Barcoding Eophila crodabepis sp. nov. (Annelida,Oligochaeta, Lumbricidae), a Large Stripy Earthworm from Alpine Foothills of Northeastern Italy Similar to Eophila tellinii (Rosa, 1888)

A new Italian earthworm morphologically close to the similarly large and anecic Eophila tellinii (Rosa, 1888) is described. Distribution of Eophila crodabepis sp. nov. extends over 750 km² from East to West on the Asiago Plateau and Vittorio Veneto Hills, from North to South on mounts Belluno Prealps (Praderadego and Cesen), Asiago, Grappa and onto the Montello foothills. This range abuts that of Eophila tellinii in northern Friuli Venezia Giulia region. Known localities of both E. tellinii and E.crodabepis sp. nov. are mapped. mtDNA barcoding definitively separates the new western species from classical Eophila tellinii (Rosa, 1888).     

Incidence of Entomophthora sp. and other natural control agents in populations of Pseudoplusia includens and Trichoplusia ni

A species of Entomophthora was observed as a mortality factor in populations of Pseudoplusia includens and Trichoplusia ni in cotton and soybean fields throughout Alabama. Resting spores appear identical to those of Tarichium gammae. The incidence of this fungus in host populations, as well as other disease agents and parasites, was determined from larval samples collected throughout the State. Entomophthora infected 8% of all loopers collected on cotton as compared to 35% on soybeans. T. ni nuclear polyhedrosis virus infected 41% of all loopers collected from cotton but no mortality attributable to virus was found in loopers collected on soybeans, which were predominantly P. includens.Studies in 1969 and 1970 on the incidence of Entomophthora sp. in a population of P. includens infesting soybeans in central Alabama have shown it to infect between 50 and 95% of all individuals present from early August through mid-September, the period of densest abundance of the caterpillars. Spicaria sp. was also present during August and September but did not contribute significantly to reduction in population levels until late in the season. Parasites accounted for less than 1% of all mortality in each year and predator populations were very small during the periods of observation.     

Cryptic microsporidian parasites differentially affect invasive and native Artemia spp.

We investigated the host specificity of two cryptic microsporidian species (Anostracospora rigaudi and Enterocytospora artemiae) infecting invasive (Artemia franciscana) and native (Artemia parthenogenetica) hosts in sympatry. Anostracospora rigaudi was on average four times more prevalent in the native host, whereas E. artemiae was three times more prevalent in the invasive host. Infection with An. rigaudi strongly reduced female reproduction in both host species, whereas infection with E. artemiae had weaker effects on female reproduction. We contrasted microsporidian prevalence in native A. franciscana populations (New World) and in both invaded and non-invaded Artemia populations (Old World). At a community level, microsporidian prevalence was twice as high in native compared with invasive hosts, due to the contrasting host-specificity of An. rigaudi and E. artemiae. At a higher biogeographical level, microsporidian prevalence in A. franciscana did not differ between the invaded populations and the native populations used for the introduction. Although E. artemiae was the only species found both in New and Old World populations, no evidence of its co-introduction with the invasive host was found in our experimental and phylogeographic tests. These results suggest that the success of A. franciscana invasion is probably due to a lower susceptibility to virulent microsporidian parasites rather than to decreased microsporidian prevalence compared with A. parthenogenetica or to lower microsporidian virulence in introduced areas.     

Widespread horizontal transfer of the cerato-ulmin gene between Ophiostoma novo-ulmi and Geosmithia species

Previous work had shown that a sequence homologous to the gene encoding class II hydrophobin cerato-ulmin from the fungus Ophiostoma novo-ulmi, the causal agent of Dutch Elm Disease (DED), was present in a strain of the unrelated species Geosmithia species 5 (Ascomycota: Hypocreales) isolated from Ulmus minor affected by DED. As both fungi occupy the same habitat, even if different ecological niches, the occurrence of horizontal gene transfer was proposed. In the present work we have analysed for the presence of the cerato-ulmin gene 70 Geosmithia strains representing 29 species, isolated from different host plants and geographic locations. The gene was found in 52.1 % of the strains derived from elm trees, while none of those isolated from nonelms possessed it. The expression of the gene in Geosmithia was also assessed by real time PCR in different growth conditions (liquid culture, solid culture, elm sawdust, dual culture with O. novo-ulmi), and was found to be extremely low in all conditions tested. On the basis of these results we propose that the cerato-ulmin gene is not functional in Geosmithia, but can be considered instead a marker of more extensive transfers of genetic material as shown in other fungi.     

