Inhibition of amylases from different origins by albumins from the wheat kernel.

The amylase activity of water extracts from 18 insect species, from 23 marine species and from 17 different species of birds and mammals was determined quantitatively. The inhibition of amylase in these extracts by three albumin fractions from the mature wheat kernel, which had been separated according to their molecular weights (60 000, 24 000 and 12 500 D), was determined as well. The inhibition activity of the three albumin fractions toward amylases extracted from a number of cereal species or from immature and germinating wheat kernel was also tested. The extracts from insects that are destructive of wheat grain and stored wheat products showed much higher amylase activities as compared to the other insect species that do not attack wheat and wheat products. On the basis of the effectiveness with which the three albumin fractions inhibit their activities, the amylase preparations tested were divided into susceptible, partially susceptible and resistent. Susceptible amylases, inhibited by any of the three albumin fractions, were found mainly in insects that attack wheat and in marine species. Partially susceptible amylases, inhibited by only one or two of the three albumin fractions, were present in a few avain and mammalian species including man. Resistent amylases were largely distributed in cereal, avian and mammalian species as well as in insect species that do not usually attack wheat grain or wheat flour products. At no stage of development, wheat alpha-amylase was inhibited by the albumin fractions from the mature kernel. The 12 500 dalton albumin fraction was the most effective in inhibiting insect amylases, but it was inactive toward avian and mammalian amylases. The 24 000 dalton albumin fraction was the most effective in inhibiting amylases from marine avian and mammalian species and inhibited as much as 33 amylases over 66 different amylases tested. It is suggested that protein inhibitors of amylase contributed to natural selection of polyploid wheats by giving some insect resistence to such wheats, even though some insect species were able to overcome this biochemical defense toa large degree by producing higher amylase activities.     

Local filters limit species diversity,but species pools determine composition

In a series of three experiments, we tested for effects of species pools, resource stress, and species interactions on four aspects of community structure: species richness, evenness, species composition, and functional group composition. We also examined whether the impacts of species interactions on the community varied with resource availability or species pool. Communities of sand dune annuals grew from seed bank samples collected from two sites in three different years, so that the species pool differed at two levels: the source site and the year of seed bank collection. Communities experienced one of three irrigation treatments and a range of sowing densities, which varied resource supply (stress) and the potential for species interactions, respectively.Species richness and evenness were most affected by local factors: higher densities and lower water availability decreased species diversity. In contrast, species composition was influenced most by the species pool. Functional group composition had an intermediate response, and was affected by both species pools and local filters.Resource stress and species interactions strongly filtered species from the community, but the identity of species remaining was variable. Furthermore, the magnitude of species interaction effects on richness and evenness varied with species pools. Thus, the outcome of species sorting among biotic and abiotic environments was dependent on the pool of available species. Contrary to predictions from theory, the effects of species interactions on the community did not vary consistently with resource levels.     

Fruit sizes and the structure of frugivorous communities in a New Guinea lowland rainforest

A community of frugivorous insects was studied by rearing of 25 565 individual insects representing three orders (Coleoptera, Lepidoptera and Diptera except Drosophilidae) from 326 woody plant species in a lowland rainforest in Papua New Guinea. Fruits from 19.3% of plant species were not attacked by any insect order, 33.4% of plant species were attacked by a single order, 30% by two orders and 17.2% by all three orders. The likelihood of attack by individual orders was positively correlated so that a higher proportion of plant species than expected suffered either no attack at all or was attacked by all three insect orders. Fruits from most of the plant species exhibited low rates of attack and low densities of insects. One kilogram of fruit was attacked on average by 11 insects, including three to four Coleoptera, six Diptera and one Lepidoptera. Thus, we reared on average one insect from 10 fruits, including one Diptera from 14 fruits, one Coleoptera from 22 fruits and one Lepidoptera from 100 fruits. Only 72 out of the 326 plant species hosted more than one insect per 10 fruits, and only seven species supported a density of greater than one insect per fruit. Our results suggest that specialized insect seed predators are probably too rare to maintain the diversity of vegetation by density‐dependent mortality of seeds as suggested by the Janzen–Connell hypothesis. Fruit weight, fruit volume, mesocarp volume, seed volume and fleshiness had no significant effect on the probability that a fruit would be attacked by an insect frugivore. However, fruits attacked by Diptera were significantly larger and had larger volume of both mesocarp and seeds than fruits attacked by Coleoptera and Lepidoptera.     

