NOTES ON SOME GRASSES. XVI. EMBRYO STRUCTURE OF THE GENUS ORYZA IN RELATION TO THE SYSTEMATICS

Three distinct types of embryo have been found in 18 species of the genus Oryza. Type 1 is characterized by lateral fusion of the epiblast and the scutellum and also by the development of auricles. Type 2 has no auricle, and the epiblast is not laterally fused with the scutellum. Type 3 has a cleft between the lower part of the scutellum and the coleorhiza, a long epiblast which is free from the scutellum, and lacks auricles. Type 1 has been found in 13 species of section Sativae, Type 2 in 4 species of sections Granulatae and Coarctatae, and Type 3 in O. coarctata only. The results indicate that species of section Sativae are more or less closely related, while section Coarctatae is a heterogeneous group. A new section, Ridleyianae, has been described for Oryza ridleyi and some other species. Oryza coarctata has unique features in embryo structure, morphology and leaf anatomy, and this species has been moved from the genus Oryza to a separate genus, Sclerophyllum, which is here revived.     

A new species of spider mite, Oligonychus palus sp. nov. (Prostigmata: Tetranychidae), from tropical Australia

Abstract  A new spider mite, Oligonychus palus sp. nov . , is described from banana in northern Australia. Comments are made about the validity of the subgenera within Oligonychus Berlese and the new species is compared with a similar Indian species O. sapienticolus Gupta.     

Chloroplast genome sequence confirms distinctness of Australian and Asian wild rice

Cultivated rice (Oryza sativa) is an AA genome Oryza species that was most likely domesticated from wild populations of O. rufipogon in Asia. O. rufipogon and O. meridionalis are the only AA genome species found within Australia and occur as widespread populations across northern Australia. The chloroplast genome sequence of O. rufipogon from Asia and Australia and O. meridionalis and O. australiensis (an Australian member of the genus very distant from O. sativa) was obtained by massively parallel sequencing and compared with the chloroplast genome sequence of domesticated O. sativa. Oryza australiensis differed in more than 850 sites single nucleotide polymorphism or indel from each of the other samples. The other wild rice species had only around 100 differences relative to cultivated rice. The chloroplast genomes of Australian O. rufipogon and O. meridionalis were closely related with only 32 differences. The Asian O. rufipogon chloroplast genome (with only 68 differences) was closer to O. sativa than the Australian taxa (both with more than 100 differences). The chloroplast sequences emphasize the genetic distinctness of the Australian populations and their potential as a source of novel rice germplasm. The Australian O. rufipogon may be a perennial form of O. meridionalis.     

Post-fire succession in the northern jarrah forest of Western Australia

Post-fire species changes were documented over a portion of the northern section of the jarrah forest of Western Australia from a series of sites of known age since last fire. Species richness and species diversity were observed to increase following fire for several years, followed by a gradual decline. Dominance-diversity curves indicated that maximum diversity occurred from 3 to 5 years following fire. The species composition of sites of different regions was more similar than sites of similar time since burn. The significance of the results to the programme of controlled burns is discussed.     

DESCRIPTION OF THE CALIGINOSUM SPECIES GROUP OF THE GENUS PISON JURINE (HYMENOPTERA: SPHECIDAE: LARRINAE)

A new species group of Pison (comprising P. caliginosum Turner from Australia and Norfolk I., P. mandibulatum Turner from southwestern Australia, and P. pyrrhicum sp.n. and P. weiri sp.n. from northern Australia) is recognised. A lectotype is selected for P. mandibulatum . All species possess an apically broad mandible unique within the genus. Nothing is known of the nesting biology of these species.     

Stock discrimination and movements of narrow‐barred Spanish mackerel across northern Australia as indicated by parasites

The parasite fauna of Spanish mackerel Scomberomorus commerson from 10 sites across northern Australia and one site in Indonesia, was examined to evaluate the degree of movement and subsequent stock structure of the fish. Kupang fish (Indonesia) had very few Terranova spp., Grillotia branchi , Otobothrium cysticum or Pterobothrium sp. compared to Australian fish, indicating that no Australian fish enter the Kupang fishery. Univariate and discriminant function analysis of four 'temporary' parasite species, the copepod Pseudocycnoides armatus and the monogeneans Gotocotyla bivaginalis , Pricea multae and Pseudothoracocotyla ovalis , demonstrated little similarity between areas of northern Australia, indicating minimal short‐term exchange between neighbouring groups of S. commerson . Analyses of five 'permanent' parasite species, the larval helminths G. branchi , O. cysticum , Pterobothrium sp., Callitetrarhynchus gracilis and Paranybelinia balli , also revealed large differences between areas thus indicating long‐term separation. There are at least six parasitological stocks across northern Australia: Fog Bay/Bathurst Island, Cape Wessel, Groote/Sir Edward Pellew, Mornington Island, Weipa, and the Torres Strait. The occurrence of a few irregular fish in the samples suggested that up to 5% of fish moved between stocks during their lifetime. The similarity of within‐school variability to that between schools showed that the fish do not form long‐term school associations.     

