Different methods for the evaluation of species of the genus Mesaphorura (Collembola, Tullbergiinae)

Field studies and laboratory investigations based upon cultures, isoenzyme electrophoresis and RAPD-PCR were carried out to get a better understanding of the value of morphospecies within the genus Mesaphorura.Culturing of seven Mesaphorura species under constant as well as variable conditions provided a basis for evaluation of morphological characters, but did not yield any statistically supportable evidence that intraspecific variability reached interspecific delimitations.In enzyme tests, esterases gave the best results. The search for species-specific band patterns is, however, time and material consuming. DNA investigations using RAPD-PCR resulted in band patterns that appeared to be species specific. Nevertheless, these require further investigations.None of the studies carried out gave any conclusive evidence for invalidation of the morphologically defined species of the genus Mesaphorura.     

Mendeschilis a new genus of Microcoryphia (Insecta, Apterygota, Machilidae) from Spain

A new species and genus of Microcoryphia is described as a result of the detailed comparison of specimens from Italy and Spain which had been initially identified as Praemachilis excelsior. The new genus, named Mendeschilis has as its most important distinctive taxonomic characteristic the presence, in the male, of parameres in the VIII^th and IX^th urosternites, while Praemachilis (from Italy) has only one pair of parameres in the IX^th urosternite. Other anatomical characteristics which allow us to differentiate the new genus and the new species are described.     

Responses of co-occurring populations of Dendrobaena octaedra (Lumbricidae) and Cognettia sphagnetorum (Enchytraeidae) to soil pH, moisture and resource addition

Dendrobaena octaedra (Lumbricidae) and Cognettia sphagnetorum (Enchytraeidae) are the two most dominating soil invertebrates in terms of biomass in boreal coniferous forest soils. A microcosm experiment was set up in order to study the influence of pH, moisture and resource addition on D. octaedra and C. sphagnetorum when both species are simultaneously present. Two kinds of coniferous forest humus were used as substrate, pine stand humus (pH 4.2), and spruce stand humus (pH 4.6); in the third treatment the pine stand humus was adjusted with slaked lime (CaOH₂) to the same initial pH as the spruce stand humus. Each substrate was adjusted to water contents of 25%, 42.5% and 60% of WHC (referred to as ‘dry’, ‘moist’ and ‘wet’). In the second part of the experiment, spruce needle litter and birch leaf litter were separately added into the pine stand humus (‘moist’, unlimed) and compared with a control without litter. The microcosms were plastic jars with 75 g (d.m.) of humus, into which 4 specimens of D. octaedra and 70 specimens of C. sphagnetorum were added. D. octaedra showed the highest biomass and C. sphagnetorum the lowest biomass in the spruce stand humus with higher pH. Moisture did not affect earthworms, while C. sphagnetorum thrived best at the highest moisture. Addition of both kinds of litter increased the numbers and biomass of D. octaedra, while on C. sphagnetorum resource addition had little effect. The results help to explain the abundance of these two species in coniferous forests differing in soil acidity, moisture and fertility.     

Life cycle traits of the parthenogenetic earthworm Octolasion cyaneum (Savigny, 1826)

This laboratory-based study provides baseline life cycle data for the obligatory parthenogenetic earthworm Octolasion cyaneum. Singleton and twin hatchlings were cultured individually with biomass, survival and reproductive condition recorded at 4-weekly intervals during a complete year. After maturation, cocoon production, masses and incubation time were also recorded along with viability and number of hatchlings per cocoon. Individual mean mass of singletons was significantly (P < 0.05) greater than twins at the outset (0.042 and 0.025 g respectively) and remained so until week 52 (2.22 and 1.96 g respectively). Singletons matured more rapidly than twins (24 vs. 32 weeks respectively) and produced more cocoons than twins (3.2 and 2.2 coc worm⁻¹ (4 weeks)⁻¹ respectively). Approximately 20% of all viable cocoons produced twins. Singleton hatchlings weighed significantly (P < 0.05) more than twin hatchlings (0.032 and 0.018 g respectively) but there was no significant difference (P > 0.05) between mean masses of singleton (mean masses 0.033 and 0.032 g) or twin (0.017 and 0.018 g) hatchlings produced by singleton and twin parents. The likelihood that a cocoon contained twins or a singleton was not influenced by the singleton/twin status of the parent. There was no significant difference (P > 0.05) in the incubation times of cocoons produced by singletons and twins (129 and 128 days respectively).     