Examination of the structure of amylopectin molecules by fluorescent labeling

Amylopectin molecules from rice, maize, sweet potato and potato were examined by fluorescent labeling followed by gel-permeation HPLC. The number-average degree of polymerization (dp(n)) was determined to be in range of 9600-15,900. The molar-based distribution revealed the presence of three molecular species, large (dp(n) 13,400-26,500), medium (4400-8400) and small (700-2100). Their molar proportions differed by plant origin. The large species was a major component (43-63% by mole). A relatively large amount of the medium (16-28% by mole) and small (19-38%) species was found although their weight proportion was small (8-15, 1-4%, respectively). The three species from waxy rice amylopectin had a similar chain-length distribution and also a similar size-distribution of C chains. These results suggested that the three species were basically similar in cluster structure but different in number of clusters per molecule.     

PCR detection of dinoflagellate cysts in field sediment samples from tropic and temperate environments

Species-specific primers were constructed for Scrippsiella trochoidea, Protoceratium reticulatum and Lingulodinium polyedrum, which all are common cosmopolitan cyst forming dinoflagellates. The designed primers amplified a product of expected size from cultured planktonic cells of the three species, and did not yield any product with a wide range of other algal species used as negative controls. The PCR method for detection and identification of dinoflagellate cysts from the three species was applied on field samples. Undisturbed surface sediment was collected along the southwest coast of India and the west coast of Sweden. DNA extract from sediment including DNA from dinoflagellate cysts could be obtained after repeated grinding with mortar and pestle under liquid nitrogen followed by microwave boiling. All sediment samples that contained any of the target species as confirmed by microscopy, were also positive for PCR. Field samples negative for any of the target species by microscopy, were also negative by PCR. Restriction enzyme digestion and/or DNA sequencing confirmed the specificity of all the PCR products from field samples. The yield of DNA from sediment extraction was low, and therefore nested PCR was necessary for accurate species-specific detection of the three species in most of the field samples.     

Vitelline-coat lysin: Comparison of lysins among three species in the genus Tegula

Vitelline-coat lysins from two species of marine mollusc of the genus Tegula, Tegula lischkei and Tegula sp., were purified and their properties compared with those of Tegula pfeifferi. Cross-reaction tests among these three species proved that the lysin action on the vitelline coat was species specific. Each of the lysins from these three species is a single, basic polypeptide with a molecular weight of 16000-17000 and an isoelectric point of pH 10.5. All of them share a common antibody recognition site(s) for the anti-T. pfeifferi lysin antibody. Their amino acid sequences were analyzed using intact lysins and peptides separated by reverse phase high-performance liquid chromatography after V8 proteinase digestion. The amino acid sequences of the N-terminus (Nos 1-66) from the three species showed 98% homology, and those of the C-terminus (Nos 91-118) showed 89% homology. It was concluded that the species specificity of the vitelline coat lysin appears to be determined by a sequence of 24 residues (Nos 67-90) in the middle region of the molecule.     

Collembola as alternative prey sustaining spiders in arable ecosystems: prey detection within predators using molecular markers

Collembola comprise a major source of alternative prey to linyphiid spiders in arable fields, helping to sustain and retain these predators as aphid control agents within the crop. Polymerase chain reaction primers were developed for the amplification, from spider gut samples, of DNA from three of the most abundant species of Collembola in wheat crops in Europe, namely Isotoma anglicana, Lepidocyrtus cyaneus and Entomobrya multifasciata. The primers amplified fragments of the mitochondrial cytochrome oxidase subunit I (COI) gene and were designed following alignment of comparable sequences for a range of predator and prey species. Each of the primer pairs proved to be species-specific to a Collembola species, amplifying DNA fragments from 211 to 276 base pairs in length. Following consumption of a single collembolan, prey DNA was detectable in 100% of spiders after 24 h of digestion. We report the first use of DNA-based techniques to detect predation by arthropods on natural populations of prey in the field. All three species of Collembola were consumed by the spiders. By comparing the ratios of the Collembola species in the field with the numbers of spiders that gave positive results for each of those species, it was possible to demonstrate that the spiders were exercising prey choice. Overall, a single target species of Collembola was eaten by 48% of spiders while a further 16% of spiders contained DNA from two different species of Collembola. Preference was particularly evident for I. anglicana, the species most frequently found in spider guts yet the least numerous of the three target species in the field.     

