On the Domene species of China,with descriptions of four new species (Coleoptera,Staphylinidae)

Material of the paederine genus Domene Fauvel, 1873 from China is examined. Nine species were identified, four of them described previously, one unnamed (represented exclusively by females), and four are newly described: Domene cultrata sp. n. (Gansu, Hubei, Shaanxi); Domene cuspidata sp. n. (Gansu, Shaanxi, Sichuan); Domene chenae sp. n. (Guangxi); Domene reducta sp. n. (Sichuan). A lectotype is designated for Domene reitteri Koch, 1939; a neotype is designated for Domene chenpengi Li, 1990. Domene dersuuzalai Gusarov, 1992 is placed in synonymy with Domene chenpengi. Previous records of two Japanese species from China are most likely based on misidentifications and considered erroneous. Thus, the Domene fauna of China is currently composed of twelve described species. A key to the Domene species of China is provided. The distributions of eleven species are mapped.     

Length-weight relationships of four fish species from the Yalong River,China

Parameters of the length-weight relationship (LWR) were estimated for four fish species [Beaufortia szechuanensis (Fang, 1930), Claea dabryi (Sauvage, 1874), Percocypris pingi (Tchang, 1930), and Yunnanilus sichuanensis Ding, 1995] from the Yalong River. Samples were collected seasonally from June 2018 to July 2019, using various fishing gears [set nets (mesh: 1.5 × 2.0 cm), hook, drift gill nets (three mesh sizes: 1.0; 2.0; 3.0 cm) and electro fishing]. Two new maximum standard length were recorded for C. dabryi and P. pingi.     

Alkanes of four related moth species,Helicoverpa and Heliothis

Comparison of the presence and quantities of cuticular hydrocarbons has been used successfully for identifying sibling species and races of several groups of insects. This approach has been extended to four species of moths previously regarded as belonging to the same genus, Heliothis. Gas chromatography was used to quantify the numerous high-molecular weight alkanes found on the cuticle of two pairs of closely related species: Helicoverpa zea and Helicoverpa armigera, and Heliothis virescens and Heliothis subflexa. Both sexes of H. zea and H. armigera contained different quantities of several alkanes that could be used for unambiguous identification. Similar comparisons of H. subflexa and H. virescens showed four peak ratios that were different for each species. Sexual dimorphism was minor in H. subflexa and H. virescens.     

Breeding success of the colonist species Bubulcus ibis (Linnaeus, 1758) and four native species

This work evaluated the breeding success of Bubulcus ibis (Ardeidae), Egretta thula, Nycticorax nycticorax, Phimosus infuscatus and Plegadis chihi in Rio Grande do Sul during two consecutive nesting seasons. Mean clutch size for B. ibis was 2.59 in 1998/1999 and 2.49 in 1999/2000. The species with both the smallest and largest clutch was P. infuscatus, with 2.04 in 1999/2000, and 3.16 in 1998/1999. The highest mean number of nestlings per nest was 2.86 for P. chihi in 1998/1999 and the lowest was 1.85 for B. ibis in 1998/1999 and P. infuscatus in 1999/2000. In both nesting seasons all the species had major success, laying three eggs and raising two nestlings, exept for B. ibis. The breeding success for P. chihi varied from 1.54 young/nest in 1998/1999 to 0.4 in 1999/2000, whereas B. ibis ranged from 1.16 in the first period to 0.99 in the second.     