Patterns of molecular diversity in wild stocks of the redclaw crayfish (Cherax quadricarinatus) from northern Australia and Papua New Guinea: impacts of Plio-Pleistocene landscape evolution

1. Analysis of mitochondrial and nuclear DNA (microsatellites) in 379 individuals, collected from 15 localities in northern Australia and Papua New Guinea (PNG), demonstrated that wild redclaw crayfish ( Cherax quadricarinatus ) populations consist of two highly divergent Australian lineages and two PNG lineages.
2. The disjunction between the two Australian lineages occurs over a distance of approximately 200 km in the south-western corner of the Gulf of Carpenteria. These data conflict with an earlier study that detected no significant differentiation in 23 variable allozyme loci in redclaw sampled from northern Australia, but concur broadly with the previous recognition of two morphologically distinct species ( C. quadricarinatus and C. bicarinatus ) across northern Australia, and a third species in PNG ( C. albertsii ).
3. The inferred timing and patterns of divergence evident in the molecular data presented here closely align with a similar pattern reported in a co-distributed freshwater decapod crustacean, and broadly reflect patterns in some vertebrate taxa with similar distributions across northern Australia and PNG.
4. These congruent patterns most probably reflect periodic Plio-Pleistocene land and freshwater connections between Australia and New Guinea.     

The synonymy and distribution of the crenaticeps-group of Atractomorpha Saussure, 1862 (Orthoptera, Acridoidea, Pyrgomorphidae)

The general distribution of Atractomorpha australis Rehn, A. similis Bolívar and A. crenaticeps (Blanchard) in Australia and the South Pacific is discussed. Detailed synonymies and lists of known localities are given for each species, together with a distribution map. A. australis is confined to cooler, moister regions of Australia from eastern Victoria to south-western Queensland; A. similis is more tropical, occurring in the southern Moluccas, Timor, southern New Guinea and associated islands to northern and eastern Australia, but it extends, in suitable localities, as far south as central New South Wales, and, in inland areas, even to north-western Victoria and south-eastern South Australia; A. crenaticeps , formerly thought to embrace both the above species, is restricted to the northern Moluccas, western and other parts of New Guinea north of and including the central mountain chains and associated islands to the north and west, and to the Bismarck Archipelago and the Solomon Islands.     

Comparative studies on the timing of reproduction and foetal number in six species of Australian conilurine rodents (Muridae: Hydromyinae)

The timing of reproduction and number of foetuses in the wild caught conilurine rodents Notomys mitchelli, N. alexis, Pseudomys albocinereus, P. hermannsburgensis, P. delicatulus and P. nanus was ascertained from museum preserved specimens. The two species from southern Australia ( N. mitchelli, P. albocinereus ) appeared to have a breeding season from late winter to early summer, whereas in those from the central region ( N. alexis and P. hermannsburgensis ) no such breeding season was evident. The little data available for the northern species, P. delicatulus , suggests at least reproduction during the winter. Foetal number was similar for the four species from southern and central Australia but tended to be slightly less in the two northern species. The significance of these findings in relation to the control of reproduction is briefly discussed.     

Systematics of the Burmannia coelestis complex (Burmanniaceae)

Patterns of morphological variation in the Burmannia coelestis species complex are investigated, and three distinct species recognized. Burmannia coelestis sensu stricto (widespread in Asia, extending from eastern Nepal and Assam to New Guinea and northern Australia) possesses outer perianth lobes with conspicuous double margins running the entire lengths of the lobes. The name B. chinensis is revived for specimens from north-eastern India, southern China, northern Indochina and northern Thailand which possess outer perianth lobes with single margins or short double margins. A new species, B. filamentosa , is described from Guangdong province, China; it is distinctive in possessing narrow triangular outer and inner perianth lobes, and stamens with prominent filaments.     