Addition of hydrogels to soil for prolonging the survival of Pinus halepensis seedlings subjected to drought

The effect of an amendment of a sandy soil with superabsorbent hydrogels (Stockosorb K 400, a highly cross-linked polyacrylamide with about 40% of the amide group hydrolysed to carboxylic groups) on the survival of Pinus halepensis seedlings during water stress was studied, with the following concentrations added to the soils: 0.04%, 0.08%, 0.12%, 0.20%, and 0.40%. The water retention of the soil increased exponentially with increasing additions of hydrogel to the soil. The highest concentration used changed the water retention capacity and its change in water potential with regard to its water content from a typical sand to a loam or even silty clay. During desiccation under controlled conditions, the seedlings treated with 0.4% hydrogel survived twice as long in the soils amended with 0.4% hydrogel as in the control soils. During the drought, the seedlings exhibited a pronounced growth both of the shoot and the roots, which was about three-fold higher than the one of the plants in the control soils. The data indicate that an amendment of soils with this type of hydrogels at 0.4% (w/w) will greatly enhance the drought tolerance of the seedlings growing on this substrate. A comparison between the reaction of the plants in the hydrogel amended soils and the pF-curve measured with the plate test revealed that less water was actually available for the plants, as could be expected from the pF-curves.     

Correlates of abundance and breeding success in the globally threatened Hinde's babbler (Turdoides hindei) and its congener, northern pied babbler (T. hypoleucus)

We investigated the relationship between habitat quality, abundance, group size and breeding success in the threatened Kenyan endemic Hinde's babbler (Turdoides hindei; Family Timaliidae), a co-operative breeder mainly associated with riverine thickets in cultivated areas. At two intensively cultivated sites, significantly more Hinde's babbler groups occurred in areas retaining at least 3% thicket cover, while breeding outcome improved where cover exceeded 9%. Despite previous concerns over low breeding success, the percentage of young birds present (17%, n=424 birds aged) was similar to that of a sympatric congener, the northern pied babbler (T. hypoleucus) (12%, n=162), and comparable with that of two other African congeners. Although breeding outcome was positively correlated with adult group size, there was no evidence that larger groups monopolised more favourable habitat or defended larger territories. Group density showed a positive, non-linear relationship with adjacent cover, levelling out where this exceeded 15-20%. Our findings suggest that even a modest increase in thicket cover may significantly raise the density and productivity of Hinde's babblers at these sites.     

New sources of resistance to race Ro1 of the Golden nematode (Globodera rostochiensis Woll.) among reputed duplicate germplasm accessions of Solanum tuberosum L. subsp. andigena (Juz. et Buk.) Hawkes in the VIR (Russian) and US Potato Genebanks

Cultivated Solanum tuberosum L. subsp. andigena is well known as a rich source of valuable traits for potato breeding, especially for resistance to diseases and pests. The golden potato cyst nematode, Globodera rostochiensis Woll., is considered to be one of todays most serious hindrances to potato production in Europe and North America. Thus, the breeding of new cultivars that have resistance to PCN is of great importance. The USPG (USA) and VIR (Russian) potato genebanks, as well as others, maintain many samples of primitive cultivated and wild potato species originating from Latin America. Many of these samples are assumed to be genetically duplicated because the material in both genebanks came from the same original source. A joint investigation of new genotypes of subsp. andigena forms resistant to potato cyst nematode (PCN) was carried out on samples of subsp. andigena at VIR with reputed duplicate samples at USPG. After careful screening, 14 samples which possessed resistance to PCN were identified. A high level of this resistance was transmitted to sexual progeny at a high frequency for all of the selections. Eleven of the accessions found to be resistant have reputed duplicates in USPG that were not previously known to be resistant. Thus, this research not only broadens the choice of parents available for resistance breeding, but identifies model materials for future research to test the parity of PCN resistance among reputed duplicate samples in the two genebanks.     

Genetic variation in a subterranean arthropod (Folsomia candida) as a method to identify low-permeability barriers in an aquifer

Folsomia candida (order Collembola), a common soil arthropod, has recently been described living in a shallow (2.5–5.7 m below surface), unconsolidated aquifer in southwestern Michigan. F. candida was haplotyped from 14 wells using inter-simple sequence repeats (ISSRs) markers, and genetic variation in F. candida was used as a bioindicator to identify pore scale to mesoscale migration barriers in the aquifer. With one exception, individual haplotypes were only found in single wells. A significant relationship was identified between interpopulation genetic differentiation and geographic distance, and F. candida exhibits genetic population structuring over a very fine geographic scale (0.65 km²). Monmonier's algorithm was used to identify two most likely subsurface barriers to migration. Hypothesized barriers divided the F. candida populations into three genetically distinct groups, with two groups separated by only 15 m. These groupings are not dependent on groundwater flow direction, and are supported by a minimum spanning network and AMOVA analysis. Because F. candida movement is limited by pore size, these barriers identify local areas of low permeability in the aquifer material. The study suggests that F. candida may serve an important role in identifying geological characteristics and patterns in aquifers that may be difficult to evaluate by other means.     

