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- Anderbrant, O.
(författare)
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A model for the temperature and density dependent reemergence of the bark beetle Ips typographus
- 1986
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Ingår i: Entomologia Experimentalis et Applicata. - : Wiley. - 0013-8703. ; 40:1, s. 81-88
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Tidskriftsartikel (refereegranskat)abstract
- A model is presented that describes the reemergence of parent spruce bark beetles, Ips typographus, based on breeding density and temperature conditions. Laboratory data obtained at one constant temperature provide the distribution of reemergence time and different combinations of threshold temperatures and degreedays (°D) at mean reemergence. Of these combinations, 167.71 °D above 7.5 °C gave the best correspondence between model prediction and field data obtained from densely infested standing trees. The model was in good agreement with the reemergence pattern found for two groups of infested logs under different temperature conditions when adjusted for the lower breeding density. The applicability of the model in the study of bark beetle reproductive biology and in forest management is discussed. The method used to construct the model should be useful in developing other models for poikilothermic processes. Modèle déconivant la réémergence d'Ips typographus en fonction de la température et de la densité Ce modèle décrit la réémergence d'adultes d'I. typographus L. (Coleoptera, Scolytidae) en fonction de la densité et de la température. Les résultats obtenus en laboratoire à des températures constantes fournissent la distribution des réémergences et pour les dates de réémergence moyenne les différentes combinaisons de température de seuil et de degré de jour (°D). De toutes ces combinaisons, 167.71 °D au‐dessus de 7,5 °C fournit la meilleure concordance entre les prévisions du modèle et les observations dans la nature à partir d'arbres fortement attaqués. Le modèle a montré un bon accord avec la réémergence observée dans deux groupes de branches attaquées dans différentes conditions de la température quand il a été ajusté aux faibles densités d'élevage. La discussion examine les possibilités d'application du modèle à l'étude de la biologie de la reproduction d'I. typographus et à l'aménagement forestier. La méthode utilisée pour construire le modèle pourrait être employée pour en développer d'autres chez des poikilothermes. 1986 The Netherlands Entomological Society
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| 2. |
- Anderbrant, O.
(författare)
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Dispersal of reemerged spruce bark beetles, Ips typographus (Coleoptera, Scolytidae) : a mark‐recapture experiment
- 1985
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Ingår i: Zeitschrift für Angewandte Entomologie. - : Wiley. - 0044-2240. ; 99:1-5, s. 21-25
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Tidskriftsartikel (refereegranskat)abstract
- An experiment to investigate the dispersal and supposed reattack by parent spruce bark beetles, Ips typographus (L.), was performed. More than 20,000 parent beetles were marked with fluorescent powder and immediately released from platforms when they reemerged from trees attacked during the spring swarming. Thirty‐eight marked and over 8000 unmarked beetles were trapped on sticky traps covering 21.6 m2 and placed on 21 trees within 30 m from the platforms. It was estimated that less than 4% of the trapped beetles had reemerged from trees within the 30 m. Verbreitung von ausgeflogenen Fichtenborkenkäfern, Ips typographus L. (Col., Scolytidae). Ein Markierungs‐Wiederfang‐Experiment Es wurde ein Experiment zur Ausbreitung und des Wiederbefalls durch Altkäfer von Ips typographus nach Verlassen ihrer ersten Brut durchgeführt. Mehr als 20 000 Käfer wurden beim Schlüpfen abgefangen, mit Fluoreszenz‐Puder markiert und von zwei Plattformen in unmittelbarer Nähe der Schlüpforte freigelassen. 38 markierte und mehr als 8000 unmarkierte Käfer wurden an Leimfallen (zusammen 21,6 m2), befestigt an 21 Bäumen in maximaler Entfernung von 30 m von den zwei Plattformen, gefangen. Es wird geschätzt, daß weniger als 4% der gefangenen Käfer aus den in Plattformnähe (30 m) befindlichen Brutbäumen stammten. 1985 Blackwell Verlag GmbH
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| 3. |
- Anderbrant, O., et al.
(författare)
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Ecology of the Dutch elm disease vectors Scolytus laevis and S. scolytus ( Coleoptera : Scolytidae) in southern Sweden.
- 1987
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Ingår i: Journal of Applied Ecology. - : JSTOR. - 0021-8901. ; 24:2, s. 539-550
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Tidskriftsartikel (refereegranskat)abstract
- Two rings of pheromone-baited sticky traps surrounded the elm wood at 20-300m and 1-2km outside the forest edge. Most Scolytus were caught at sites in the inner ring near the forest; <1% of the total were caught in the outer ring. Emergence from logs and trap catches showed a first peak in July. Flight activity was recorded from the end of May to September for both species. A 2nd peak of activity was evident in August in 2 of 3yr for S. scolytus.-from Authors
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| 4. |
- Anderbrant, O., et al.
(författare)
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Intraspecific competition affecting parents and offspring in the bark beetle Ips typographus.
- 1985
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Ingår i: Oikos. - : JSTOR. - 0030-1299. ; 45:1, s. 89-98
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Tidskriftsartikel (refereegranskat)abstract
- Parents re-emerged sooner at higher densities but the total proportion that re-emerged was independent of density. Over 20 offspring per female were produced at the lowest density (0.5/100 cm2) but only 0.6 per female at the highest density (31/100 cm2). Offspring from the lowest density were about 50% heavier than those from the highest density and also the fat content increased with decreasing density. Females weighed less and contained less fat than males. Male offspring from lower densities produced larger amounts of the pheromone components cis-verbenol and 2-methyl-3-buten-2-ol than males from the higher densities. Offspring from the highest density produced about half as many progeny as those from the lowest densities, showing an effect of density acting over more than one generation. Density-induced variation of beetle 'quality' might be of importance in the population dynamics of bark beetles.-from Authors
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