Spatial subdivision among assemblages of Spanish mackerel, Scomberomorus commerson (Pisces: Scombridae) across northern Australia: implications for fisheries management

Aim This study investigated the use of stable δ¹³C and δ¹⁸O isotopes in the sagittal otolith carbonate of narrow‐barred Spanish mackerel, Scomberomorus commerson, as indicators of population structure across Australia. Location Samples were collected from 25 locations extending from the lower west coast of Western Australia (30°), across northern Australian waters, and to the east coast of Australia (18°) covering a coastline length of approximately 9500 km, including samples from Indonesia. Methods The stable δ¹³C and δ¹⁸O isotopes in the sagittal otolith carbonate of S. commerson were analysed using standard mass spectrometric techniques. The isotope ratios across northern Australian subregions were subjected to an agglomerative hierarchical cluster analysis to define subregions. Isotope ratios within each of the subregions were compared to assess population structure across Australia. Results Cluster analysis separated samples into four subregions: central Western Australia, north Western Australia, northern Australia and the Gulf of Carpentaria and eastern Australia. Isotope signatures for fish from a number of sampling sites from across Australia and Indonesia were significantly different, indicating population separation. No significant differences were found in otolith isotope ratios between sampling times (no temporal variation). Main conclusions Significant differences in the isotopic signatures of S. commerson demonstrate that there is unlikely to be any substantial movement of fish among these spatially discrete adult assemblages. The lack of temporal variation among otolith isotope ratios indicates that S. commerson populations do not undergo longshore spatial shifts in distribution during their life history. The temporal persistence of spatially explicit stable isotopic signatures indicates that, at these spatial scales, the population units sampled comprise functionally distinct management units or separate ‘stocks’ for many of the purposes of fisheries management. The spatial subdivision evident among populations of S. commerson across northern and western Australia indicates that it may be advantageous to consider S. commerson population dynamics and fisheries management from a metapopulation perspective (at least at the regional level).     

Correlates of Recent Declines of Rodents in Northern and Southern Australia: Habitat Structure Is Critical

Australia has experienced dramatic declines and extinctions of its native rodent species over the last 200 years, particularly in southern Australia. In the tropical savanna of northern Australia significant declines have occurred only in recent decades. The later onset of these declines suggests that the causes may differ from earlier declines in the south. We examine potential regional effects (northern versus southern Australia) on biological and ecological correlates of range decline in Australian rodents. We demonstrate that rodent declines have been greater in the south than in the tropical north, are strongly influenced by phylogeny, and are consistently greater for species inhabiting relatively open or sparsely vegetated habitat. Unlike in marsupials, where some species have much larger body size than rodents, body mass was not an important predictor of decline in rodents. All Australian rodent species are within the prey-size range of cats (throughout the continent) and red foxes (in the south). Contrary to the hypothesis that mammal declines are related directly to ecosystem productivity (annual rainfall), our results are consistent with the hypothesis that disturbances such as fire and grazing, which occur in non-rainforest habitats and remove cover used by rodents for shelter, nesting and foraging, increase predation risk. We agree with calls to introduce conservation management that limits the size and intensity of fires, increases fire patchiness and reduces grazing impacts at ecological scales appropriate for rodents. Controlling feral predators, even creating predator-free reserves in relatively sparsely-vegetated habitats, is urgently required to ensure the survival of rodent species, particularly in northern Australia where declines are not yet as severe as those in the south.     

Rapid recovery of mammal fauna in the central Kimberley,northern Australia,following the removal of introduced herbivores

Australia has lost more native mammal species than any other country in the past two centuries, and this record of loss looks likely to worsen over the next few decades. Small‐ to medium‐sized mammals are declining in both distribution and density across large tracts of northern Australia's tropical savannas, including within protected areas. The most likely causes are a combination of changed fire patterns, the impacts of introduced herbivores and predation by feral cats. Here, in contrast to the prevailing trend across northern Australia, we report the recovery of native mammals in response to a large‐scale (>40 000 ha) destocking experiment carried out at Mornington Wildlife Sanctuary in the central Kimberley, north‐west Australia. Following the removal of introduced herbivores from 2004, the species richness and abundance of small native rodents and dasyurids increased significantly across all sampled habitats over the next 3 years. We discuss the implications of these results for guiding land management and applied research to help to reduce the impending risk of mammalian extinctions in northern Australia.     