Do hairworms (Nematomorpha) manipulate the water seeking behaviour of their terrestrial hosts?

Several anecdotal reports in the literature have suggested that insects parasitized by hairworms (Nematomorpha) commit `suicide' by jumping into an aquatic environment needed by an adult worm for the continuation of its life cycle. Based on 2 years of observations at a swimming pool in open air, we saw this aberrant behaviour in nine insect species followed by the emergence of hairworms. We conducted field and laboratory experiments in order to compare the behaviour of infected and uninfected individuals of the cricket Nemobius sylvestris. The results clearly indicate that crickets infected by the nematomorph Paragordius tricuspidatus are more likely to jump into water than uninfected ones. The idea that this manipulation involved water detection from long distances by infected insects is not supported. Instead, our observations suggest that infected insects may first display an erratic behaviour which brings them sooner or later close to a stream and then a behavioural change that makes them enter the water.     

Hebeloma species associated with Cistus

The genus Hebeloma has a number of species highly specific to Cistus and others that occur with several host genera. This paper discusses the species of Hebeloma that appear to be ectomycorrhizal with Cistus, judging from their occurrence when Cistus is the only available host. The previously unknown species H. plesiocistum spec. nov. is described. We also provide a key to the known Hebeloma associates of Cistus. Molecular analyses based on ITS sequence data further illustrate the distinctness of the newly described species and difficulties in the species delimitation with view to H. erumpens. Specific associations with Cistus may have evolved more than once within the genus Hebeloma.     

Pollen morphology of Polylepis boyacensis cuatrecasas, Acaena cylindristachya ruiz et pavon and Acaena elongata L. (Rosaceae) and its application to fossil material

The pollenmorphology of recent pollen grains of the species of Polylepis and Acaena (Rosaceae) occurring in the Colombian Cordillera Oriental is described on the basis of light microscopical and scanning electron microscopical study.The results were found to be applicable to the determination of fossil material from lake sediments of last glacial age of the same area.     

Occurrence and accumulation of viruses of Trichoplusia ni in treated field plots

Concentrations of the nuclear-polyhedrous virus (T. ni NPV) and the granulosis virus (T. ni GV) of the cabbage looper, Trichoplusia ni, in soil and on foliage were monitored up to 4 years after treatment.A single application of T. ni NPV to soil in August or 5 foliar applications of the virus at 10-day intervals in August and early September maintained substantial concentrations of the virus on foliage and high concentrations of the virus accumulated in soil. With development of natural epizootics of the virus disease in populations of the host larvae in September and October, substantial concentrations of the virus accumulated in soil and on foliage in nontreated plots, eventually becoming equal in amount with the virus in virus-treated plots. The virus accumulated more slowly in plots treated with chemical insecticides or Bacillus thuringiensis because few host larvae survived to support late-season epizootics of the disease. Small quantities of T. ni NPV were detected in heads of cabbage harvested from the plots in October.Long-term studies in which nontreated plots and plots treated with T. ni NPV or T. ni GV were replanted for up to 4 years after treatment showed that concentrations of T. ni NPV in surface soil remained constant during the winter but were reduced by dilution during cultivation preparatory to planting in the spring. T. ni NPV accumulated during the late summer and autumn with development of epizootics of the disease in populations of host larvae. Increased concentrations of the virus in soil coincided with increased concentrations on leaves in each year. T. ni GV did not persist on leaves or in soil following application and only small amounts were found 2 years after application.T. ni NPV disease was prevalent in September and October in populations of host larvae in plots in which substantial residues of the virus were found. These epizootics contributed substantially to late-season control of the looper after completion of spraying.     

