5,006 research outputs found

    Between-Site Variation in Suitability of \u3ci\u3eSalix Cordata\u3c/i\u3e as a Host for \u3ci\u3eAltica Subplicata\u3c/i\u3e (Coleoptera: Chrysomelidae)

    Get PDF
    To investigate local adaptation of insect herbivore populations to host plant populations, willow flea beetles (Altica subplicata) were collected from two distant sites in northern Michigan (Grass Bay, GB; Pte. Aux Chenes, PAC) and reared on host plants (Salix cordata) collected from each of the sites. Larval development (measured by molt frequency and length of larval stage) was significantly faster on PAC plants than on GB plants but did not differ for the two beetle populations. For both populations of beetles, mean pupal weight was also greater on PAC plants than on GB plants. Thus, there was no evidence for adaptation of beetle populations to local host plant populations. The greater performance of A. subplicata on PAC plants most likely resulted from a lower trichome density on leaves of plants from that site

    Feeding Patterns and Attachment Ability of \u3ci\u3eAltica Subplicata\u3c/i\u3e (Coleoptera: Chrysomelidae) on Sand-Dune Willow

    Get PDF
    To investigate feeding patterns of a specialist herbivore, Altica subplicata, larvae and adults were caged separately on host plants, Salix cordata, and leaf damage was estimated. Young, relatively more pubescent leaves near the tops of the shoots were consumed more than older leaves. Larvae clearly preferred the young, pubescent leaves and avoided the oldest leaves. Adults showed a stronger preference for the first five young leaves, but amount of consumption did not differ among the older leaves. Attachment ability on smooth and pubescent leaves was examined as a possible factor influencing feeding patterns. Scanning electron microscopy of tarsal adhesive structures and leaf surfaces was conducted to investigate how A. subplicata attaches to its host. Adhesive setae on the tarsi of adults may be effective for attachment on the older, smooth leaves and their tarsal claws are likely used to cling to trichomes of pubescent leaves. Larvae have fleshy adhesive pads for attachment. Laboratory experiments on attachment of larvae and adults to smooth and pubescent leaves under various wind conditions showed that wind caused difficulty in attachment and movement, but leaf pubescence did not affect the number of beetles that fell off leaves. However, larvae fell off more quickly when placed on pubescent leaves. Thus, other factors such as nutritional quality and microclimate provided by trichomes may be responsible for the preference for pubescent leaves exhibited by A. subplicata

    Forest Return on an Abandoned Field - Secondary Succession Under Monitored Conditions

    Get PDF
    The secondary succession pattern observed on an arable field abandoned since 1974 in Tilio-Carpinetum habitat is described and disscussed. Results obtained during 36 years of study confirm that succession on an abandoned field leads from a typical segetal community to the formation of a juvenile treestand composed of pioneer species. Our study supports the view that succession is a process which is largely dependent on the initial conditions and surrounding vegetation. The results indicate that some species can modify the course of this process, accelerating or slowing it down. Limitations of the method and prognosis of future vegetation development are also discussed

    Aggregation Behavior of a Willow Flea Beetle, \u3ci\u3eAltica Subplicata\u3c/i\u3e (Coleoptera: Chrysomelidae)

    Get PDF
    This study examined the aggregation behavior of a specialist insect herbivore, Altica subplicata (Coleoptera: Chrysomelidae), on its host plant, Salix cordata. Mark-recapture experiments were conducted in patches of S. cordata growing along the shores of Lake Huron. Beetles aggregated on individual host plants, but did not aggregate in larger areas containing many host plants. Plants colonized by marked beetles had significantly higher abundances of unmarked beetles than did plants that were not colonized by marked beetles. Experimental manipulations of the number of beetles present on plants showed that colonization rates by marked beetles were higher on plants with conspecifics than on plants which had all beetles removed the previous day. The sex of beetles, however, did not influence colonization behavior; both male and female beetles colonized plants regardless of the sex of beetles already present on plants. These results are discussed with respect to possible explanations for aggregation, and the role of aggregation and movement in influencing insect distributions

    Effects of Soil Moisture on the Pupation Behavior of \u3ci\u3eAltica Subplicata\u3c/i\u3e (Coleoptera: Chrysomelidae)

    Get PDF
    The effects of soil moisture on the pupation behavior of a willow flea beetle, Attica subplicata, were studied with two laboratory experiments. To test the effect of soil moisture on the number of larvae pupating and pupal survival, we set up pupation chambers filled with sand with three different soil moistures: dry, moist, and wet. The number of larvae pupating was much greater in the moist sand and wet sand treatments than in the dry sand treatment. Pupal survival, as measured by the proportion of adults successfully emerging, was greater in the moist treatment than in the wet or dry treatments. Thus, overall pupation success (number of adults successfully emerging) was greater in the moist treatment than in the wet treatment and greater in the wet treatment than in the dry treatment. To examine the effect of soil moisture on choice of pupation site, we provided the larvae with a choice of two soil moistures in each pupation chamber. More larvae chose wet over dry conditions and more chose moist over dry conditions, but larvae did not discriminate between moist and wet conditions. The improved pupation in areas with higher soil moisture is consistent with the field distribution pattern of greater beetle densities on dunes with greater soil moisture

    A phytosociological survey of the boreal forest (Vaccinio-Piceetea) in North America

