Sirococcus conigenus,Sirococcus piceicola sp. nov. and Sirococcus tsugae sp. nov. on conifers: anamorphic fungi in the Gnomoniaceae,Diaporthales

Sirococcus is a genus of asexually reproducing fungi that includes important pathogens causing shoot blight and tip dieback of conifers. In this paper, the type species of Sirococcus, S. conigenus, is redescribed and illustrated, and an epitype designated. In addition, two new species are recognized. Sirococcus piceicola sp. nov. is described from species of Picea in Canada and Switzerland. A second new species, S. tsugae sp. nov., is known only from western North America on species of Cedrus and Tsuga. These three species can be distinguished based on morphological differences and molecular sequence data from four genes. The three species of Sirococcus on conifers vary in conidiomatal wall structure, shape of the conidiogenous cells, and shape and size of conidia.     

Chalara fraxinea sp. nov. associated with dieback of ash (Fraxinus excelsior) in Poland

A new species of the hyphomycete genus Chalara is described. It has been frequently isolated from stems and branches and sometimes also from roots of wilting and dying Fraxinus excelsior in Poland. It differs from previously described species of Chalara by its small, short cylindrical phialoconidia extruded in chains or in slimy droplets, morphological features of the phialophores and by colony characteristics. It is non‐tolerant to cycloheximide.     

Corsican Pine (Pinus nigra var. maritima (Ait.) Melville) in Southern Britain: A Study of Growth and Site Factors

Measurements of fifty crop and site factors in thirty plantedCorsican pine stands in south and east England were subjectedto multivariate analysis by the method of principal components.The correlations between components describing crop and sitesuggest that low winter minimum temperatures affect growth ofCorsican pine more than warmth in the growing season. A componentgrouping soil total phosphate levels and soil pH also appearsto be causally related to growth potential whereas other componentsdescribe variables considered to result from the effects ofa tree crop. The site water balance, as reflected by growingseason rainfall, potential evaporation, and water storage inthe soil is apparently unrelated to growth differences.     

Descriptions of Leptomastidea angulipennis sp. nov. and two known species of Leptomastidea(Hymenoptera:Encyrtidae),with a key to Chinese species

Leptomastidea angulipennis sp. nov. is described as new to science from Yunnan, China. It can be easily separated from all the other species of the genus by the triangular shape and infuscate pattern of the forewing.Brief diagnoses and new distributional data of L. herbicola and L. rubra are also provided, and a key to the females of all the Chinese species is given.     

Alley cropping rice (Oryza sativa var.Barafita) with cassia (Cassia siamea): soil fertility and crop production

Rice grain weight and quality (weight of larger size fractions), soil pH, and N, P, K and organic matter content were studied where rice was alley cropped with cassia on a semiarid site in The Gambia. The four treatments, control (no cassia prunings or inorganic fertilizer added), only prunings added, prunings plus half the recommended fertilizer rate and prunings plus full recommended rate of fertilizer, were applied in a Latin square design with 10×8 m plots, each sub-divided into two 4-m wide alleys. Fertilizer was applied twice; full rates were 93.7 kg/ha NPK (8:24:24) plus 32.4 kg/ha urea followed two weeks later by 100 kg/ha urea applied as side dressing. Soil samples collected before and after cropping at 0–10 cm and 10–15 cm depths and cassia pruning samples were analyzed for pH, N, P, K and organic matter content.Our results do not show significant benefit of cassia prunings applied as mulch to grain weight or quality in alley cropping rice with cassia. The addition of inorganic fertilizer plus cassia prunings did not increase rice grain and straw weights (p=0.3447 and p=0.0691, respectively) compared to the control and prunings only treatments. In all treatments, the outer rows, those within 80 cm of hedgerows, produced significantly less grain (p=0.0002) and straw than inner rows. Neither the larger grade A nor the smaller grade B grain weights were significantly different (p=0.6017 and p=0.0629, respectively) between treatments. Weight of grain, straw, and larger grade A and smaller grade B quality grain did not differ significantly for inner and outer rows (p=0.6329, p=0.7148, p=0.7171 and p=1.000, respectively).     