Seasonal distribution of Xenylla brevispina (Collembola) in the canopy and soil habitat of a Cryptomeria japonica plantation

We investigated the life cycle and habitat use of an arboreal collembolan species, Xenylla brevispina, in the canopy and soil of a conifer (Cryptomeria japonica D. Don) plantation. The adaptive significance of migration between arboreal and soil habitats in the maintenance of its population in relation to the vertical structure of the forest is discussed. We sampled dead branches with foliage in the canopy (canopy litter) and on the forest-floor (soil litter). X. brevispina had one generation a year throughout the 3 years of the study. The mean densities of X. brevispina were similar in the canopy litter (0.06 to 14.57 g⁻¹ dry weight) and the soil litter (0.44 to 18.99 g⁻¹ dry weight). Seasonal patterns of density and relative abundance indicate that individuals of X. brevispina in the canopy were closely associated with those in the soil. These results suggest that vertical migration between the canopy and the soil might be a strategy allowing X. brevispina to be a predominant collembolan species in this forest.     

Oleaster (var. sylvestris) and subsp. cuspidata are suitable genetic resources for improvement of the olive (Olea europaea subsp. europaea var. europaea)

The olive belongs to Olea, a complex genus and to a species with six subspecies. Subsp. europaea includes both the cultivated olive and the oleaster, the wild ancestor of the olive. Little is known on the phenotype of fruits from subsp. cuspidata. We aimed to compare europaea and cuspidata trees for oil content and composition and to verify whether natural hybrids may exist between the two subspecies. Specimens were from Kenya and putative natural hybrids between cuspidata and europaea were from Stellenbosch (South Africa). Cultivar and oleaster trees were sampled in France (continental and Corsica), Italy (Continental and Sardinia) and Tunisia. We have examined the fruit (drupe) structure between subsp. cuspidata and europaea and extracted oil from the pulp, seed and total drupe. Comparison for oil content was made between the cultivated olive and the oleaster and some cuspidata trees from Kenya. A few of cuspidata individuals from Botanical gardens do not enable phenotyping for oil content and composition. Oil composition analyses were performed for the main fatty acids to compare the three taxa. We used microsatellite markers at 11 loci to compute genetic distances between cuspidata, oleaster and cultivar trees and to reveal eventual hybrids. The SSR polymorphisms were huge between the two subspecies and they revealed that putative hybrids were true hybrids sampled around olive orchards. The whole comparison of oil content shows that olive cultivars display higher oil content than the subsp. cuspidata and that the oleaster trees are intermediate, whereas for oil composition of the drupe, cuspidata from Kenya shows less oleic acid than europaea. However, the cuspidata trees show seed oil composition similarities with the other two taxa. The discussion deals with possible reasons to explain the differences and of the possible uses of these taxa for breeding both the olive and brown olive. H. Hannachi and H. Sommerlatte have equal contribution in the article.     

Geographical barriers and ecological gradients: Geographical distribution of the subspecies and morphotypes of Deutonura deficiens Deharveng, 1979 (Collembola: Neanuridae)

This work explores the links between ecogeographical barriers and clines, and the boundaries of infraspecific biological entities. The distribution of the three subspecies and eight morphotypes of the Neanurinae Deutonura deficiens (Collembola) are mapped and commented based on 570 records. The species inhabits a wide range of forest habitats from the north of Portugal to southeastern France. The subspecies and morphotypes constitute homogeneous geographic sets arranged as a mosaic of closely related forms. A few overlapping zones between subspecies or morphotypes have been detected, some of them having the character of hybrid zones; on the whole however, overlap is small or rare and allopatry or parapatry is the general pattern. Current range boundaries of subspecies and morphotypes were found to be usually not determined by major hydrographical and topographical barriers, with the noticeable exception of the Rhône River. At subspecies level, the morphological cline of increasing tuberculization correlated to the bioclimatic gradient from Mediterranean to Atlantic climates, already recorded by Deharveng (1984. Polymorphisme et polytypisme morphologiques chez quelques Neanurinae européens. Rev. Ecol. Biol. Sol. 21, 533–562), is confirmed on the present data set. Conversely, ecological boundaries, known to constrain species distribution in many living groups of the region, do not fit the contact zones between the different morphotypes of the three subspecies of D. deficiens. The eight recognized forms appear to be at different degrees of reproductive isolation, illustrating active speciation process possibly inherited from recent ecogeographical events. A more detailed sampling on contact zones and a robust phylogenetic hypothesis are needed at this stage for progressing in our understanding of this complex pattern.     