Fine-scale comparative phylogeography of a sympatric sister species triplet of subterranean diving beetles from a single calcrete aquifer in Western Australia

Calcrete aquifers in the arid Yilgarn region of central Western Australia are a biodiversity hotspot for stygofauna. A distinct pattern of interspecific size class variation among subterranean dytiscid beetle species has been observed in 29 of these aquifers where either two or three small, medium and/or large sympatric species are found that are in some cases sister species. We used a 3.5 km² grid of bores to sample dytiscids on a fine-scale and employed a comparative phylogeographical and population genetic approach to investigate the origins of a sympatric sister species triplet of diving beetles from a single aquifer. Mitochondrial DNA sequence data from the Cytochrome oxidase c subunit I gene revealed that all three species have high levels of haplotype diversity with ancient (∼1 million years ago) intra-specific coalescence of haplotypes, but low levels of nucleotide diversity. Population analyses provide evidence for multiple expansion events within each species. There was spatial heterogeneity in the distribution of genetic variation and abundance both within and among the three taxa. Population analyses revealed significant fine-scale differentiation with isolation by distance for Paroster macrosturtensis and P. mesosturtensis , but not the smallest species P. microsturtensis . Haplotype network analyses provided limited or no evidence for past population fragmentation within the large and small species, but substantial historical divergence was observed in P. mesosturtensis that was not spatially structured. A patchy population structure with contemporaneous and historical isolation by distance in the three species is likely to have been a significant isolating and diversifying force, preventing us from ruling out a potential role for allopatric divergence during speciation of this beetle sister triplet.     

Low beta diversity of ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) in lowland rainforests of Papua New Guinea

We assessed the effect of geographical distance on insect species turnover in a situation where other major environmental factors, including host plant species, altitude, and climate, were constant. We sampled ambrosia beetles (Coleoptera, Curculionidae: Scolytinae and Platypodinae) from four tree species: Artocarpus altilis , Ficus nodosa , Leea indica and Nauclea orientalis , at three sites forming a 1000 km transect in lowland rainforests of northern Papua New Guinea. A standardized volume of wood from trunk, branches and twigs was sampled for ambrosia beetles from three individuals of the four tree species at each site. Each tree was killed standing and left exposed to beetle colonization for 20 days prior to sampling. We obtained 12 751 individuals from 84 morphospecies of ambrosia beetles. We surveyed most of the local species richness at each site, predicted by Chao 2 species richness estimates. The similarity of ambrosia beetle communities, estimated by Chao-Sorensen index, was not correlated with their geographical distance. Likelihood analysis and Q-mode analysis using Monte Carlo-generated null distribution of beetles among sites supported the hypothesis that the assemblages of ambrosia beetles at different sites are drawn from the same species pool, regardless of their geographical distance. Tree part (trunk, branch, or twig) was more important predictor of the composition of ambrosia beetle communities than was the host species or geographical location. All three variables, however, explained only a small portion of variability in ambrosia assemblages. The distribution of ambrosia beetles among tree parts, tree species and study sites was mostly random, suggesting limited importance of host specificity or dispersal limitation.     

Ant diversity and bio-indicators in land management of lac insect agroecosystem in Southwestern China

The segregation of land-use intensity signifies an important change in land use in lac insect agroecosystem of Southwestern China. Farming conversions have led to a highly diversified landscape, with a mosaic made up of patches of land with different succession, from cultivated lands to closed forest. Our aim here is to characterize ant assemblages within this mosaic and identify key ant community metrics and species that can be used for bioindication. The habitats supported different level of ant species richness and abundance. For ants captured by pitfall trapping, the mean plot species richness in lac plantation was significantly higher than that in dry land (deforestation land-use). For ants captured by sweep netting and foliage shaking, there was significant difference among lac plantation, dry land and secondary forest occurring from afforestation of lac plantations, with lac plantation having greatest species richness. Ant species composition was different among the three land-use habitats. Seven of the fifteen most common species had statistically different abundances or occurrence within the three land-uses. Thirteen species had statistically significant different distributions among land-use habitats (among them three species were captured by sweep netting and foliage shaking). Ten species had statistically significant habitat associations determined by IndVal analysis. Among these ten species, five ant species were associated with secondary forest, two with lac plantation, and three with dry land. Lac plantation integrated with lac-production and farming is clearly an important land-use protecting ant diversity, and thus having great conservation potential. The use of ants as bio-indicators is a promising method for determining ecological responses to human land use in China.     