Relationships between mass mortality of two oak species (Quercus mongolica Turcz. var.grosseserrata Rehd. et Wils. andQ. serrata Thunb.) and infestation by and reproduction ofPlatypus quercivorus (Murayama) (coleoptera: Platypodidae)

This study investigated the number of adults ofPlatypus quercivorus (Murayama) captured on host oak (Quercus spp.) trees, the attack density (the number of entry holes per 100 cm²), and the number of emerging adults to clarify the relationships between the beetle’s colonization on trees in oak stands and tree mortality. The initial attack ofP. quercivorus, which was the most intense attack, was observed on most living trees simultaneously. Although some attacked trees died within the year of the attack or in the next year, a high density of attack did not usually cause the death of host trees. Surviving trees suffered low levels of consecutive attack after the initial attack. BecauseP. quercivorus successfully produced broods only in the dead trees, the population of the insect seems to be maintained only in stands where oak mortality occurs. However, the adults that landed on most of the surviving trees appeared unable to reproduce probably due to degradation of host quality. Thus, oak mortality probably ceases within 3 or 4 years after the start of infestation in a stand, with subsequent reductions in population density of the borer.     

Auswirkungen des Einsatzes entomopathogener Nematoden (Heterorhabditis sp.) im Freiland auf die Nichtzielfauna, 2. Teil: Diptera

The effects of entomopathogenic nematodes on nontarget Diptera of terrestrial ecosystems were investigated for the first time in the field. Experiments were conducted 1989 at four sites near Darmstadt (FRG) (mixed deciduous forest, forest border, orchard and summer wheat field). In field trials the nematode strainHeterorhabditis HL 81 was distributed at concentrations of 10⁶ ind./m² on plots of 100m² each. Diptera were sampled using emergence traps set on soil (photoeclectors) over a period of five to six weeks after nematode application. The obtained results demonstrate, that only in some cases an appreciable parasitation of Diptera by the employed nematode strain may have occurred. Only on one site (orchard) a significant reduction (α≦0,05) of several nontarget species of families was observed. On the contrary, in each of the four nematode plots some species or families emerged at higher rates compared with the untreated plots. Other causes for the unequal distribution of Diptera than the parasitation throughHeterorhabditis are discussed. The detrimental effects of a field application of entomopathogenic nematodes on the nontarget insect fauna must be considered negligible at the present state of knowledge.     

毒蘑菇菌株及毒素粗提液对樟子松枯梢病菌生长的影响

厚环鹅膏、鹅膏菌、珊瑚菌、白霜杯伞、冠状柄环菇、细鳞环柄菇、鳞柄白鹅膏、绒白乳菇、毒蝇鹅膏9个毒蘑菇菌株及毒素粗提液对樟子松枯梢病原菌菌丝生长影响的研究结果表明:除厚环鹅膏和鹅膏菌外,其他7个菌株对病原菌生长均有一定的抑制作用;鳞柄白鹅膏和细鳞环柄菇相对抑制效果最好,分别为10.80和10.40。除毒蝇鹅膏外,其他8个菌株的毒素粗提液对病原菌菌丝生长均有一定的抑制作用,珊瑚菌和绒白乳菇毒素粗提液的抑菌效果最好,抑菌率分别达到63.89%和58.89%。     

Yield and growth features of Panicum maximum (Jacq.) var Trichoglume cv Petrie (Green Panic) under woody cover,Chaco region,Argentina