Population structure and movements of a threatened butterfly (Lopinga achine) in a fragmented landscape in Sweden

The red-listed butterfly Lopinga achine was studied by mark-recapture methods in southern Sweden for three seasons. We examined movement within and between populations and egg production in relation to age. The majority of the movements were small with mean movements between recaptures of 45-54 m for males and 94-116 m for females. There were few movements between sites, 20 of 996 recaptured males moved and 36 of 391 recaptured females, even though the distance to other sites was in many cases <100 m. The distance moved and the number of females moving between sites increased with increasing age. On average, a female that moves does so after laying two-thirds of its eggs in its natal site. It is therefore important to take account of the proportion of reproductive effort involved in dispersal when estimating colonisation ability. The males did not move more with increasing age. Female behaviour can be seen as a “spread-the-risk” strategy, an adaptation to the successional habitat of L. achine, whose natal site sooner or later will deteriorate. Butterflies like L. achine living in successional habitats may exhibit mobility that is intermediate between butterflies living in ephemeral habitats (very mobile) and in long-lived habitats (sedentary).     

Habitat and food choice of the critically endangered cao vit gibbon (Nomascus nasutus) in China: Implications for conservation

Knowledge of habitat and feeding ecology is essential for developing an effective conservation management plan for threatened primates. Despite having been rediscovered nearly a decade ago, very little is known of the critically endangered cao vit gibbon (Nomascus nasutus) or its habitat. We analysed forest cover, made direct observations and conducted interviews of local elders to better understand forest changes and to determine the forest characters and species important to the survival of the gibbon. Interviews indicated human-induced forest resource exploitation focused on species-specific and larger trees most easily accessed. Gibbon forest habitat comprised four primary forest types. The mean canopy height over the whole site was 10.52 m. Gibbons consumed 81, or nearly half of the tree and liana species recorded in the site; however, only 19 species provide 77.8% of the diet. Six of the 19 food species were logged for different reasons throughout the history of the site. We conclude that effective conservation management of primates with highly limited distributions, focused dietary needs, and in degraded ecosystems will require active forest restoration, such as planting important food species in degraded sites.     

Uptake and toxicity of copper and zinc for the African earthworm,Eudrilus eugeniae (Oligochaeta)

Growth rate change in earthworms is considered to be a suitable endpoint when determining sublethal effects. In this study we evaluated growth and maturation in the vermicomposting earthworm speciesEudrilus eugeniae as marker of sublethal toxicity of copper and zinc. We also compared routes of uptake. Apart from exposing worms experimentally for 73 days to contaminated food, a series of contact filter paper tests was also performed to determine LD₅₀ for copper and zinc. Both copper and zinc at sublethal concentrations affected growth and maturation in worms exposed to contaminated food. These worms had a copper content of 34.5 g g^–1 after 73 days and a zinc content of 184.9 g g^–1, showing a differential uptake. Copper was more toxic than zinc. Also in the contact test worms did take up more zinc than copper and the LD₅₀ (48 h) for copper was 0.011 mg cm^–2 and for zinc 0.066 mg cm^–2, which translated to body burdens of 6 g g^–1 for copper and 131 g g^–1 for zinc. Indications were that a regulatory mechanism existed for both metals. Both metals were taken up through the body wall at a relatively fast rate. This study indicated that the skin was the major route of metal uptake. This study also showed a poor relation between the two types of tests for purposes of evaluating lethality of zinc and copper.     

Distribution of Pill Millipedes (Arthrosphaera) and Associated Soil Fauna in the Western Ghats and West Coast of India

Seven sampling sites in each of three biomes (Western Ghats, foothills of Western Ghats and west coast) of south-western India were investigated to study the distribution, abundance and ecology of pill millipedes (Arthrosphaera)and associated fauna in relation to edaphic features. Abundance and biomass of Arthrosphaera and other millipedes were the highest in Western Ghats, while earthworms were in foothills. Arthrosphaera magna and Arthrosphaera spp. were common in Western Ghats and foothills respectively, while no Arthrosphaera were found in the west coast. None of the sampling sites consisted of more than one species of Arthrosphaera. Biomass of Arthrosphaera, other millipedes and earthworms significantly differed in Western Ghats (P =9.48 × 10⁻⁷) and foothills (P =1.35 × 10⁻⁸), as did the biomass of species of Arthrosphaera (P =2.76 × 10⁻⁷) between Western Ghats and foothills. Correlation analysis revealed that biomass of Arthrosphaera was significantly (P =0.01, r =0.45) correlated with soil organic carbon rather than other edaphic features (pH, phosphate, calcium and magnesium). Distribution pattern, abundance, biomass and ecology of Arthrosphaera of Western Ghats in relation to soil qualities were compared with millipedes of other regions of the world.     