The identity of Tetracyclus constrictus (Bacillariophyceae) and a description of Tetracyclusbradburyii, a new miocene species

The siliceous valves from species of Tetracyclus (Bacillariophyceae) have variable but characteristic shapes. In this paper, species characterised by having valves with a central constriction are discussed. This distinctive shape occurs during only a period of its lifecycle. Tetracyclus constrictus and Tetracyclus celatom have been applied to fossil specimens occurring in deposits from the west coast of the USA and the east coast of Russia. Do these names apply to two closely related species or are they one and the same taxon? Two further species, Tetracyclus javanicus and Tetracyclus peragalli, have been involved in the identity of T. constrictus–T. celatom. T. constrictus M. Peragallo is the correct name and author for specimens of the extinct Miocene, circum-Pacific (or northern) fossil species with valves panduriform with rounded poles; T. javanicus refers to a species found living on Java only; fossil specimens usually referred to T. javanicus (Java) belong to a new taxon, Tetracyclus bradburyii (USA); T. peragalli is an extinct Miocene fossil, with a northern hemisphere distribution; small (≤10 μm) circular/elliptical fossil specimens, found alongside other specimens, are difficult (if not impossible) to determine to species level.     

高榕榕果内Eupristina属两种榕小蜂的遗传进化关系

对生长在福州地区的高榕进行长期追踪观察,发现高榕榕果内仅生活着Eupristina altissima和Eupristina sp.榕小蜂,前者为高榕的传粉小蜂,后者无传粉行为,两者雌蜂之间在体色、触角、花粉袋和花粉刷等部位存在细微的差异,而两者雄蜂之间无形态差异。通过克隆福建地区5个样地的高榕榕果内收集到的E. altissima和Eupristina sp.榕小蜂,以及细叶榕的传粉小蜂Eupristina verticillata(外群)的Cytb及COI基因,并进行碱基组成及遗传距离分析,用邻接法构建系统发育树,分析两榕小蜂群体之间的遗传进化关系,结果显示:(1)榕小蜂COI及Cytb序列碱基组成中A+T的含量(Cytb序列中A+T=75.3%,COI序列中A+T=75.5%)显著高于G+C,符合膜翅目昆虫线粒体基因碱基组成特征。(2)对两群体小蜂进行遗传距离分析显示,Cytb序列中E. altissima和Eupristina sp. 群体内各样本之间的平均遗传距离分别为0.0092和0.0030,而E. altissima与Eupristina sp. 群体间的平均距离为0.1588;COI序列中E. altissima 与Eupristina sp. 群体内各样本之间的平均遗传距离分别为0.0065和0.0205,而二者群体间的平均遗传距离为0.1043,表明两者群体间的遗传距离明显大于各自群体内各样本间的遗传距离。统计GenBank中下载的6个属34种榕小蜂Cytb序列的种间遗传距离为0.0811-0.1723,6个属28种榕小蜂COI序列的种间遗传距离为0.0939-0.1986。由此认为E. altissima和Eupristina sp.之间的遗传距离差异已经达到了种间水平,即E. altissima与Eupristina sp.为两个不同的种。(3)在形态上,两种小蜂的雌蜂之间有微小差异,而二者雄蜂之间无差异,但Cytb与COI序列分析结果一致表明:E. altissima与Eupristina sp.雄蜂之间,以及二者雌蜂之间的遗传距离均差异显著,表明形态变异滞后于基因变异。雌蜂在表型上进化快于雄蜂,可能是由于雌蜂羽化后从榕果出飞,受到外界环境因素的影响较大,且两种雌蜂在传粉功能上存在差异,故二者之间的形态差异较大,而雄蜂寿命短,又终生生活在黑暗封闭、环境变化相对恒定的榕果内,两种雄蜂在行为上不存在差异,故二者表型变异较为缓慢。E. altissima和Eupristina sp.小蜂对宿主的专一性不强,在榕-蜂协同进化过程中,可能发生过宿主转移事件。     

Characterization of the mating-type genes in Leptographium procerum and Leptographium profanum