    Get PDF
    A survey of syntaxa of vegetation of North American boreal forests (class Vaccinio-Piceetea) is presented. This phytosociological survey, carried out combining the Braun-Blanquet method with numerical syntaxonomical analyses (cluster and correspondence analysis), describes the associations of the North American boreal forests, which have several species, varieties or vicariant species in common with their Eurasian counterparts, and can be placed in the class Vaccinio-Piceetea. By means of tabular and multivariate analyses, 2084 North American relevés were compared with 3273 relevés from European, Japanese and Korean boreal forest, to describe and typify 4 orders, 10 alliances and 37 associations. Diagnostic tables, ordination, clustering, and climatic, edaphic and biogeographical data were used to show floristic affinities among these syntaxa and interpret their distribution areas. Syntaxa were briefly characterized by their floristic composition, physiognomy, succession, zonation, and biogeographical distribution

    Lichens and allied fungi of old parks of three museum-reserves in Moscow Region (Russia)

    Get PDF
    We present the results of lichenological research in the parks of the museum-reserve Abramtsevo, the museum-reserve of A. S. Pushkin and the museum-estate Ostafyevo – Russian Parnassus, for which no previous data were available. The checklist of lichen biota contains 103 species including 98 lichens, a lichenicolous fungus and 4 non-lichenized fungi. 55 species were found in the park of the museum-reserve Abramtsevo, 58 species in the museum-reserve of A. S. Pushkin (estates Vyazemy – 51 and Zakharovo – 29) and 69 species in the museum-estate Ostafyevo – Russian Parnassus. Lichenochora obscuroides (Ostafyevo) is new for Central Russia. Cladonia macilenta, Evernia prunastri and Usnea hirta (Ostafyevo) are listed in the Red Data Book of Moscow. Parmelina tiliacea (Abramtsevo, Vyazemy), Ramalina farinacea, Usnea dasopoga and U. subfloridana (Abramtsevo) are listed in the Red Data Book of the Moscow Oblast. Chaenotheca chrysocephala, Melanelixia subargentifera, Parmelina tiliacea, Physconia perisidiosa and Ramalina europaea (Ostafyevo) are proposed for inclusion in the next edition of the Red Data Book of Moscow

    Афілофороїдні гриби Регіонального ландшафтного парку «Ізюмська лука» та прилеглих територій (Харківська область, Україна)

    Get PDF
    Two hundred and eight species of aphyllophoroid fungi (Basidiomycota) were revealed by us in “Iziumska luka” Regional Landscape Park and vicinities (Ukraine, Kharkiv region, Steppe natural zone) during 2007-2010. Of them, 202 species are firstly reported for the research area. Fourteen species are revealed for the first time in Ukraine. They are Athelia bombacina (Link) Pers., A. salicum Pers., Boidinia furfuracea (Bres.) Stalpers et Hjortstam in Hjortstam et Stalpers, Ceraceomyces tessulatus (Cooke) Jülich, Hypochnicium geogenium (Bres.) J. Erikss., Loweomyces fractipes (Berk. et M.A. Curtis) Jülich, Phellinus rhamni (Bondartseva) H. Jahn, Piloderma lapillicola Jülich, Sistotrema resinicystidium Hallenb., S. sernanderi (Litsch.) Donk, Trechispora praefocata (Bourdot et Galzin) Liberta, Tulasnella pinicola Bres., T. pruinosa Bourdot et Galzin and Vuilleminia cystidiata Parmasto. In the case of 4 species, i.e. Fibriciellum silvae-ryae J. Erikss. et Ryvarden, Hyphodontia tuberculata Kotir. et Saaren., Sistotremella hauerslevii Hjortstam and Trechinothus smardae (Pilát) E.C. Martini et Trichies, “Iziumska luka” is the first and still single area of occurrence reported from the Eastern Europe. Together with 1 species known from the research territory before our study, the total list of aphyllophoroid fungi of this forest massif now comprises 209 species and is presented in the paper with information on their substrata. Remarks are provided both for taxonomically and mycofloristically important records

    Risk of root intrusion by tree and shrub species into sewer pipes in Swedish urban areas

    Get PDF
    Blockages in sewer pipes caused by roots are very common and several tree and shrub species are reported to be particularly likely to cause root intrusion. This study examined the relative ability of roots of different species to intrude into urban sewer pipes. Data on root-intruded pipes and the woody plants surrounding these pipes were collected from two Swedish cities, Malmö and Skövde. Plant material, location data and closed-circuit television (CCTV) inspections on root-intruded pipes with a total length of 33.7 km, containing 2180 different points of root intrusion, were examined. An inventory of 4107 woody plants was compiled. The results showed that broad-leaved trees dominated as a cause of root intrusion, but that conifers and a number of shrubs, e.g. the genera Ligustrum, Spiraea and Syringa, were also likely to have caused root intrusion. Malus floribunda Van Houtte was found to have the highest mean share of root intrusions per estimated number of pipe joints when all joints and all root intrusions within a 10 m radius from trees were calculated (0.694, maximum number of intrusions per joint 1.0), while Populus canadensis ‘Robusta’ Moench had the second highest, with 0.456 intrusions per estimated joint. However, other Malus and Populus species and cultivars had a much lower mean share of root intrusions. Most species seemed capable of causing root intrusion, and not only species of the genera Populus and Salix that were previously seen as the species most likely to cause damage to stormwater and sewer systems. There were differences in the frequency of joint intrusion by roots of different species, but the reasons for these differences were not identified and further research in the area is needed
    corecore