chowilla region increased significantly postflooding compared with drought years. Age structures indicated that increased abundance was due predominantly to fish spawned during the flood (2010/11) and the previous year (2009/10), which was characterised by in‐channel flows. Age structure was similar in the nearby Katarapko Anabranch system indicating a uniform postflood recruitment response in the floodplain geomorphic region. Juvenile Golden Perch from the 2010/11 and 2009/10 cohorts were less apparent in the gorge and swamplands/lakes regions. Golden Perch have flexible life histories and will spawn and recruit in association with in‐channel rises in flow and overbank flows, but significant increases in abundance in the lower River Murray may result from overbank flooding. Contemporary approaches to flow restoration in the MDB emphasise overbank flows and floodplain processes. We suggest, however, that environmental flow management that incorporates floodplain and in‐channel processes, at appropriate spatio‐temporal scales, will result in more robust populations of Golden Perch.     

Ecological monitoring to support Water Sharing Plan evaluation and protect wetlands of inland New South Wales,Australia

Government‐funded flow response monitoring and modelling programmes (flow science) provided by the New South Wales Office of Water (NOW) have supported water resource management since 1997. Flow science has a core technical component defined by hypothesis‐driven long‐term monitoring and analysis, but it also represents many activities that support committees involved in environmental flow management. This is done through collaborations and contracting and has fostered considerable research and analysis into flow ecology, including modelling for the recent Murray–Darling Basin Plan. We describe the performance of environmental flows against legislated wetland objectives to improve wetland function and diversity using flow science. On‐ground monitoring at wetland sites has largely ceased but the flow science done so far indicates that the environmental flow rules written into Water Sharing Plans improve wetland diversity and function. Determination of the long‐term flow needs of NSW wetlands, including how well current Water Sharing Plans aid the delivery of environmental flows, requires finding the means to build on current flow science knowledge from across Australia.