Biological traits of stream macroinvertebrates from a semi-arid catchment: patterns along complex environmental gradients

1. The relationships between biological traits of macroinvertebrates and environmental characteristics were investigated in streams with contrasting physical, chemical or landscape level attributes. We used an ordination technique, RLQ analysis, which links an environmental table (R) with traits table (Q) through an abundance table (L) to investigate the relationship between habitat characteristics and biological traits.
2. A major environmental axis explaining the distribution of species and their distinctive biological features was obtained. This axis included variables of anthropogenic pressure (agricultural and urban uses) and natural variability (climatic and geologic) that are strongly intercorrelated in the study area, with a clear spatial component.
3. The attributes of species from frequently disturbed systems (small size, multivoltinism, diapause, ovoviviparity, etc.) were associated with semi-arid areas whereas traits common in more stable and favourable environments (large body size, semi-voltinism, isolated eggs, etc.) were found in upland forested areas.
4. The natural climatic variation was proposed as a disturbance axis of a theoretical habitat templet (driven by the intense hydrological disturbances typical of semi-arid streams), while anthropogenic pressure (mainly intensive agriculture) and high salinity, a natural consequence of geology, was proposed as an adversity axis. Different life-histories associated with contrasting environmental features were superimposed in this habitat templet.
5. The ecological–evolutionary scenario in which stream macroinvertebrates have evolved and by which their communities are organized, is closely linked to disturbance, environmental harshness and human pressure.     

The leaf-tying moth Hypocosmia pyrochroma (Lep., Pyralidae), a host-specific biological control agent for cat's claw creeper Macfadyena unguis-cati (Bignoniaceae) in Australia

Abstract:  Cat's claw creeper, Macfadyena unguis-cati , a major environmental weed in coastal and sub-coastal areas of Queensland and New South Wales, Australia is a target for classical biological control. Host specificity of Hypocosmia pyrochroma Jones (Lep., Pyralidae), as a potential biological control agent was evaluated on the basis of no-choice and choice larval feeding and survival, and adult oviposition preference tests, involving 38 plant species in 10 families. In no-choice tests, larval feeding and development occurred only on cat's claw creeper. In choice tests, oviposition and larval development was evident only on cat's claw creeper. The results support the host-specificity tests conducted in South Africa, and suggest that H. pyrochroma is a highly specific biological control agent that does not pose any risk to non-target plants tested in Australia. This agent has been approved for field release by relevant regulatory authorities in Australia.     

Revision of the Australian Coccinellidae (Coleoptera). Part 3. Tribe Sukunahikonini

Abstract  The Australian members of the circumtropical coccinellid tribe Sukunahikonini are revised and placed in three genera: Scymnomorphus Weise (five species), Pharellus Sicard (two species) and Paraphellus Chazeau (two species). Scymnus rostratus Lea, 1929 is transferred to Paraphellus as P. rostratus (Lea) comb. n. The following new species are described from Australia: Pharellus glabratus sp. n., P. popei sp. n.; Paraphellus magnopunctatus sp. n.; Scymnomorphus fulvus sp. n., S. hirtus sp. n., S. ker sp. n., S. luteus sp. n., S. storeyi sp. n. Nomenclatural history, diagnoses and distribution are provided for each species. Keys to the genera and species are included.     

Parasitism of the lucerne pest Sitona discoideus Gyllenhal (Coleoptera: Curculionidae) and non-target weevils by Microctonus aethiopoides Loan (Hymenoptera: Braconidae) in south-eastern Australia, with an assessment of the taxonomic affinities of non-target hosts of M. aethiopoides recorded from Australia and New Zealand