Leptographium procerum and the closely related species Leptographium profanum, are ascomycetes associated with root-infesting beetles on pines and hardwood trees, respectively. Both species occur in North America where they are apparently native. L. procerum has also been found in Europe, China New Zealand, and South Africa where it has most probably been introduced. As is true for many other Leptographium species, sexual states have never been observed in L. procerum or L. profanum. The objectives of this study were to clone and characterize the mating type loci of these fungi, and to develop markers to determine the mating types of individual isolates. To achieve this, a partial sequence of MAT1-2-1 was amplified using degenerate primers targeting the high mobility group (HMG) sequence. A complete MAT1-2 idiomorph of L. profanum was subsequently obtained by screening a genomic library using the HMG sequence as a probe. Long range PCR was used to amplify the complete MAT1-1 idiomorph of L. profanum and both the MAT1-1 and MAT1-2 idiomorphs of L. procerum. Characterization of the MAT idiomorphs suggests that the MAT genes are fully functional and that individuals of both these species are self-sterile in nature with a heterothallic mating system. Mating type markers were developed and tested on a population of L. procerum isolates from the USA, the assumed center of origin for this species. The results suggest that cryptic sexual reproduction is occurring or has recently taken place within this population.     

Are the microcyclic rust species Puccinia melampodii and Puccinia xanthii conspecific?

The taxonomic relationship between two microcyclic rust species, Puccinia melampodii and Puccinia xanthii, recorded from a number of Asteraceae hosts, was explored by comparing teliospore morphology, host specificity and sequence data. Teliospore morphology varied between and within individual rust accessions but, in general, teliospores of P. xanthii were larger than those of P. melampodii. Field observations and cross-inoculation greenhouse studies showed that P. melampodii accessions were highly specific to their original host species and unable to establish compatible interactions with related Asteraceae species. Though small amounts of genetic variation were detected between P. melampodii and P. xanthii accessions, the ITS and TEF phylogenetic analyses comprising several other rust species grouped these accessions within a well supported clade. Our data indicate that despite differences between P. xanthii and P. melampodii accessions these rusts cannot readily be separated at the species level, supporting earlier taxonomic conclusions and the recent proposal to group them into a morphospecies. Based on host-specificity data, the name Puccinia xanthii var. parthenii-hysterophorae is proposed to accommodate all Mesoamerican records of P. melampodii associated with the host Parthenium hysterophorus.     

Effects of the epibiotic heterotrich ciliate Mirofolliculina limnoriae and of moulting on faecal pellet production by the wood-boring isopods, Limnoria tripunctata and Limnoria quadripunctata

The heterotrich ciliate Mirofolliculina limnoriae occurs in an obligate association with wood-boring species of the isopod Limnoria. It attaches to the dorsal surface of the limnoriid pleotelson. Folliculinid-bearing populations of Limnoria tripunctata from the Ria Formosa, Portugal, and of Limnoria quadripunctata from Portsmouth, UK, were sampled. Up to four folliculinids were found on one individual of L. quadripunctata and up to twelve on L. tripunctata. There was no evidence that folliculinid load increased with host size. The nature of the epibiont/basibiont relationship was examined by observing animals with and without epibionts, kept individually with small sticks of wood in cell culture wells over periods of up to 15 days. Faecal pellet production and moulting were recorded. In both host species, feeding rate as measured by faecal pellet production was significantly lower in animals bearing folliculinids. Feeding rate also diminished with the onset of moulting, but returned to the original rate within a week after moulting. The estimated intermoult period for the population of L. tripunctata examined was about 25 days and for L. quadripunctata was about 32 days. However, the proportion of individuals moulting over the period of observation declined with increasing size in L. tripunctata, suggesting increasing length of intermoult period with age. As the host faces toward the blind end of its tunnel and ventilates the burrow with its pleopods, the folliculinids are well placed to intercept particulate food in the incoming water stream. There are no clear advantages for the host in the association, but the suppression of feeding and the potential of the folliculinids to hinder swimming during dispersal migrations indicate that the association should be viewed as ectoparasitism rather than mutualism or commensalism.     

