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Development of the pine moth (Dendrolimus pini Linnaeus, 1758: Lepidoptera, Lasiocampidae) on douglas fir (Pseudotsuga menziesii), spruce (Picea abies) und pine (Pinus sylvestris) under controlled conditions
No full textDevelopment of the pine moth (Dendrolimus pini Linnaeus, 1758: Lepidoptera, Lasiocampidae) on douglas fir (Pseudotsuga menziesii), spruce (Picea abies) und pine (Pinus sylvestris) under controlled conditions
No full textSurvival potential of the L(1)caterpillar of the pine beauty moth (Panolis flammea Linnaeus, 1758: Lepidoptera, Noctuidae) on may-shoots and mature needles of Scotch pine (Pinus sylvestris)
No full textThe feeding behaviour of the pine beauty moth ist controversially discussed in forest zoology with respect to whether the L-1-stages needs buds, fresh shoots, early may needles or mature needles for survival. To clarify this question parallel experiments under field and laboratory conditions have been performed. On April 1(st) 1999 540 eggs (Experiment A) and on May 2(nd) 1999 2 x 600 eggs (Experiment B, C) were exposed in a young mixed stand of pine and spruce near Waake (Southern Lower Saxony). 20 eggs in small Petri dishes each were caged on 3 m to 4 m high trees in 87 replications. All experiments lasted until June 7(th) 1999. In Experiment A (closed buds and mature needles at the time of transferring the eggs into the field) 16% of the L-1-larva survived (Fig. 1); in the Experiment B (commencing four weeks after Exp. A, with sprouting shoots and mature needles present) 48.5% of the larva survived (Fig. 2). In Experiment C (mature needles only) 0% of the larva survived (Fig. 3). At the end of the experiment the attacked shoots were examined regarding their condition. Almost exclusively galleries had been bored into the buds to get access to the young needles which were destroyed; however the stems of the shoots were seldom attacked. Parallel to the field experiments two experiments (D with may shoots, E without may shoots) were carried out under laboratory conditions with L-1-larvae but otherwise the same experimental design. As with the field experiment no larva survived when only mature needles were offered (Fig. 5). May shoots were attacked more heavily than in the field and eaten almost completely The development of the individuals of the respective populations was much more extended under field- than under laboratory conditions. It is clearly concluded from the experiments that the L-1-larva of Panolis flammea depends on young needles as its first Source of food, sprouting shoots are optimal, closed buds are attacked with minor survival success. The defence reaction of the tree by resin flow does not suppress the attack of the larva but reduces the survival rate
Development of the nun moth (Lymantria monacha Linnaeus, 1758: Lepidoptera, Lymantriidae) on Douglas fir (Pseudotsuga menziesii), spruce (Picea abies) and pine (Pinus sylvestris) under controlled conditions)
No full textLarvae of the nun moth (Lymantria monacha L.) were bred in parallel experiments on pine (Pinus sylvestris), douglas fir (Pseudotsuga menziesii) and spruce (Picea abies). The larvae were kept under constant conditions in climated rooms or climated chambers on cut branches, which were positioned in tap water. The effect of a temperature range between 16degreesC and 30degreesC and of two different population densities of larvae was examined. The speed of development, the larval mortality, the weight of the larvae and the resulting pupae depending on the tree species were noticed. The development of the larvae with high population density was marginally slower than in populations with low population density, causing slightly lower weights of the pupae in both sexes (Fig. 1, Fig. 4). Spruce is - depending on the examined parameters - the most suitable food source and even caused a faster development (Fig. 1) and higher pupae weights (Fig. 3, Fig. 4) in all temperature experiments. The mortality of the larvae, mainly due to the mortality of young and middle aged larvae, was significantly higher on douglas fir than on spruce or pine (Fig. 2). This result could indicate that the douglas fir is a more unfavourable tree species for the development success of the nun moth than spruce or pine. It is pointed out that results of experiments under controlled conditions can be transfered to field experiments only to a limited extent
Survival potential of the L(1)caterpillar of the pine beauty moth (Panolis flammea Linnaeus, 1758: Lepidoptera, Noctuidae) on may-shoots and mature needles of Scotch pine (Pinus sylvestris)