Population genetic structure of Orchesella cincta (Collembola; Hexapoda) in NW Europe, as revealed by microsatellite markers

We studied genetic variation and population differentiation in the springtail Orchesella cincta L. An earlier approach, using allozymes, revealed extremely low variation among and within populations from NW Europe. Microsatellite marker analysis showed higher genetic variation than allozymes, and agreed with the previously reported low population differentiation in the species. Analysis of molecular variance showed that genetic variation within populations amounted to 96.5% of the total variation, whereas the remaining 3.5% is accounted for by population differentiation. Population differentiation, as described by microsatellite markers and with the exception of one population, can be explained by an isolation by distance. Although the microsatellites are short, viz. only up to 12 repeat units, they appear to be useful tools in revealing population genetic structures in O. cincta.     

Abundance of Frankia from Gymnostoma spp. in the rhizosphere of Alphitonia neocaledonica, a non-nodulated Rhamnaceae endemicto New Caledonia

The capacity of different soils of New Caledonia to induce nodulation in Gymnostoma poissonianum was studied. The soils were sampled under five Gymnostoma species, Alphitonia neocaledonica (a non-nodulated endemic Rhamnaceae) and Pinus caribea (an introduced species) growing in various ecological conditions. Using G. poissonianum as trap-host, we observed a higher abundance of Frankia from Gymnostoma spp. in the rhizosphere of A. neocaledonica as compared with bare soils and P. caribea rhizosphere. The nodulating capacity of A. neocaledonica rhizosphere was almost similar to that of the five Gymnostoma species (symbiotic host) studied in the same stations. In comparison, bare soils or rhizosphere of P. caribea had poor nodulating capacities. We isolated fourteen Frankia strains from nodules of G. poissonianum after baiting with the rhizospheric soils of five Gymnostoma and A. neocaledonica. Using the PCR/RFLP method, we confirmed the similarity with those already described. Frankia was abundant in the rhizosphere of A. neocaledonica in all the sites studied. One explanation could be a positive tropism of Frankia towards species belonging to families having nodulated species, which is the case of A. neocaledonica endemic in New Caledonia. We can suppose that the non-nodulated plants belonging to these families can excrete some chemical substances able to attract Frankia and to induce its proliferation.     

Effects of temperature regime on the respiratory activity of developmental stages of Lumbricus rubellus (Lumbricidae)

Rates of carbon dioxide production of cocoons, juveniles and matures of Lumbricus rubellus were measured at five constant (2°C, 5°C, 10°C, 15°C, 20°C) and three diurnally fluctuating temperature regimes (0–10°C, 5–15°C, 10–20°C) covering the whole range of temperature conditions experienced by this species in forests in Central Germany. Respiration rates of developmental stages significantly increased with temperature both under constant and fluctuating regimes. Overall, at constant temperature regimes Q₁₀ values for cocoons, juvenile and mature earthworms were 1.6, 2.7 and 2.0, respectively. At fluctuating temperature regimes Q₁₀ values were generally higher with 2.4, 3.6 and 3.5 for cocoons, juvenile and mature earthworms, respectively. At the same mean temperature respiration rates at fluctuating regimes exceeded those at constant regimes in all developmental stages.     

Demography of Asian elephants (Elephas maximus) at Uda Walawe National Park, Sri Lanka based on identified individuals

We provide estimates of population size and other demographic variables for individually-identified Asian elephants (Elephas maximus) in Uda Walawe National Park (UWNP), Sri Lanka based on systematic year-round observations. Two hundred and eighty-six adult females and 241 adult males were identified, of which four adults (2% of males) had tusks. Sightings-based demographic models showed seasonal immigration and emigration from the study area. The total population, including non-adults, was between 804 and 1160 individuals. Density ranged from 102 to 116 adult females per 100 km² and remains at this level throughout the year. This large, un-fragmented population of Asian elephants should be of high conservation priority. We find that estimates of survivorship and migration rates should be based on long sampling intervals when possible, but estimates of density and population size can still be made when observations are constrained to shorter intervals, if spatial data are available. We offer suggestions to guide census design for other elephant populations or cryptic species. We urge that other locations be systematically surveyed as well using photographic identification.