On the water relations of four heath species

Four species of heath, occurring in the heathlands of Brittany, are compared regarding their water relations: Calluna vulgaris, Erica ciliaris, E. cinerea and E. tetralix. E. cinerea is unable to establish itself in wet heathland because of its intolerance of prolonged waterlogging. It is the Erica species best adapted to dry habitat conditions in Brittany. E. ciliaris canot establish itself in dry heathland and is less tolerant of waterlogging than E. tetralix. E. tetralix is the species best adapted to wet heathland, being tolerant of waterlogging, but can also establish itself in dry heathland. Of the three E. species it has the widest ecological range. Calluna is tolerant of both wet and dry conditions and has a wide ecological range. E. cinerea is typical of dry- and E. tetralix of wet heathland. Although both species did best in moist aerated soil in experimental cultures, neither is abundant in mesophilic heaths where E. ciliaris is dominant. One explanation may be competition for aerial space. E. cinerea and E. tetralix both have an upright growth, whereas E. ciliaris rapidly adopts a straggling bushy habit, with long rooting branches. E. ciliaris thus establishes large interpenetrating clumps. With increasing dryness E. ciliaris disappears and may be replaced by E. cinerea and, with increasing wetness and especially waterlogging, E. tetralix will take over.     

On the Cyprideis species flock (Crustacea, Ostracoda) in Lake Tanganyika, with the description of four new species

Four new species, belonging to three genera, of ostracods from Lake Tanganyika are described: Mesocyprideis nitida sp.nov., Romecytheridea belone sp.nov., R. plegma sp. nov. and Cyprideis loricata sp. nov. The Cyprideis species flock of Lake Tanganyika now consists of 17 formally described species (16 endemic) in 6 genera (4 endemic). The geographical and ecological distribution of the four species is briefly discussed and some supplementary remarks on the radiation of the Cyprideis species flock in Lake Tanganyika are offered.     

Attraction of four entomopathogenic nematodes to four white grub species

To better understand the differences in the efficacy of entomopathogenic nematode species against white grub species, we are studying the various steps of the infection process of entomopathogenic nematodes into different white grub species using nematode species/strains with particular promise as white grub control agents. In this study we compared the attraction of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), Steinernema glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and Heterorhabditis bacteriophora (GPS11 strain) to third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis, and late-instar greater wax moth, Galleria mellonella, larvae. Individual larvae were confined at the bottom of 5.5 cm vertical sand columns, nematodes added to the sand surface after 24 h, and nematodes extracted after another 24 h. Nematode attraction to hosts was strongly affected by nematode species but the effect of insect species varied with nematode species. S. glaseri had a high innate dispersal rate (i.e., in absence of insects) and was strongly attracted to insects without significant differences among insect species. S. scarabaei had a very low innate dispersal rate so that even a strong relative response to insects resulted in low absolute dispersal rates toward insects. S. scarabaei tended to be most attracted to G. mellonella and least attracted to C. borealis. H. zealandica had a high innate dispersal rate but only responded weakly to insects without significant differences among species. H. bacteriophora had limited innate dispersal and only weakly responded to insects with G. mellonella tending to be the most attractive and C. borealis the least attractive insect. It has to be noted that we cannot exclude that the use of different rearing hosts (A. orientalis and P. japonica larvae for S. scarabaei, G. mellonella larvae for the other nematodes) might have had an impact on the nematodes dispersal and relative attraction behavior. This study indicates that host attractiveness and nematode dispersal rates may contribute but do not play a major role in the variability in white grub susceptibility and/or nematode virulence.     

Leaf growth dynamics in four plant species of the Patagonian Monte, Argentina

Studying plant responses to environmental variables is an elemental key to understand the functioning of arid ecosystems. We selected four dominant species of the two main life forms. The species selected were two evergreen shrubs: Larrea divaricata and Chuquiraga avellanedae and two perennial grasses: Nassella tenuis and Pappostipa speciosa. We registered leaf/shoot growth, leaf production and environmental variables (precipitation, air temperature, and volumetric soil water content at two depths) during summer-autumn and winter-spring periods. Multiple regressions were used to test the predictive power of the environmental variables. During the summer-autumn period, the strongest predictors of leaf/shoot growth and leaf production were the soil water content of the upper layer and air temperature while during the winter-spring period, the strongest predictor was air temperature. In conclusion, we found that the leaf/shoot growth and leaf production were associated with current environmental conditions, specially to soil water content and air temperature.     