Abstract  The braconid parasitoid Microctonus aethiopoides Loan has been released in Australia and New Zealand for biological control of the lucerne pest Sitona discoideus Gyllenhal. In New Zealand, the parasitoid attacks a number of endemic weevil species. A survey of Curculionoidea found in and near lucerne in south-eastern Australia was carried out to investigate whether similar non-target parasitism was occurring, and to relate this to levels of parasitism found in the target host, S. discoideus . Some of the original M. aethiopoides release sites were particularly targeted in the survey of 25 sites in Victoria, New South Wales and South Australia. Almost 2500 weevils were collected, of which over 90% were S. discoideus , with the remaining 197 other weevils comprising 29 species found at 15 of the 25 sites. Parasitism of S. discoideus by M. aethiopoides occurred at 12 lucerne sites, with levels ranging from 0 to 25%. A single incidence of parasitism of a species of an Australian native weevil Prosayleus sp. by M. aethiopoides was recorded. No parasitism of any other weevil species was observed. The taxonomic affinities between Sitona and native Australian and New Zealand weevils are discussed, concluding that non-target host range in M. aethiopoides may be determined more by ecological factors than by taxonomic affinities among its hosts.     

柱花草种质资源研究进展

柱花草属(Stylosanthes Sw.)约含50个种(包括二倍体和多倍体), 染色体基数x=10, 是热带和亚热带地区的优良豆科牧草, 其中圭亚那柱花草(S. guianensis Sw.)、有钩柱花草(S. hamata (L.) Taub.)、西卡柱花草(S. scabra Vog.)、矮柱花草(S. humilis Kunth)和灌木柱花草(S. seabrana B. L. Maas s & 't Mannetje)的种植面积最广。由于柱花草产量高、营养丰富、栽培容易且用途广泛(可用于青稞饲料、调制干草和干草粉、牧地种植、果树间种、水土保持及绿肥等), 被许多国家用于热带和亚热带农业生产中, 如亚洲的中国、印度、泰国和马来西亚等, 澳洲的澳大利亚, 美洲的美国、哥伦比亚、巴西和古巴, 以及非洲的尼日利亚等。该文对柱花草种质资源的系统学、种质收集、评价、利用及育种等方面的研究进展进行了系统的概括和归纳, 并展望了当前柱花草研究的热点领域和亟待解决的问题。     

Studies on the Pollen Morphology of Family Salicaceae in Gansu

Pullen grains of 2 genera 31 species of the family Salicaceae ia Gansu have been investigated. The comparative studies of the pollen grains were carried out by means of seanning electron microscope and light microscope. The two genera (Popu- lus L. and Salix L.) can be distinguished by their pollen characters such as the shape of pollen, type of aper ure, ornamentation of exine etc. 1. Shape of pollen grains 1) Spherical (rounded) : Populus L., 2) Ellipoidal, (subrotund): Salix L. 2. Type .of aperture 1) Atreme: Populus L., 2) 3-colpate, 3-colporoidate or 3-syncolpate: Salix L. 3. Ornamentation of exine 1 ) Cavernulous: Populus L., 2) Tubercular: Populus L., 3) Spinulate: Salix L., 4) Rugulose: Populus L. and Salix L., 5) Finely-reticulate: Populus L., 6) Reticulate: Salix L., 7) Crass-reticulate: Salix L., 8) Rugulose-Spinulate-Cavernulous: Salix L., 9) Rugulose-Reticulate: Salix L. Basing upon the above pollen characters, the genera Populus L. and Salix L. are con- sidered two good and natural taxa, and the genus Populus L. is more primitive than the genus Salix L.     

Comparative morphology of leaf epidermis of Salix (Salicaceae) with special emphasis on sections Lindleyanae and Retusae

The sections Lindleyanae C.K. Schneid. and Retusae A. Kern. are two unique taxa of Salix . Although the former is distributed in the Himalayas and in south-west China's Hengduan Mountains, and the latter in the Arctic–Alpine region, they share similar phenotypic characters. To elucidate their relationships, some representative species were selected and their leaf epidermal characters were examined. Most Salix species had broadly similar leaf epidermal cell characteristics, but Lindleyanae and Retusae shared an anomocytic type of stomatal apparatus, which differed greatly from other taxa in Salix . It is unclear whether this epidermal similarity is indicative of similar environments or a single phylogenetic origin. Within the family Salicaceae, cyclocytic stomata were present in Chosenia , but absent from Populus and Salix , partly supporting the separation of Chosenia from Salix as an independent genus. Within single Salix species, obscure interspecific phenotypes could be identified by the shape of the epidermal cells, the presence or absence of stomata on the adaxial or abaxial sides, and the shape of the anticlinal walls. Stomatal size and density in Salix varied in response to environmental factors, and was of little diagnostic value in the separation of the species.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 311–322.     