No full textThe feeding behaviour of the pine beauty moth ist controversially discussed in forest zoology with respect to whether the L-1-stages needs buds, fresh shoots, early may needles or mature needles for survival. To clarify this question parallel experiments under field and laboratory conditions have been performed. On April 1(st) 1999 540 eggs (Experiment A) and on May 2(nd) 1999 2 x 600 eggs (Experiment B, C) were exposed in a young mixed stand of pine and spruce near Waake (Southern Lower Saxony). 20 eggs in small Petri dishes each were caged on 3 m to 4 m high trees in 87 replications. All experiments lasted until June 7(th) 1999. In Experiment A (closed buds and mature needles at the time of transferring the eggs into the field) 16% of the L-1-larva survived (Fig. 1); in the Experiment B (commencing four weeks after Exp. A, with sprouting shoots and mature needles present) 48.5% of the larva survived (Fig. 2). In Experiment C (mature needles only) 0% of the larva survived (Fig. 3). At the end of the experiment the attacked shoots were examined regarding their condition. Almost exclusively galleries had been bored into the buds to get access to the young needles which were destroyed; however the stems of the shoots were seldom attacked. Parallel to the field experiments two experiments (D with may shoots, E without may shoots) were carried out under laboratory conditions with L-1-larvae but otherwise the same experimental design. As with the field experiment no larva survived when only mature needles were offered (Fig. 5). May shoots were attacked more heavily than in the field and eaten almost completely The development of the individuals of the respective populations was much more extended under field- than under laboratory conditions. It is clearly concluded from the experiments that the L-1-larva of Panolis flammea depends on young needles as its first Source of food, sprouting shoots are optimal, closed buds are attacked with minor survival success. The defence reaction of the tree by resin flow does not suppress the attack of the larva but reduces the survival rate
The "Length of branches with leaves (LbT)", a new index to compare insect densities on trees of different expansion
No full textSome hundred small-sized Aspen (Populus tremula) and Willow trees (Salix caprea) occurring at the forest edge were examined since 1997 in Lower Saxony. Several thousand phytophagous insects, mainly larvae of the family Lepidoptera, were found on the trees. The objective was to compare the habitat preferences of the insects in relation to the type of forest edge and one practical problem which presented itself was find a way of describing the size of each examined tree. The shape of trees at the forest edge differs from the ideal tree shape encountered inside a forest, and the commonly used parameters like height or crown volume are not helpful when describing the volume of leaves and branches which may be used as habitat by phytophagous insects (Fig. 2 and 3). Therefore, a new parameter, the "Length of branches with leaves (LbT)", has been developed. All branches with leaves longer than 10 cm are measured from the basis of the first leaf to the top of the branch. The sum of all the leafed branch lengths, measured in metres, is designated as LbT for every tree (Fig. 1). The number of larvae of Lepidopterans on the examined tree, divided by LbT is used as an index of preference, for a single taxon, a group of taxa or all individuals found on a single tree or either a special group of trees (Fig. 5, Tab. 1 and 2). This index, known as the "edge habitat preference" enables the comparison of the settling density of the taxon or the insect group of interest in relation to defined tree classes/species. The quantity LbT is relatively easy to assess in the field and can be used to compare shrubs and trees with very different shapes and sizes (Fig. 4). In addition the changes of tree shapes resulting from natural growth or possible damage by browsing or cutting may be assessed, if trees are examined repetitively
The "Length of branches with leaves (LbT)", a new index to compare insect densities on trees of different expansion
No full textSome hundred small-sized Aspen (Populus tremula) and Willow trees (Salix caprea) occurring at the forest edge were examined since 1997 in Lower Saxony. Several thousand phytophagous insects, mainly larvae of the family Lepidoptera, were found on the trees. The objective was to compare the habitat preferences of the insects in relation to the type of forest edge and one practical problem which presented itself was find a way of describing the size of each examined tree. The shape of trees at the forest edge differs from the ideal tree shape encountered inside a forest, and the commonly used parameters like height or crown volume are not helpful when describing the volume of leaves and branches which may be used as habitat by phytophagous insects (Fig. 2 and 3). Therefore, a new parameter, the "Length of branches with leaves (LbT)", has been developed. All branches with leaves longer than 10 cm are measured from the basis of the first leaf to the top of the branch. The sum of all the leafed branch lengths, measured in metres, is designated as LbT for every tree (Fig. 1). The number of larvae of Lepidopterans on the examined tree, divided by LbT is used as an index of preference, for a single taxon, a group of taxa or all individuals found on a single tree or either a special group of trees (Fig. 5, Tab. 1 and 2). This index, known as the "edge habitat preference" enables the comparison of the settling density of the taxon or the insect group of interest in relation to defined tree classes/species. The quantity LbT is relatively easy to assess in the field and can be used to compare shrubs and trees with very different shapes and sizes (Fig. 4). In addition the changes of tree shapes resulting from natural growth or possible damage by browsing or cutting may be assessed, if trees are examined repetitively
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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