Sterols from four species of liliaceae

Fractionation of the sterol mixture from Tristagma uniflorum, Nothoscordum gramineum var. philippianum, Nothoscordum inodorum, and Nothoscordum montevidense were achieved by means of preparative TLC. Analysis of the fractions by GC and GC-MS allowed the identification of Δ⁰, Δ⁵, and Δ⁷ sterols. The unusually high proportion of cholestan-3β-ol seems to be biogenetically related to the C₂₇ steroidal sapogenins contained in those plants.     

Integrative taxonomy of the Clavus canalicularis species complex (Drilliidae,Conoidea, Gastropoda) with description of four new species

ABSTRACT

The conoidean family Drilliidae Olsson, 1964 is a species-rich lineage of marine gastropods, showing a high degree of diversification in comparison to other families of Conoidea. Despite intensive molecular phylogenetic studies during the last decade that have led to notable rearrangements of conoidean systematics, the genus- and species-level taxonomy of Drilliidae has not thus far been affected and remains entirely based on shell features. In the current study we revisit species delimitation in a morphological cluster of species from the Indo-Pacific referred to as the Clavus canalicularis complex, using an integrative taxonomy approach. The species in the complex possess robust thick-walled shells typically over 15?mm in height with sculpture of prominent rounded nodules located at the whorl’s shoulder, sometimes sharp and squamiform, or producing long spines. We find that in addition to five known species, the complex comprises four new species. These are described as Clavus brianmayi n. sp. (New Caledonia), Clavus davidgilmouri n. sp. (the Philippines), Clavus andreolbrichi n. sp. (Vanuatu and New Ireland) and Clavus kirkhammetti n. sp. (Madagascar). Clavus exasperatus (Reeve, 1843), which was previously considered widely distributed in Indo-Pacific, is shown to be confined to the western Indian Ocean.     

Oogenesis in four species of Piscicola (Hirudinea, Rhynchobdellida)

Piscicola has a pair of elongated sac-shaped ovaries. Inside the ovaries are numerous small somatic cells and regularly spherical egg follicles. Each follicle is composed of three types of cells: many (average 30) germ cells (cystocytes) interconnected by intercellular bridges in clones (cysts), one intermediate cell, and three to five outer follicle cells (envelope cells). Each germ cell in a clone has one intercellular bridge connecting it to the central anucleate cytoplasmic mass, the cytophore. Each cluster of germ cells is completely embedded inside a single huge somatic follicle cell, the intermediate (interstitial) cell. The most spectacular feature of the intermediate cell is its development of a system of intracytoplasmic canals apparently formed of invaginations of its cell membrane. Initially the complex of germ cell cluster + intermediate cell is enclosed within an envelope composed of squamous cells. As oogenesis progresses the envelope cells gradually degenerate. All the germ cells that have terminated their mitotic divisions are of similar size and enter meiotic prophase, but one of the cystocytes promptly starts to grow faster and differentiates into the oocyte, whereas the remaining cystocytes withdraw from meiosis and become nurse cells (trophocytes). Numerous mitochondria, ER, and a vast amount of ribosomes are transferred from the trophocytes via the cytophore toward the oocyte. Eventually the oocyte ingests all the content of the cytophore, and the trophocytes degenerate. Little vitellogenesis takes place; the oocyte gathers nutrients in the form of small lipid droplets. At the end of oogenesis, an electron-dense fibrous vitelline envelope appears around the oocyte, among short microvilli. At the same time, electron-dense cortical granules occur in the oocyte cortical cytoplasm; at the end of oogenesis they are numerous, but after fertilization they disappear from the ooplasm. In the present article we point out many differences in the course of oogenesis in two related families of rhynchobdellids: piscicolids and glossiphoniids.     