The hymenopteran parasitoids of light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae) in Australia

Abstract  Epiphyas postvittana (Walker) is a serious pest of a number of horticultural crops including grapes in Australia and New Zealand. This study brings together information on the parasitoid complex associated with E. postvittana that previously was fragmented and largely inaccessible. We include species reared during a 3-year study of the parasitoids of E. postvittana in the vineyards of the Coonawarra region, South Australia, material from several Australian agricultural insect collections and records from the literature. An illustrated key is presented for 25 species of parasitoids and hyperparasitoids associated with E. postvittana , along with information on the taxonomy, identification, distribution and biology of each species. Taxa newly recorded from this host are Perilampus sp. (Perilampidae), and six species of Ichneumonidae: Euceros sp., Labium sp., Netelia sp., Plectochorus sp., Temalucha minuta (Morley) and Eriborus epiphyas sp. n., the latter species being described in full.     

Do exotic generalist predators alter host plant preference of a native willow beetle?

1 Selection can favour herbivores that choose host plants benefitting their offspring either by enhancing growth rates or by increasing larval defences against native predators. For exotic predator species that feed on herbivores, their success with invading new habitats may depend upon overcoming defences used by native prey. Whether exotic predators can alter herbivore host choice has remained unexamined. Therefore, we compared the efficacy of larval defence by Chrysomela knabi (a native beetle species) that had fed on two native willow hosts: Salix sericea (a phenolic glycoside (PG)-rich species) and Salix eriocephala (a PG-poor species), when attacked by exotic generalist predators. In addition, the preference and performance of C. knabi on S. sericea and S. eriocephala was examined.
2  Chrysomela knabi preferred and performed better on S. sericea. In a common garden, adult C. knabi were nine-fold more common and oviposited five-fold more frequently on S. sericea than on S. eriocephala . In the laboratory, adult feeding preference on leaf discs and survival rates of larvae were both greater on S. sericea , and time to pupation was shorter.
3  Chrysomela knabi larvae produced significantly more salicylaldehyde when fed S. sericea leaves than when fed S. eriocephala leaves. Additionally, those larvae with greater salicylaldehyde had reduced predation by two exotic generalist predators, Harmonia axyridis larvae and juvenile Tenodera aridifolia sinensis .
4 The results obtained in the present study suggest that selection favoured the preference of C. knabi for PG-rich willow plants because larvae grew and survived better and that selection by common exotic generalist predators would reinforce this preference.     

8种木本植物木质部栓塞变化与生理生态指标关系的研究Ⅰ.与植物木质部水势的关系

以自然状况下生长良好的耐旱树种刺槐(Robinia pseudoacacia L.)、元宝枫(Acer truncatum Bge.)、沙棘(Hippophae rhamnoides L.)、白榆(Ulmus pumila L.)、油松(Pinus tabulaeformis Carr.)、白皮松(Pinus bungeana Zucc.ex Endl.)及中生树种女贞(Ligustrum lucidum Ait.)、柳树(Salix matsudana Koidz. f. pendula Schneid.)为研究对象,用压力室法测定木质部水势,用冲洗法测定木质部栓塞程度,研究不同生长季节木质部栓塞与水势间的关系.结果表明针叶树油松、白皮松在各季节水势均较高,水势变化幅度较小,木质部不易发生栓塞,这与其木质部由管胞构成,对木质部栓塞不敏感,在干旱时采用高水势延迟脱水的耐旱策略有关.阔叶树刺槐、元宝枫、沙棘、白榆、女贞和柳树的木质部栓塞现象是其在每天正常生长过程中不可避免的 "平常事件",是它们适应干旱的一种方式.它们的木质部栓塞程度与水势表现出了相反的变化趋势,即同一树种在同一季节内水势值越低,木质部栓塞程度越大,但在不同树种及同一树种的不同季节不存在这种关系.由此可见,植物木质部栓塞对水势的敏感程度(即木质部栓塞脆弱性)主要由树种的木质部结构决定,同时受到树种特性、树木生长发育时期、外界环境因子的影响,木质部栓塞的脆弱性也具有季节变化特征.     