Secondary forests and shrub thickets with low suitability for cattle raising are widespread in the Chaco region (NW Argentina). Concerns about the ecological sustainability of these ecosystems favor vegetation clearing methods for improving standing forage and accessibility for livestock operations that retain native tree and shrub species, a system called ‘silvopasture’ locally. These areas are characterized by a reduction of sunlight availability if compared with treeless pastures. The objective of this research was to assess the growth rate and the effect of two harvesting intervals (15 and 30 days) on the annual yield (BM) and forage quality of Panicum maximum (Jacq.) var Trichoglume cv Petrie (Green Panic) in such a system, using two approaches: successive harvests and functional, during three growth seasons (2000–01, 2001–02 and 2002–03). Correlation of growth features of Green panic with rainfall (mm), growing degree days (°C, GDD), and soil moisture (%) at two soil depths (0–15 and 15–30 cm) was also assessed. BM varied between 3,500 and 11,500 kg dry matter ha^?1. The absolute growth rate presented two annual peaks, located in early and late summer, irrespective of growth season and harvesting interval. Growth season and harvesting interval significantly affected the relative growth rate (p > F = 0.0015 and p > F = 0.0002, respectively). BM was significantly correlated with rainfall and GDD observed between sampling dates, the magnitude of the coefficients were higher for the 30-day than for the 15-day harvesting interval. Correlation between BM and soil moisture content was not significant for both soil depths. Resting periods should be longer than 30 days to maintain the stability of the grazing system.     

The northernmost plant pathogenic fungus,Rhytisma arcticum sp. nov.: Morphological and molecular characterization of a novel species from Ellesmere Island,Canada

A novel fungal pathogen, Rhytisma arcticum, is described, causing tar spot disease on Salix arctica in Ellesmere Island, Canada. Stromata, asci and ascospores—distinctly smaller than other Rhytisma species found on Salix—are its distinctive morphological features. rDNA internal transcribed spacer (ITS) and large-subunit (LSU) sequence analyses revealed a close relation of this species to R. polare previously reported on Spitsbergen Island. This study describes a novel plant pathogen species in one of the northernmost locations of the world.     

Alley cropping maize (Zea mays var.Jeka) with cassia (Cassia siamea) in The Gambia: crop production and soil fertility

The relative contributions of cassia prunings and inorganic fertilizer to yield of maize (number of ears and weight of grain, ears, cobs and stover), maize grain quality (weight of 3 largest size fractions) and soil pH, N, P, K and organic matter contents were investigated at a semi-arid site in The Gambia. Four treatments: control (no prunings or fertilizer applied), only prunings applied, prunings plus half the recommended rate of fertilizer, and the full recommended fertilizer rate plus prunings, were replicated in a Latin square design. At the full fertilizer rate, 125 kg/ha of NPK (82424) plus 43.5 kg/ha urea was broadcast at the time of sowing followed by 100 kg/ha of urea applied as side dressing two weeks after crop germination. Soil N, P, K organic matter and pH were not significantly different either before cropping or after crop harvest in both 0–10 and 10–15 cm soil depth.Crop yield, as measured by number and dry weight of ears, stover, grain and cob weights, was significantly different among treatments (p=0.0001, p=0.0001, p=0.0001, p=0.0001 and p=0.0001, respectively). The application of prunings plus full recommended fertilizer produced the highest yields. The weights of the three largest grain size fractions, grades A, B, and C, differed significantly between treatments (p=0.0026, p=0.0001 and p=0.0001, respectively). Yield of grade A grain increased by 202% over control with application of prunings plus full rate fertilizer and declined by 31% relative to the control with application of only prunings. More grade A, B and C grain was produced with application of full rate fertilizer plus prunings than in control treatments. However, application of half rate fertilizer plus prunings produced a higher proportion of grade A grain.     

Effect of temperature on development, mortality, fecundity, and reproduction of Aphis rumicisL. (Homoptera: Aphididae) on broadleaf dock (Rumex obtusifolius) and Swiss chard (Beta vulgaris vulgaris var. cida)

Temperature effects on developmental period, survival rate, and reproductive capacity of Aphis rumicis L. were studied on Broadleaf dock and Swiss chard at four constant temperatures (17.5°C, 20°C, 22.5°C, and 25°C). The developmental time of immature stages ranged from 10.9 days at 17.5°C to 6.5 days at 25°C on Broadleaf dock, and 11.8 days at 17.5°C to 6.5 days at 25°C on Swiss chard. The total percentage of survivorship of immature stages varied from 54.2% and 67.6% 17.5°C–25°C on Broadleaf dock, and 49.7% and 62.4% at 17.5°C–25°C on Swiss chard. The largest r _m value occurred with 0.2845 at 25°C on Broadleaf dock and with 0.2785 at 25°C on Swiss chard. The results obtained on this study indicated that Swiss chard was a less favorable host of the A. rumicis than Broadleaf dock. The optimal temperature for A. rumicis growth, developmental time, and reproduction was 22.5°C–25°C.     