不同蒿属植物对光强的适应性差异研究

对中国四种蒿属植物(毛莲蒿、蒙古蒿、牡蒿和灰苞蒿)的光合响应曲线进行了研究。结果表明:牡蒿具有高光饱点(411.0μmol·m-2·s-1)和最大光合速率(18.627μmol·m-2·s-1),以及较低的光补偿点(17.867μmol·m-2·s-1),对高光的适应能力最强;灰苞蒿的暗呼吸速率(0.353μmol·m-2·s-1)和表观量子效率(0.038)最低,说明该种对弱光的适应能力较差,且在弱光条件下只能维持较低的生长速率;灰苞蒿水分利用效率随光强的变化趋势与其他三种蒿属植物一致,但总体上维持在一个较高的水平,可能与其对干旱生境的适应有关。光合响应曲线各个拟合指标在种间呈现出了较大的变异,其中光补偿点(L cpμmol·m-2·s-1)和暗呼吸速率(R dayμmol·m-2·s-1)差异达到了显著水平。说明植物功能性状与植物对环境长期适应密切相关,并且这种适应性是稳定可遗传的。     

The life-cycles of four amphipod species in the Kattegat

Populations of four species of Gammaridae (Crustacea, Amphipoda) were sampled over 15 months in the south-western Kattegat at Sangstrup Klint (Denmark). Chaetogammarus marinus, C. stoerensis and Gammarus oceanicus had annual life-cycles, while G. salinus most likely had two generations per year. Mature C. marinus females were found from March to July, mature C. stoerensis females from March to June, mature G. oceanicus females from December to early June and mature G. salinus females from late November to late July. The theoretical maximum number of clutches were estimated at five for C. marinus , five plus for C. stoerensis , and six for G. oceanicus and both winter and summer reproducing G. salinus . Spring was the period of main recruitment in all populations, with additional recruitment during summer in G. salinus .
The geographical patterns of the reproductive strategies are discussed in relation to environmental factors and interspecific competition.     

Taxonomy of the Colocasiomyia gigantea species group (Diptera,Drosophilidae), with descriptions of four new species from Yunnan,China

Species of the genus Colocasiomyia de Meijere feed/breed on inflorescences/infructescences of the plants from the families Araceae, Arecaceae and Magnoliaceae. Although most of them utilize plants from the subfamily Aroideae of Araceae, three species of the recently established C. gigantea species group make use of plants of the subfamily Monsteroideae. We describe four new species of the gigantea group found from Yunnan, China: Colocasiomyia longifilamentata Li & Gao, sp. n., C. longivalva Li & Gao, sp. n., C. hailini Li & Gao, sp. n., and C. yini Li & Gao, sp. n. The species delimitation is proved in virtue of not only morphology but also DNA barcodes, i.e., sequences of the partial mitochondrial COI (cytochrome c oxidase subunit I) gene. Some nucleotide sites with fixed status in the alignment of the COI sequences (658 sites in length) are used as “pure” molecular diagnostic characters to delineate species in the gigantea group.     

Differences in penetration routes and establishment rates of four entomopathogenic nematode species into four white grub species

We compared the penetration of the entomopathogenic nematodes Steinernema scarabaei (AMK001 strain), S. glaseri (NC1 strain), Heterorhabditis zealandica (X1 strain), and H. bacteriophora (GPS11 strain) into third-instars of the scarabs Popillia japonica, Anomala orientalis, Cyclocephala borealis, and Rhizotrogus majalis. When larvae were exposed to nematodes for 6-72 h larval mortality and nematode establishment rate and occasionally speed of kill often showed the same pattern within nematode-white grub combinations. But no two nematodes or white grub species had the same pattern for these observations for all white grub or nematode species, respectively. Mortality, establishment, and speed of kill followed a similar pattern for H. zealandica, S. glaseri, and S. scarabaei, but there was no clear relationship for H. bacteriophora. Significant nematode establishment was only observed after at least 48 h exposure in most nematode-white grub combinations. Faster establishment was observed only for H. zealandica in A. orientalis and R. majalis (after 24 h) and for S. scarabaei in P. japonica and R. majalis (after 12 h). Nematode establishment after 72 h in the different scarab species was generally low for S. glaseri (<1.5%) and H. bacteriophora (<3%), higher for H. zealandica (2-5%), and the highest for S. scarabaei (1-14%). However, in another experiment establishment was generally higher after 96h exposure. Nematode penetration sites were determined by comparing nematode establishment in larvae with mouth, anus, mouth+anus, or none sealed with glue. The trends for each nematode species were very similar in the different white grub species. H. zealandica and H. bacteriophora showed excellent cuticular penetration ability but may also penetrate through mouth and/or anus. S. glaseri also penetrated through the cuticle but lower establishment in larvae with mouth or mouth+anus sealed suggested that the mouth is an important penetration site. S. scarabaei showed a preference for the mouth as a penetration site, but it showed some cuticular penetration ability and may also use the anus as a penetration site. The methodology used cannot exclude that cuticular penetration also included penetration through the spiracles. To fully understand the effect of nematode and white grub species on nematode virulence, future studies will have to compare host immune response to the penetrating IJs and the role of the symbiotic bacteria in these interactions.     