Redberry mite, Acalitus essigi (Hassan) (Acari: Eriophyidae), an additional biological control agent for Rubus species (blackberry) (Rosaceae) in Australia

Abstract  Acalitus essigi , the eriophyoid mite that causes red berry disease in Rubus species (Rosaceae), was collected from the fruits of three species of weedy blackberry, R. anglocandicans , R. laudatus and R. ulmifolius , in south-west Australia. This is the first record for this species in Western Australia and these plants appear to be new host records for A. essigi , which causes uneven ripening of fruit. Information on the mite is reviewed in the context of determining its potential as a biological control agent for Rubus species, especially those that are not susceptible to Phragmidium violaceum (Uredinales), the rust fungus being released against species of European blackberry in Australia. Published records also show that A. essigi will attack a wide range of Rubus species including species of North American origin that currently escape biological control in Australia. It may also be useful for preventing the spread of commercial varieties of Rubus (e.g. raspberry and loganberry) that have escaped to become weedy. However, the mite may have limited dispersal ability and thus require redistribution.     

柱花草种质资源研究进展

柱花草属（Stylosanthes Sw.）约含50个种（包括二倍体和多倍体）,染色体基数x=10,是热带和亚热带地区的优良豆科牧草,其中圭亚那柱花草（S.guianensisSw.）、有钩柱花草（S.hamata（L.）Taub.）、西卡柱花草（S.scabra Vog.）、矮柱花草（S.humilis Kunth）和灌木柱花草（S.seabrana B.L.Maass＆＇tMannetje）的种植面积最广。由于柱花草产量高、营养丰富、栽培容易且用途广泛（可用于青稞饲料、调制干草和干草粉、牧地种植、果树间种、水土保持及绿肥等）,被许多国家用于热带和亚热带农业生产中,如亚洲的中国、印度、泰国和马来西亚等,澳洲的澳大利亚,美洲的美国、哥伦比亚、巴西和古巴,以及非洲的尼日利亚等。该文对柱花草种质资源的系统学、种质收集、评价、利用及育种等方面的研究进展进行了系统的概括和归纳,并展望了当前柱花草研究的热点领域和亟待解决的问题。     

Biological control of Ziziphus mauritiana (Rhamnaceae): feasibility,prospective agents and research gaps

The tropical fruit tree, Ziziphus mauritiana (Rhamnaceae), a native of the Indian subcontinent, is a pasture and environmental weed in northern Australia and Fiji. In their native range, Ziziphus spp., including commercially cultivated Z. mauritiana and Z. jujuba, are subjected to a wide range of pests and diseases. The feasibility of classical biological control of this weed has not been explored to date. Effective biological control could reduce plant vigour and seed output, thereby limiting the spread of Z. mauritiana in Australia. Two Ziziphus species are native to Australia, hence, any prospective biological control agent should be specific to Z. mauritiana. Opportunistic field surveys and literature searches identified 133 species of phytophagous insects, 9 species of phytophagous mites and 12 plant pathogens on Ziziphus spp. Host records suggest the following are possibly specific to Z. mauritiana and hence are prospective biological control agents in Australia: the seed‐feeding weevil Aubeus himalayanus; the leaf‐feeding gracillariid moth Phyllonorycter iochrysis; the leaf‐mining chrysomelid beetle Platypria erinaceus; the leaf‐folding crambid moth Synclera univocalis; the leaf‐galling midge Phyllodiplosis jujubae; and the gall‐mites Aceria cernuus and Larvacarus transitans. Host range of the rust Phakopsora zizyphi‐vulgaris includes many Ziziphus species, including the native Z. oenoplia and hence would not be a suitable biological control agent in Australia. The powdery mildew Pseudoidium ziziphi, with a host range restricted to Ziziphus species, has not been reported on Z. oenoplia. All available information on the pests and diseases of Z. mauritiana are from cultivated varieties. Hence, future surveys should focus on wild Z. mauritiana in the Indian subcontinent in areas that are climatically similar to the regions of northern Australia, where it is currently most abundant.     