Allelopathic activity of Elodea canadensis and Elodea nuttallii against epiphytes and phytoplankton

Elodea nuttallii and Elodea canadensis have both been introduced from North America to Europe. They are now common in many water bodies where they often form dominating stands. It was suggested that negative relationships between Elodea and phytoplankton or epiphytic covers exist, probably due to the release of growth inhibiting allelochemicals. This would be an effective strategy to avoid light limitation caused by algae and cyanobacteria. We investigated the allelopathic potential of both E. nuttallii and E. canadensis against different photoautotrophs, focussing on epiphytic algae and cyanobacteria isolated from different submersed macrophytes and culture strains. Methanolic extracts of both species inhibited the growth of most of these organisms. Only a culture strain of Scenedesmus brevispina was stimulated. Further separation of extracts yielded several active fractions, indicating that hydrophilic and slightly lipophilic compounds were responsible for growth reduction. At least some of the activity seems to be related to phenolic substances, but flavonoids in these species are inactive. Since growth declined also in a moderately lipophilic fraction of culture filtrate of E. nuttallii, we assume that active compounds were exuded in the water. Allelopathy might thus be relevant in situ and suppress cyanobacteria and algae. We furthermore found differences in the susceptibility of target organisms, which could (1) at least partly be a result of adaptation to the respective host plants and (2) indicate that allelopathic interference might reduce the abundance of some species, especially cyanobacteria, in epiphytic biofilms.     

Feeding response of Aphis pomi,Myzus persicae, and Amphorophora agathonica to phlorizin

Phlorizin, a phenolic compound present only in the apple genus, Malus, was found to be neutral as a probing stimulus to Aphis pomi, an apple feeder, but was a probing deterrent to the non-apple feeding aphids, Myzus persicae and Amphorophora agathonica. Phlorizin was an ingestion deterrent to all three species although the threshold was lower for A. pomi. Apple can be utilized as a host by A. pomi since it feeds in the phloem which appears not to contain phlorizin.     

Comparative studies on the life history of Angiostrongylus mackerrasae Bhaibulaya, 1968 and Angiostrongylus cantonensis (Chen, 1935)

The life history of A. mackerrasae was found to differ from that of A. cantonensis as follows: (1) the moulting times of A. cantonensis in the definitive host occurred a few days earlier than those of A. mackerrasae; (2) the growth rate of A. cantonensis was more rapid than that of A. mackerrasae. However, there were no differences in the migratory pattern of the third-stage larvae of both species in experimentally-infected definitive hosts. It is concluded that Mackerras & Sandars (1955) described the life history of A. mackerrasae and not A. cantonensis.     

Natural infections of aposymbiotic Cassiopea xamachana scyphistomae from environmental pools of Symbiodinium

The ability to acquire different types of the symbiotic dinoflagellate Symbiodinium (zooxanthellae) from the environment was investigated using aposymbiotic scyphistomae of the jellyfish Cassiopea xamachana. Non-symbiotic scyphistomae were placed on an offshore Florida patch reef and in Florida Bay during 3- and 5-day periods in March, and 5-day exposures in May, August and December of 2003. Scyphistomae were maintained in culture for several months, after which members of clades A, B, C and D Symbiodinium were detected in these hosts by denaturing gradient gel electrophoresis (DGGE) analyses. These findings contrast with naturally collected C. xamachana medusa from Florida Bay where all specimens possessed only Symbiodinium type A1. Furthermore, the polyps did not acquire the symbionts found in nearby cnidarian colonies, suggesting that a diverse pool of symbiont lineages exists in the environment. These results support previous laboratory studies where aposymbiotic hosts were initially non-selective and capable of acquiring many kinds of Symbiodinium. The specificity seen in adult hosts is likely a result of post-infection processes due to competitive exclusion or other mechanisms. A higher percentage of polyps became infected after 5 days of exposure, compared to 3 days, and no infections were observed in laboratory controls held in filtered seawater. Infections were lowest (50% at both sites) in March of 2003, when seawater temperatures were at their annual minima. Infection was 100% in scyphistomae exposed for 5 days during the months of May, August and December of 2003. These findings suggest that this host system, in addition to addressing questions of host-symbiont selectivity, can be employed to monitor and define the abundance and distribution of natural pools of Symbiodinium.     