Redescription of four species of Mehdiella from Testudinidae, with a key to the species and discussion on the relationships among the species of this genus

Four species of the genus Mehdiella Seurat, 1918 are redescribed: M. cristata Petter, 1966 and M. stylosa dollfusi Petter, 1966, parasite of Pyxix arachnoides Bell, 1827 from Madagascar, M. s. stylosa (Thapar, 1925) and M. uncinata (Drasche, 1884), parasite of Testudo graeca Linneaus, 1758, Testudo hermanni Gmelin, 1789 and Testudo horsfieldii (Gray, 1844) from Palaearctic region. Light microscopy and scanning electron microscopy (SEM) studies revealed new informations on the morphology of these species. On the basis of this morphological study, the sub-species Mehdiella stylosa dollfusi and M. s. stylosa are raised to level of species. The position of Mehdiella cristata among the species of the genus Mehdiella and the relationships among the species of the genus Mehdiella are discussed. A key to the eight valid species Mehdiella is given.     

Lipids of four species of freshwater dinoflagellates

The steroidal derivatives, fatty acid alkyl esters and triacylglycerols have been identified in two cultured dinoflagellates, Woloszynskia coronata and Ceratium furcoides, and natural populations of two species, Peridinium lomnickii and P. cinctum. Within each species, the same sterol moieties occurred in free and esterified forms, but the species differed in the proportion of 4α-methyl and desmethyl sterols. Both groups occurred in the two Peridinium species, whereas W. coronata contained only 4α-methylsterols and C. furcoides, uniquely among dinoflagellates analysed to date, contained only desmethylsterols, although these were analogues of 4α-methylsterols present in the other species. 4α-Methyl steroidal ketones were present in P. lomnickii and W. coronata; cholest-4-en-3-one and 5α-cholestan-3-one were detected in C. furcoides, but no steroidal ketones were detected in P. cinctum. Methyl and ethyl esters of fatty acids (C₁₂C₁₈) were detected in three species, in P. cinctum the ethyl esters were dominant, while phytyl esters occurred only in the Peridinium spp. The molecular composition of triacylglycerols containing only saturated and monoenoic acyl groups was determined by GC-MS. Lower carbon number constituents from W. coronata contained a C₄ acyl group, previously found only in animal milk fats.     

Aminopeptidase profiles of four species of phytophthora

Phytophthora palmivora, P. cinnamomi, P. drechsleri, and P. cactorum were readily separated on the basis of the aminopeptidase substrate specificities of their mycelial suspensions. Variability among isolates of the same species was not significant with most substrates and isolates tested, regardless of source. Both qualitative and quantitative differences in enzyme activity were useful for species identification. Differentiation of these four species was possible with comparative reactions of l-alanyl-, l-arginyl-, l-benzoylarginyl, l-gamma-glutamyl-, l-glycyl-, l-hydroxyprolyl-, l-leucyl-, l-lysyl-, 4-methoxyleucyl-, l-prolyl-, and 4-methoxyalanyl-beta-naphthylamides. Variation in peptidase activity was usually detectable after 4 h of incubation, with increased activity sometimes manifest after 24 h of incubation. P. palmivora exhibited the lowest, and P. drechsleri exhibited the highest, overall peptidase activity. This fluorescent aminopeptidase profile procedure provides a relatively rapid method to supplement other taxonomic criteria for identification of these species of Phytophthora.