Euro-amerikanische verwandtschaftliche Beziehungen zweier mediterraner Salix-Arten

The author shows a close affinity between Salix salviifolia Brot., widespead on the Iberian Peninsula, and the East-American Salix tristis Ait. These two species together with the European S. aurita L. and the American S. humilis Marsh. form a group of closely linked species within the subsection Leaves (section Vetrix). Salix pedicellata Desf., a species of a broad Mediterranean area, is related to West American (predominantly Californian) Salix lasiolepis Benth. This relationship is perhaps a more remote one, than in the first case, still it is hardly dubitable. S. lasiolepis with the closely related S. hookerana Barr. forms a West American link of the subsection Vulpinae, substituting here the Old World group of S. pedicellata. In the light of the available botanical evidence, a direct transatlantic origin of the described relationships seems to be more probable than the complex way of migrations across Beringia and East Asia.     

Relative importance of host tree species and environmental gradients for epiphytic species composition, exemplified by pyrenomycetes s. lat. (Ascomycota) on Salix in central north Scandinavia

According to the continuum concept of vegetation, variation in species composition is primarily determined by complex environmental gradients. Species-gradient relationships of ground-dwelling, independent organisms are studied at scales ranging from centimetres to continents. In this study we use a balanced data set for pyrenomycetes on Salix to address if how the current species-gradient paradigm needs to be modified to apply to assemblages of organisms that are dependent on other organisms for their existence. The data from a transect across central-north Scandinavia included variation along climatic gradients in oceanicity (from oceanic to continental vegetation sections), and temperatures (from south boreal to alpine vegetation zones) and among five common and widely distributed Salix host species ( Salix caprea agg., S. glauca ssp. glauca , S. lapponum , S. myrsinifolia agg. and S. pentandra ). Ten individuals of each Salix host species were selected and carefully examined for pyrenomycetes within each combination of section and zone. Data for 28 species in the 28 combinations of section, zone and host were subjected to ordination and constrained ordination analyses. Host species was the most important source of variation in species composition, followed by zone and section which are the same major regional gradients that are important to plants. We use examples to discuss the contribution of local ecological and substrate gradients to the high variation explained by host species, concluding that host specificity per se occurs for these partly parasitic fungi. We therefore suggest that in order to account for variation in composition of species assemblages with strong degree of host dependence, general rules for species-gradient relationships need to be extended by inclusion of host specificity as separate factor.     

Hosts are more important than destinations: What genetic variation in Microctonus aethiopoides (Hymenoptera: Braconidae) means for foreign exploration for natural enemies

Nucleotide sequence data were generated from the gene regions COI, 16S, and arginine kinase to assess genetic variation within the Palearctic parasitoid, Microctonus aethiopoides, reared from Sitona discoideus, S. hispidulus, and Hypera postica collected from two proximate locations in Mediterranean France. Partitioned Bayesian phylogenetic analyses of the molecular data provided strong support for the presence of at least two M. aethiopoides biotypes, one associated with Hypera species and the other with Sitona species. These new results combined with previously published data from 14 countries show that M. aethiopoides genetic variation is much more strongly correlated with host taxon than with sampling location. This contrasts with earlier perceptions that M. aethiopoides exhibits significant geographic variation, and helps to explain the widely varying biological control outcomes that have been obtained following the introductions of M. aethiopoides to Australia, New Zealand, and North America. The results strongly suggest that success rates and environmental safety in biological control would both be improved by ensuring that parasitoids collected in the native range are reared from the same host species as the one being targeted for control in the region of introduction. The results also provided insights both on the evolution of M. aethiopoides' host range, and on its evolutionary transition between solitary and gregarious larval development.     

Quarantine host range studies with Lophyrotoma zonalis, an Australian sawfly of interest for biological control of melaleuca, Melaleuca quinquenervia, in Florida, U.S.A.