连褶金小蜂属分类研究（膜翅目：小蜂总科：金小蜂科）

本文研究了我国金小蜂科的一新纪录属,连褶金小蜂属Ｌｙｕｂａｎａ Ｂｏｕｃｅｋ,描述了３个新种：廖氏连褶金小蜂Ｌ．ｌｉａｏｉ ｓｐ．ｎｏｖ．、长腹连褶金小蜂Ｌ．ｌｏｎｇａ ｓｐ．ｎｏｖ．和长节连褶金小蜂Ｌ．ｐｒｏｌｏｎｇａｔａ ｓｐ．ｎｏｖ．。模式标本存于中国科学院动物研究所动物标本馆。     

DNA-based analysis of planktonic methanotrophs in a stratified lake

1. The assemblage of planktonic methanotrophs in a stratified freshwater lake was investigated. Vertical patterns were analysed by denaturing gradient gel electrophoresis, using the primer pair specific for 16S rRNA genes of type I methanotrophs.
2. The resulting banding patterns could be divided into three distinct groups, and sequenced bands were all related to the Methylobacter species. No amplicon was obtained with the primer pair specific for type II methanotrophs.
3. Cloning analysis of the pmoA gene was performed using samples from three water depths (epilimnion, metalimnion and hypolimnion). The compositions of the clone libraries from the three depths were distinct from each other but all three libraries were dominated by clones related to Methylobacter species.     

Elementary chain composition of guinea pig thyroglobulin.

Thyroglobulin obtained from guinea pigs was examined by Na dodecyl-SO4-polyacrylamide gel electrophoresis after reduction and alkylation. In contrast to thyroglobulin from other mammalian sources, only three groups of polypeptide chains accounted for 95% or more of the protein. Determinations of the molecular weights of these purified proteins by equilibrium centrifugation in 6 M guanidine HCl gave values of 295,000 (species A), 210,000 (species B), and 110,000 (species C). Molecular weights determined by gel filtration in 6 M guanidine HCl gave similar results. Due to the large size of the polypeptides, satisfactory molecular weights could not be obtained from Na dodecyl-SO4-polyacrylamide gel electrophoresis. Amino acid analysis of the three species was similar to that of whole thyroglobulin. Only slightly higher level of lysine and histidine and a lower level of glutamic acid were seen in species C. The iodine contents were found to range from 0.07 to 0.12 to 0.20% for species A, B, and C, respectively.     

Single-strand conformational polymorphism analysis of the ribosomal internal transcribed spacer 1 for rapid species identification within the genus Pythium

Single-strand conformational polymorphism (SSCP) of the ribosomal internal transcribed spacer 1 (ITS-1) was characterized for 58 isolates of Pythium, representing 41 species from the five groups of Plaats-Niterink. Thirty-one species each produced a distinct SSCP pattern. Three species produced more than one unique pattern, corresponding to morphological subgrouping. The remaining seven species produced three distinct patterns with two or three morphologically similar species sharing a pattern. A successful blind test with four samples and the identification of eight previously unknown isolates from irrigation water demonstrated the reliability of this technique for species identification. Each SSCP pattern was defined and described by the positions of the top and bottom bands and the number of bands in between, which allows laboratories to use this technique without need to access the type isolates of Pythium species.     

Molecular phylogenies reveal host-specific divergence of Ophiocordyceps unilateralis sensu lato following its host ants

Ophiocordyceps unilateralis (Hypocreales, Ascomycetes) is an entomopathogenic fungus specific to formicine ants (Formicinae, Hymenoptera). Previous works have shown that the carpenter ant Camponotus leonardi acts as the principal host with occasional infections of ants from the genus Polyrhachis (sister genus of Camponotus). Observations were made on the permanent plots of Mo Singto, Khao Yai National Park of Thailand according to which O. unilateralis was found to occur predominantly on three host species: C. leonardi, C. saundersi and P. furcata. Molecular phylogenies of the elongation factor 1-α and β-Tubulin genes indicate a separation of O. unilateralis samples into three clades, reflecting specificity to each of the three different ant species. Samples collected from P. furcata and from C. leonardi were found to form sister groups with samples from C. saundersi forming an outgroup to the latter. Additional samples collected from unidentified ant species of Camponotus and Polyrhachis were positioned as outgroups to those samples on identified species. These results demonstrate that O. unilateralis is clearly not a single phylogenetic species and comprises at least three species that are specific to different host ant species. These cryptic species may arise through recent events of speciation driven by their specificity to host ant species.     