Results and perspectives in the use ofBacillus thuringiensis Berl. var.kurstaki and other pathogens againstThaumetopoea pityocampa (Den. et Schiff.) in Italy (Lep., Thaumetopoeidae)

The pine processionary caterpillar,Thaumetopoea pityocampa is the most important defoliator of both native and introduced pines throughout Italy and is especially damaging in young plantations and on ornamental trees. A number of microbial pathogens have been isolated from larvae and pupae over the last 30 years. Some of them have been evaluated as biological control agents, and have provided encouraging results. However, onlyBacillus thuringiensis var.kurstaki (Btk) has passed the experimental screening and is now available for routine treatments, although its application by air is subjected to strict regulation by the government. The erratic performance of a single application ofBtk againstT. pityocampa that has been observed in the field (20–85% mortality) is related to a great variability in both the application dose and some population parameters ofT. pityocampa. The emergence period of adults varies from July (Alps) to October (South) and its duration is related to the spreading of the cohorts (individuals with different length of prolonged diapause) over time. In addition, embryonic development takes from 20 to 45 days, depending strictly on the temperatures recorded in the egg masses. As a result, the most vulnerable larval instars (L1 and L2) are never thoroughly reached by one application only, as the persistence of the bacteria on the needles is usually limited. Two applications are requested to control the pest in stands where the egg hatching occurs over more than one month. Another possibility consists of a single winter application against L3−L4 with a higher dose, to be performed where a certain amount of damage is tolerated.     

Pathogenicity of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) Isolates to the Ailanthus Webworm,Atteva fabriciella (Lepidoptera: Yponomeutidae) Under Laboratory and Field Conditions

The virulence of 25 Metarhizium anisopliae isolates was tested under laboratory conditions and the two most effective isolates were evaluated in the field for control of the Ailanthus defoliator, Atteva fabriciella. A bioassay was carried out to determine the dose and time mortality responses. The LC₅₀ of the isolates ranged from 3.16 to 647.81?×?10⁵ conidia mL^?1. Toxicity tests of the isolates MIS7 and MIS13 and 0.5% Pongamia pinnata seed oil, individually and in different combinations, indicated improved efficacy of the isolates when used in combination and also when combined with seed oil. Evaluation of these formulations in the field showed 66.36% reduction of infestation with MIS7 + MIS13 + 0.5% P. pinnata seed oil and 61.15% reduction with MIS7 + MIS13. The study indicated a possibility of employing combined formulations of M. anisopliae and also combination with P. pinnata seed oil for augmenting the effectiveness of the fungus.     

Bark beetle (Coleoptera, Scolytidae) outbreak and system of IPM measures in an area affected by intensive forest decline connected with honey fungus (Armillaria sp.)

The character of a bark beetle outbreak, planning system, and implementation of IPM measures in a forest affected by intensive decline connected with honey fungus (Armillaria sp.) is described. It is possible to distinguish two levels of outbreak in the study area. The first level is characterized by spruce mortality connected with yellowing of spruce and presence of plant pathogens, mostly Armillaria sp. Forest stands have disperse infestations of bark beetles. Identification of infested trees and salvage cutting in time are problematic. In case of late processing of infested trees, the second level of outbreak could become manifest. The populations of bark beetle increase. Beetles could attack relatively healthy trees. The classical outbreak with forest edges and spot infestations starts. The identification of infested trees is easier. The application of pheromone trap barriers is effective. Thus, the second level of outbreak could be easily managed. The planning of IPM measures is concerned with localization of various pheromone trap systems in particular forest stands. It is based on field survey, data acquisition, estimation of swarming bark beetle population, and information of pheromone system effectiveness.     