Collection of Trichogramma Westwood (Hymenoptera: Trichogrammatidae) from tropical northern Australia: a survey of egg parasitoids for potential pest insect biological control in regions of proposed agricultural expansion

Abstract  Trichogramma limit pest damage to crops by killing the developing embryo of their insect host at the egg stage. Their impact on the potentially insecticide resistant species, Helicoverpa armigera (Hübner), is considered integral to the resistance management plan for transgenic cotton production in the Ord River Irrigation Area in northern Western Australia. The dominant species of egg parasitoid in Ord River Irrigation Area cotton crops is the introduced Trichogramma pretiosum (Riley). Surveys of similar northern Australian regions earmarked for agricultural expansion revealed that T. pretiosum has been introduced, or has adventitiously dispersed, to all developing agricultural regions of northern Australia. Several previously unsequenced species were collected during surveys in more pristine habitats. Trichogramma pretiosum demonstrates an apparent ability to supersede native Trichogramma species and is perhaps favoured by agricultural expansion.     

The Gyratrix hermaphroditus species complex (Kalyptorhynchia: Polycystididae) in marine habitats of eastern Australia

A karyological and morphological analysis of 97 specimens from eastern Australia belonging to the Gyratrix hermaphroditus species complex was performed. Based on karyotype and on details of sclerotized structures of the copulatory organ, the existence of at least eight sibling species in eastern Australia could be recognised. Some of the siblings have a wide distribution across eastern and northern Australia. Populations of wide-ranging species often showed degrees of karyological and morphological differentiation. The diversity of the group is particularly high in tropical Australia. Distribution of siblings appears to be affected by ecological and physical barriers, and determined by sediment texture. This revised version was published online in July 2006 with corrections to the Cover Date.     

Review of Australian Asperoseius Chant, Euseius Wainstein, Okiseius Ehara and Phytoscutus Muma (Acari: Mesostigmata: Phytoseiidae) with a key to the genera of Australian Amblyseiinae and descriptions of two new species

Previous workers have used a conservative generic classification of the subfamily Amblyseiinae that treated most Australian Phytoseiidae as species in the genus Amblyseius Berlese. However, this lumping masks the occurrence of a number of genera recognised overseas, including some that contain important biological control agents. In this review, a key to the genera of Australian Amblyseiinae is provided and the Australian species in four amblyseiine genera are reviewed and keyed. Asperoseius Chant is represented by a single known Australian species, A. australiensis Fain and Krantz collected from a Culicoides midge in South Australia. Six species of Euseius Wainstein are recognised in Australia, including four endemics: E. dowdi (Schicha), E. elinae (Schicha), E. neovictoriensis (Schicha), and E. victoriensis (Schicha), and two Asia–Pacific species: E. noumeae (Schicha) and E. ovalis (Evans). Okiseius Ehara is represented in Australia by the previously described O. morenoi Schicha and O. domatorum (Schicha); the Asian species O. subtropicus Ehara (new record); and two new species, O. tribulation and O. cowbay described from tropical rainforest in Far North Queensland. Phytoscutus acaridophagus Collyer, a mite described from New Zealand, is reported in association with acarid mites ( Neotropacarus sp.) in Victoria and in Queensland.     

A new species of Platysace (Apiaceae) from Northern Australia

A new species of Plafysace, P saxatilis is described. The species is confined to sandstone gorges in northern Western Australia and the Northern Territory.     

A new species and a new subspecies of the stargazer genusGnathagnus from Northwestern Australia

Heretofore the genusGnathagnus (Uranoscopidae) has been composed of three species:G. elongatus (Temminck et Schlegel) from northern Australia to Japan,G. innotabilis (Waite) from Australasia, andG. egregius (Jordan et Thompson) from the western Atlantic Ocean. In this paper, a new species and a new subspecies from northwestern Australia are described and a key to the known species and subspecies of the genus is presented.     

Helminth communities of pademelons, Thylogale stigmatica and T. thetis from eastern Australia and Papua New Guinea

Gastrointestinal helminths were collected from pademelons of the genus Thylogale (Marsupialia: Macropodidae) in eastern Australia and Papua New Guinea. Examined were 12 Thylogale stigmatica stigmatica and 13 T. s. wilcoxi, the latter subdivided into eight specimens from the northern limit of their distribution and five from southern areas, all from eastern Queensland, Australia, one T. s. oriomo from Papua New Guinea and ten T. thetis from southeastern Queensland and northern New South Wales, Australia. Six species of cestodes and 40 species of nematodes were found. The helminth community of T. s. stigmatica was similar to that found in northern specimens of T. s. wilcoxi, while differences from the helminth community present in southern T. s. wilcoxi could be accounted for by parasites acquired from sympatric T. thetis. Thylogale thetis harboured a community of helminths distinct from but related to that in T. stigmatica. The evidence suggests that all subspecies of T. stigmatica examined share a common helminth community, but that in areas of sympatry, T. stigmatica and T. thetis share some of their parasites.