The general bioloy of Cardiaspina albitextura (Psyllidae) and its abundance in relation to weather and Parasitism.

1962 ◽  
Vol 10 (4) ◽  
pp. 537 ◽  
Author(s):  
LR Clark

Cardiaspina albitextura Taylor is a test-forming psyllid which inhabits the foliage of redgums, particularly Eucalyptus blakelyi Maiden, in inland southeastern Australia. In warmer areas, as on the South-West Slopes of New South Wales, this psyllid usually completes three generations per year, whereas in the cooler Southern Tablelands region it normally takes about 18 months to do so. It is a small insect with limited powers of dispersal. The majority of females oviposit within 100 yd of where they originated. The average number of eggs laid per female varies greatly even when individuals are not crowded, the observed range being 14-289. The reproductive rate appears to be influenced by weather conditions, especially by temperature. A few individuals of E. blakelyi are unfavourable to the psyllid and therefore resistant to attack. The susceptible majority exhibit considerable differences and variability in favourableness. In general, however, although there may be marked differences between individuals within stands, average favourableness does not differ greatly from place to place. When the numbers of C. albitextura become very high, i.e. when outbreaks occur, susceptible E. blakelyi suffer severe foliage damage. Where high psyllid numbers occur repeatedly at intervals of less than 3 years, they cause increasing "die back" and host plants produce progressively less new foliage. If outbreaks continue for years, trees are destroyed at an increasing rate. For the 15-20 years prior to 1950 it appears that localized outbreaks of C. albitextura were not uncommon, particularly on the Tablelands, but did not persist for long. Since then extensive outbreaks have occurred in both the Tablelands and Slopes regions. Some have persisted for 10 years and show no signs of ending. Others have lasted only for several psyllid generations. They have been more numerous and persistent in cooler areas than in the Slopes region.

2018 ◽  
Vol 58 (8) ◽  
pp. 1470
Author(s):  
J. S. Richards ◽  
M. A. Sladek ◽  
G. J. Lee

Reproduction is an important driver of profitability in commercial sheep flocks. Historically, Merino flocks have been run with a fixed age structure, ignoring individual merit and casting for age at a specific age. More recently, research has focussed on utilising the variation within age groups by keeping productive older ewes longer and culling less productive ewes earlier. Previous studies have also examined the effect of age on reproduction and the impact of reproduction status on productivity, but little research has been conducted on cumulative effects of reproductive performance on later productivity, reproduction and health. The present study examined the impact of higher lifetime reproduction on other key production and fitness traits in older ewes run under commercial conditions. Data were collected from two commercial wool-producing properties in the South West Slopes and the Central West Plains of New South Wales during 2009–2011. Reproduction, fleece measurements, bodyweight and condition and dental health were recorded during the study. The results showed that age had a bigger effect on productivity and dental health than did cumulative lifetime reproduction. Environment and genetics determined the level of impact, with minimal loss in productivity from increased age of animals occurring in the South West Slopes flock, whereas the Central West Plains flock would appear to require closer monitoring of productivity as ewes aged. The data collected did not allow separation of the genetic and environmental influences within the study. Retaining animals with a higher reproductive performance past normal culling age does not necessarily result in reduction of productivity or ewe health, but this must be monitored.