Community organization in a recently assembled fauna: the case of Polynesian ants

The ant species inhabiting three remote Polynesian islands were censused by hand collecting techniques. Three commonly occurring species, which exhibited complementary distribution patterns, were numerically and behaviorally dominant to other species in the communities in which they occurred. Field observations and laboratory experiments showed that negative interspecific interactions were important in maintaining the exclusive territories of the dominant species. Habitat also played a role in determining the distribution of dominant species. Pairwise tests of association among all species revealed dominant species were commonly positively associated with their own non-overlapping group of subordinate species, forming a large-scale mosaic distribution pattern of dominant and subordinate species. Baiting experiments, conducted with and without the dominant species removed, demonstrated that the presence of the dominant species decreased: (1) the proportion of baits occupied by other species, and (2) overall ant species diversity, at rich food resources. In ant communities where one of the three recognized dominant species was present, the outcome of negative interspecific interactions among species was more predictable than in communities without a recognized dominant. The same patterns were evident regardless of which of the three dominant species was present in the community. These patterns of community organization observed in this relatively newly assembled fauna are very similar to those reported from studies of older ant communities in mainland areas.     

中国两栖、爬行动物更新名录

本文在2015年发表的爬行动物名录及同年《中国两栖类信息系统》发布的两栖动物名录的基础上, 通过整理新发表的分类学研究及先前名录遗漏的部分早期文献, 更新了截至2019年底中国现生本土两栖、爬行动物物种名录。2015-2019年间, 中国两栖动物新记录1科, 新描述2属, 恢复1属有效性, 新记录1属, 新描述或恢复有效种74种, 新增国家纪录18种; 另6属、8种的有效性未得到近年研究证据支持(在此视为次定同物异名而未做收录, 后同)。同期, 中国爬行动物新恢复5科, 新描述1亚科, 新描述1属, 恢复3属有效性, 新记录3属, 新描述、恢复或提升有效种43个, 新增国家纪录10种; 另有5属、4种的有效性未得到近年研究证据支持, 并移除1属、4种在我国的分布纪录。此外, 通过整理2015年前文献, 爬行动物增补3属, 提升3亚种至种级地位, 增补国家新纪录3种, 另有3属、2种的有效性未得到近年研究证据支持, 同时移除1种在我国的分布纪录。综上, 截至2019年底, 我国共记录现生本土两栖动物3目13科62属515种(蚓螈目1科1属1种, 有尾目3科14属82种, 无尾目9科47属431种), 爬行动物3目35科135属511种(鳄形目1科1属1种, 龟鳖目6科18属34种, 有鳞目蛇亚目18科73属265种、蜥蜴亚目10科43属211种)。此外, 本文还对先前名录中部分爬行动物的中文名提出了修改建议, 建议恢复部分物种的惯用中文名。2015-2019年, 新物种及新纪录已知物种数量占现两栖、爬行动物物种总数的17.1%和10.2%。近年来, 我国发表的两栖、爬行动物新物种和已知物种的新纪录数量持续增加, 分类体系也在研究中不断完善, 建议今后及时地进行阶段性总结, 同时对存在的问题提出讨论, 以推动中国两栖、爬行动物分类学研究工作的进一步开展。     

Isolation of Yersinia enterocolitica and related species from the faeces of cows

A total of 203 samples of faeces from 124 cows was examined for the presence of Yersinia enterocolitica and related species by a variety of isolation procedures. Cold enrichment at 5°C for three weeks, followed by plating on cefsulodin-irgasannovobiocin agar yielded Yersinia species most frequently. Yersinia enterocolitica or related species were isolated from 50% of the cows.     

Comparative study of the erythrocytes and haemoglobins in nototheniid fishes from Antarctica

The blood of seven Antarctic nototheniid species and representatives from three other families contained low haemoglobin concentrations compared with non-polar marine teleosts. Haematocrit values were slightly lower than values from other teleosts, while haemoglobin and erythrocyte counts were substantially reduced by comparison. Interspecific variation in haemoglobin concentration seemed to be a function of activity level. Mean corpuscular haemoglobin concentration of all Antarctic species was strikingly low by comparison with species from lower latitudes and was not correlated with the habits of the species. Haemoglobin componentry was compared using celluslose-acetate electrophoresis and, unlike many temperate species, only one major haemoprotein was isolated from each benthic species, but four components were evident in the pelagic species Trematomus borchgrevinki . The possible functional significance of these findings was discussed in relation to the ecology of each species.     

A census of a community of small terrestrial vertebrates

A small vertebrate community of eighteen terrestrial species was revealed by removal trapping in 1 ha of Western Australian Banksia woodland in autumn. Nine of these species were lizards, three were mammals, three were snakes and three were frogs. The use of pitfall and mammal traps on an 8 × 8 m grid was shown to be sufficient to census the majority of terrestrial species in the study site. A biomass of 2063 g/ha of terrestrial species was estimated from trapping records. Frogs (three species) had the greatest biomass (41% of total), but the introduced mouse Musmusculus contributed the greatest biomass (36%) of any single specie.