Habitat preferences of two estuarine burrowing crabs Helice crassa Dana (Grapsidae) and Macrophthalmus hirtipes (Jacquinot) (Ocypodidae)

The horizontal and vertical distributions of two species of endemic, burrowing mud crabs Helice crassa Dana 1851 (Grapsidae) and Macrophthalmus hirtipes (Jacquinot 1853) (Ocypodidae) are described for the Avon-Heathcote Estuary (43°33′S: 172°44′E), Christchurch, New Zealand. Substratum preference is shown to be the most important factor influencing mud crab distribution, but lack of tolerance to salinities below 4‰ is also a significant factor preventing M. hirtipes from occurring at points close to freshwater input. Both species had similar sediment organic content and particle size requirements. Helice crassa was concentrated in well-drained, compacted sediments above mid-tide level, whilst Macrophthalmus hirtipeswas found in waterlogged areas below mid-tide level. This vertical separation is shown not to be caused by differential desiccation tolerances, but by feeding and burrowing adaptations related to these different substrata.     

Allelopathic potential of two invasive alien Ludwigia spp.

The allelopathic potential of two invasive alien Ludwigia [Onagraceae: L. peploides (Kunth) Raven and L. grandiflora (Michaux) Greuter and Burdet], that have developed quasi-monotypic stands in many aquatic ecosystems in France, was investigated. Since allelopathy involves the release of compounds into the environment, the water of monospecific experimental cultures was directly tested against two target species: Lactuca sativa L., the standard cultivar for bioassays, and Nasturtium officinale R. Brown, a resistant and widespread native hydrophyte. The treatment was carried out at the three main phases of development of both Ludwigia in February, May and August. For each experiment, the germination, mortality and culture yield percentages, the seedling growth (radicle and hypocotyl elongation) and the health of 15-day-old-seedlings were measured. The water of each Ludwigia tank induced: (1) a decrease in germination for watercress in August (control: 68.6%, L. peploides: 48.6%, L. grandiflora: 61.1%); (2) an increase in mortality in May only for watercress (control: 3.4%, L. peploides: 13.5%, L. grandiflora: 12%) and in August for both target species (up to 22.3% vs. 3% for lettuce and 27% vs. 12.5% for watercress); (3) a disturbance of seedling elongation for lettuce in all seasons; and (4) a seedling chlorosis of both target species, particularly in May and August. This study showed that L. peploides and L. grandiflora possess an allelopathic activity that influences the water quality throughout the year. Combined with the various competitive attributes, allelopathy may contribute to the great success of these two invasive Ludwigia in Europe. In threatened wetland communities of the Mediterranean area, in particular, allelopathy might have an important impact by diminishing the seedling survival of the most vulnerable species.     

枣园桃蛀果蛾寄生蜂种类及其与寄主的关系

桃蛀果蛾(Carposina sasakii Matsumura)是我国十分重要的果实性害虫,其中枣受害最严重,因其幼虫在果实内蛀食危害、高度隐蔽性的生活而较难防治。寻找有效天敌,开展生物防治成为必然。2009年与2010年研究调查了我国大枣部分产区陕西、山西、河南与宁夏枣园桃蛀果蛾寄生性天敌,共发现了3种寄生蜂,即中华齿腿姬蜂(Pristomerus chinensis Ashmead)、章氏小甲腹茧蜂(Chelonus(Microchelonus)zhangi Zhang)和金小蜂(Pteromalidae),3种寄生蜂均从桃蛀果蛾的茧中羽化而出,其中中华齿腿姬蜂和章氏小甲腹茧蜂为优势天敌,但它们表现出十分明显的地域性分布。同时,对中华齿腿姬蜂和章氏小甲腹茧蜂羽化、寄生率以及与寄主之间的关系进行了初步研究,结果表明,中华齿腿姬蜂越冬代成虫出蛰活动始于6月中旬,越冬代寄生率较低,第1代成虫羽化在8月下旬至9月上旬,这代寄生蜂具有较高的寄生率,可达25%;章氏小甲腹茧蜂第1代成虫羽化集中在8月中下旬和9月上旬,由于在2009年与2010年对样地进行不施用杀虫剂的管理,该天敌在2010年自然寄生率显著提高,最高时可达64.52%。因此,科学管理,合理保护与利用当地天敌成为实现该害虫生物防治的关键。