1999 ◽  
Vol 26 (5) ◽  
pp. 675 ◽  
Author(s):  
P. B. Whitaker ◽  
R. Shine

Encounters between humans and dangerously venomous snakes put both participants at serious risk, so the determinants of such encounters warrant attention. Pseudonaja textilis is a large fast-moving elapid snake responsible for most snakebite fatalities in Australia. As part of a broad ecological study of this species in agricultural land near Leeton, New South Wales, we set out to identify factors influencing the probability that a human walking in farmland would come into close proximity to a brownsnake. Over a three-year period, we walked regular transects to quantify the number and rate of snake encounters, and the proportion of snakes above ground that could be seen. The rate of encounters depended upon a series of factors, including season, time of day, habitat type, weather conditions (wind and air temperature) and shade (light v. dark) of the observers’ clothing. Interactions between factors were also important: for example, the effect of air temperature on encounter probability differed with season and snake gender, and the effect of the observers’ shade of clothing differed with cloud cover. Remarkably, even a highly-experienced observer actually saw <25% of the telemetrically monitored snakes that were known to be active (i.e. above ground) nearby. This result reflects the snakes’ ability to evade people and to escape detection, even in the flat and sparsely vegetated study area. The proportion of snakes that were visible was influenced by the same kinds of factors as described above. Most of the factors biasing encounter rates are readily interpretable from information on other facets of the species’ ecology, and knowledge of these factors may facilitate safer coexistence between snakes and people.


Zootaxa ◽  
2021 ◽  
Vol 5024 (1) ◽  
pp. 1-63
Author(s):  
JORGE RODRÍGUEZ ◽  
PAT A. HUTCHINGS ◽  
JANE E. WILLIAMSON

Flatworms of the Order Polycladida are a group of free-living invertebrates found in a diversity of marine habitats, with over 800 species described worldwide. Marine flatworms are a conspicuous component of Australia’s marine fauna yet have received little attention. Less than 30 scientific articles have been published on Australian marine flatworms since 1855, of which only nine include species from southeastern Australia. Here, the biodiversity and distribution of species belonging to the Order Polycladida inhabiting intertidal rocky beaches in southeastern Australian waters were identified and analysed. Sampling was conducted at low tide along the coasts of New South Wales and Victoria. Collected samples were serially sectioned for comparative anatomical studies, and tissue was removed from each individual for molecular sequencing and analyses. Both nuclear and mitochondrial DNA sequences were obtained and used as an additional source of evidence for the description of new species as well as providing further insight into the phylogenetic relationships between them. A total of 20 species, six of which are new (e.g., Eulatocestus australis sp. nov.), and a new genus (Parabolia gen. nov.) have been described, as well as two new records for Australia (e.g., Stylochoplana clara Kato, 1937) have been identified increasing our knowledge of this important component of the Australian marine biota.  


Author(s):  
Tess S. Bartlett ◽  
Christopher J. Trotter

This article draws from data gathered for an Australian Research Council–funded study conducted in Victoria and New South Wales between 2011 and 2015, which examined how dependent children are responded to when their primary carer is imprisoned. In particular, this article specifically addresses a gap in knowledge by examining the current state of fathering programs in prison in Victoria. To do so, the views of 39 primary carer fathers incarcerated in Victoria are analysed. We argue that there is a distinct lack of support for fathers in prison, acting as a barrier towards maintaining father–child relationships. Findings indicate that 79% of the fathers in this study were never offered any parenting support services or programs. By clearly highlighting the state of fathering programs in prisons in Victoria, this article offers suggestions as to how best to facilitate the connection between incarcerated fathers and their children.


2017 ◽  
Vol 86 (1) ◽  
pp. 51-95 ◽  
Author(s):  
Isabel T. Hyman ◽  
Irantzu de la Iglesia Lamborena ◽  
Frank Köhler

The south-eastern Australian helicarionid clade currently comprises six genera of snails and semislugs united by genital characters, including an epiphallic flagellum that produces a spiraling, spinose spermatophore, the absence of an epiphallic caecum, and the presence of at most a very short vagina. We comprehensively revise the taxonomy of this group based on comparative analyses of key morphological features and mitochondrial markers COI and 16S, revise the placement of several species described recently on the basis of shell morphology alone, and describe new taxa. The snail genus Brevisentis is monophyletic as currently understood, but includes an additional undescribed species from Wollemi National Park, New South Wales. Mysticarion is shown to contain four arboreal semislugs with wide, disjunct ranges, including one new species (Mysticarion obscurior sp. nov.). We synonymise Fastosarion staffordorum with Mysticarion hyalinus. The semislug Desidarion is synonymised with Parmavitrina, and we describe two new species of this genus, P. flavocarinata sp. nov. and P. maculosa sp. nov. The semi-arboreal semislug Cucullarion is herein included in the south-eastern Australian helicarionid clade based on morphological and genetic evidence, despite its more northerly distribution. Two small semislugs so far placed in Peloparion do not group together and a new genus, Ubiquitarion gen. nov., is described for Peloparion iridis. All of these genera, together with the semislug Helicarion (not included here), form a monophyletic radiation endemic to southeastern Australia.