Phenology, damage and parasitoids of the apple leaf cutter Coenorhinus pauxillus (Germ.) (Col.: Attelabidae)

An outbreak on apple permitted a closer look at Coenorhinus pauxillus (Germar) (Col.: Attelabidae). The adult weevils emerge from mid-March onwards and attack the first unfolding leaves. Infested leaves drop when the larvae are in the 1^st or 2^nd instar, and it takes a further 4 weeks before the larvae are ready to pupate. Rearing of field-collected eggs and larvae is described. Leaf decomposition is an essential condition for pupation, as the fully-grown larvae do not leave their mine actively. Part of the population pupates more or less immediately and produces adult weevils in autumn. However, up to 70?% of the weevils remain in prolonged diapause; their pupation does not take place before the summer of the following year. Damage by the weevil involves not only the loss of leaves of flower clusters and shoots, but also feeding damage to young fruits. Two parasitoids were found. Observations indicate that 3?–?4 subsequently more abundant generations of Anaphes brachygaster Debauche (Hym.: Mymaridae) develop in eggs of C. pauxillus. Probles brevicornis Horstmann (Hym.: Ichneumonidae, Tersilochinae) emerges in May and oviposits in young weevil larvae on the tree. The parasitoid does not develop into a pupa until its host starts pupating. The outbreak of apple leaf cutter did not decline over three years, but did not spread into adjacent plantings.     

The pine wood nematode Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (=B. lignicolus Mamiya and Kiyohara): an assessment of the current position

Pine wood nematode, Bursaphelenchus xylophilus (Steiner andBuhrer) Nickle, is the casual organism of pine wilt disease,a major tree killer in the Far East. This paper describes thebiology of B. xylophilus, particularly its inter-relationshipswith vector insects in the genus Monochamus (Coleoptera: Cerambycidae),tree species and environmental conditions. The principal methodof transmission, and hence of international plant health significance,is introduction of nematodes to susceptible dying or dead treesduring female oviposition. This occurs in all countries wherethe nematode occurs but is the only significant method of transmissionand survival of B. xylophilus in North America. Extensive treemortality in Japan and China is associated with presence ofhighly susceptible tree species, suitable vector species andhigh summer temperatures. Pest risk assessments have been carriedout to determine the risks to Europe; it is concluded that thenematode would undoubtedly survive in Europe but that tree mortalityis likely only in the warmer southern countries. Methods toprevent transfer of nematodes to Europe are discussed in relationto European Union legislation.     

Inoculation of Picea abies (L.) Karst. seedlings with vegetative inocula of ectomycorrhizal fungi Suillus bovinus (L.: Fr.) O. Kuntze and Inocybe lacera (Fr.) Kumm.

Perlite-peat substrate (2:1 v:v) fumigated with Basamide was inoculated with vegetative inocula (a mixture of perlite and peat moistened with the MMN liquid medium) of ectomycorrhizal fungi Suillus bovinus (isolate TUZ 105) and Inocybe lacera (isolate X/14) immediately before seeding with Norway spruce (Picea abies [L.] Karst.) in a nursery bed. Suillus inoculum was applied at rates of 0.5; 1.0; 1.5 and 2.0 litres per m², Inocybe inoculum at rates of 0.5 and 1.5 litres per m². At the end of the first growing season, all inoculation treatments showed a significantly greater mycorrhizal infection of bareroot seedlings compared to that found in both fumigated and unfumigated controls. The ectomycorrhizal 1-year-old seedlings were transplanted into containers. At the end of the second year, ectomycorrhizal infection of the 2-year-old container-grown seedlings was considerably less than that of the 1-year-old barerooted seedlings, probably as a consequence of too high fertility and/or insufficient porosity/aeration of pure peat moss medium. There was no difference in seedling growth between inoculated and uninoculated seedlings throughout the experiment.     

Nasekomie Dwukridlie Tom II,Wip.3: Komari-Dolgomoschki (Sem.Tipulidae) Podsem.Tipulinae: rodTipula L. (Tschast 1)

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