The Australian melaleuca tree, Melaleuca quinquenervia (Cav.) S. T. Blake (Myrtaceae), has naturalized in southern Florida,U.S.A., and is now one of that regions most important weeds.Primarily a weed of wetlands, it also infests neighboring drierareas. Current efforts to restore the South Florida ecosystem arethreatened by the continuing range expansion of melaleuca andother weeds. In an effort to supplement the current chemical andcultural control methods for melaleuca, a search for potentialbiological control agents was begun in Australia in 1986. Thesawfly, Lophyrotoma zonalis, was determined after extensive fieldand laboratory studies to have potential as a biological controlagent. Larvae of L. zonalis eat leaves and occasionally defoliatelarge trees in Australia. Host range studies were conducted in aFlorida quarantine facility with native and cultivated plantspecies. Multi-choice and no-choice oviposition tests wereconducted with 36 species in the Myrtaceae and with 18 species inother families. Larvae developed to prepupae and adults from theeggs oviposited on 23 species of Myrtaceae only on 3 species ofbottlebrushes, Callistemon. Medium-sized larvae were tested forfeeding on bouquets of plant cuttings and on potted plants. Theyare the stage that might wander from defoliated trees. Noticeablefeeding, but much less than on melaleuca, was restricted to theMyrtaceae, except for a few individual larvae that fed on waxmyrtle, Myrica cerifera. Medium-sized larvae became prepupae onlyon Melaleuca decora (73%) and on wax myrtle (10%). However,neither species received eggs in the oviposition tests. Thesestudies confirmed the narrow host range of L. zonalis aspreviously reported from field and laboratory studies inAustralia.     

Detection of Laribacter hongkongensis using species-specific duplex PCR assays targeting the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region (ISR)

Aims: For the rapid detection of Laribacter hongkongensis, which is associated with human community‐acquired gastroenteritis and traveller’s diarrhoea, we developed a duplex species‐specific PCR assay. Methods and Results: Full‐length of the 16S–23S rRNA intergenic spacer region (ISR) sequences of 52 L. hongkongensis isolates were obtained by PCR‐based sequencing. Two species‐specific primer pairs targeting 16S rRNA gene and ISR were designed for duplex PCR detection of L. hongkongensis. The L. hongkongensis species‐specific duplex PCR assay showed 100% specificity, and the minimum detectable level was 2·1 × 10^?2 ng μl^?1 genomic DNA which corresponds to 5000 CFU ml^?1. Conclusions: The high specificity and sensitivity of the assay make it suitable for rapid detection of L. hongkongensis. Significance and Impact of the Study: This species‐specific duplex PCR method provides a rapid, simple, and reliable alternative to conventional methods to identify L. hongkongensis and may have applications in both clinical and environmental microbiology.     

No phytochelatin (PC2 and PC3) detected in Salix viminalis

Phytochelatins (PCs) have been detected in a large range of plant species, but their role in heavy-metal tolerance is unclear. Various clones of Salix viminalis are differently tolerant to heavy metals, and the aim of this work was to investigate whether PCs were differently expressed in tolerant compared with sensitive clones. In a long-term study, five clones with high or low metal tolerance were cultivated 21 days without or with Cd (1 or 10 µ M ), Cu (0.3 or 7 µ M ), Ni (15 µ M ), Pb (7 µ M ) or Zn (10 or 100 µ M ). Controls were further used in a short-term study where Cd (1 µ M ) was added and samples were collected 0, 15 and 30 min, 1, 3 and 24 h after start of treatment. PCs were analysed on high performance liquid chromatography (HPLC) using two different methods: post-column derivatization using Ellmans reagent and pre-derivatization with monobromobimane. Thlaspi caerulescens treated with Cd was used as internal PC standard. No PCs could be detected in Salix with either of the two methods in any of the treatments: different clones, metals, concentrations, plant parts or treatment time. The 16 thiol peaks shown were the same in both control and treated plants. Both HPLC methods showed PC peaks when Thlaspi was used but these peaks could not be associated with any of the 16 peaks. The amino acid composition of the 16 peaks was not the expected composition of that of PCs. Thus, Salix viminalis have no detectable levels of PCs, which in turn are not involved in heavy metal tolerance in Salix .