1996 ◽  
Vol 47 (4) ◽  
pp. 643 ◽  
Author(s):  
LC Bowling ◽  
PD Baker

The occurrence of a severe cyanobacterial bloom is described. This bloom affected almost 1000 km of the Barwon-Darling River, New South Wales, Australia, in November and December 1991 and was dominated by Anabaena circinalis Rabenhorst. This cyanobacterium was present in concentrations of around half a million cells per millilitre at some localities during its peak in mid November. Moderate to very high toxicity was demonstrated by mouse bioassay at many localities during this time. The bloom was attributed to very low flow conditions and high nutrient concentrations, especially of total phosphorus. However, warm water temperatures, elevated pH, reduced turbidity, and improved water transparency would also have been contributing factors. Very high ammonia concentrations were also observed during the bloom. The bloom declined during December and was eventually flushed from the river by increased flows following heavy catchment rainfall between mid December and early January.


2002 ◽  
Vol 50 (1) ◽  
pp. 77 ◽  
Author(s):  
M. S. Crowther

Previous work on bioclimatic mapping of species within the Antechinus stuartii–A. flavipes complex has been carried out, but this was before A. subtropicus was recognised and a complete taxonomic revision of the complex had been completed. This revised study of bioclimatic modelling of species within the A. stuartii–A. flavipes complex indicates substantial differences between the four species (A. stuartii, A. agilis, A. subtropicus and A. flavipes) in 35 climatic indices. A. stuartii is predicted to have a near-coastal distribution in northern and central New South Wales stretching as far south as Kioloa and as far north as south-eastern Queensland, avoiding the far coastal strip. A. agilis is predicted to have an extensive distribution in Victoria and southern New South Wales as far north as western Sydney; it is also predicted to occur in Tasmania, even though there is no evidence of it ever occurring there. A. flavipes is predicted to have an extensive inland and coastal distribution much larger than its recorded distribution. A. subtropicus is predicted to have a very narrow distribution in areas with high seasonal rainfall and high temperatures with low seasonality. All species are predicted to occur sympatrically, with A. stuartii and A. agilis predicted to have extensive overlap on the coast near Kioloa and to the immediate west and south-west of Sydney.


2002 ◽  
Vol 14 (4) ◽  
pp. 431 ◽  
Author(s):  
J. C. Noble ◽  
G. H. Pfitzner

William Rodier (1859–1936) became well known throughout much of southeastern Australia during the late nineteenth and early twentieth centuries, mainly through the vigour with which he expressed his contentious views on how best to control certain vertebrate pests. Much of his 'plan', particularly in regard to rabbits, was based on his experience as a pastoralist in western New South Wales. In this article, we examine what is known about Rodier's family background, his occupations, preoccupations, and particularly, the effectiveness of his endeavours to convince a largely sceptical public as to the wisdom and practicality of his method for vertebrate pest control. Some of the circulars and flyers printed by Rodier are also reproduced for illustrative purposes. These were designed to demonstrate the effectiveness of the Rodier Method, especially for controlling the rabbit, perceived by him to be the most serious threat then facing landholders in Australia. Rodier's activities are appraised in light of the relationship then existing between community-based science and more orthodox, academically-based science in the late nineteenth and early twentieth century. Finally, this relationship is further explored in an historical context by examining the importance attached to local, informal knowledge in contemporary ecological research where landholder collaboration is now often regarded as an integral component.


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