Reproductive performance and natural antagonists of univoltine population of Ips typographus (Coleoptera, Curculionidae, Scolytinae) at epidemic level: a study from Sumava Mountains, Central Europe
2012
Lukasova, K., Ceska Zemedelska Univ., Prague (Czech Republic). Katedra Ochrany Lesa a Myslivosti | Holusa, J., Ceska Zemedelska Univ., Prague (Czech Republic). Katedra Ochrany Lesa a Myslivosti | Grucmanova, S., Ceska Zemedelska Univ., Prague (Czech Republic). Katedra Ochrany Lesa a Myslivosti
Population of I. typographus was studied in one locality with small-scale and short-term outbreak distant from large-scale and long-term outbreak area by several hundred meters. In total, ten spruce trees infested by the spruce bark beetle were examined. Always four stripes of bark (sample area) with the length equal to half the circumference of the trunk and the width of approximately 0.5 m were analyzed. The local spruce bark beetle population was characterized by high population density (1.5+/-1.2 entry holes per square dm), low number of eggs per female, and short maternal galleries. Relatively low reproductive success (0.8 female offspring per one mother beetle, percentage of surviving individuals varied between 1 and 18 %). The parasitism rate of living developmental stages of spruce bark beetle by larval parasitoids averaged 14 %. The level of infestation by pathogens and endoparasitoids in maternal beetles from their galleries was low. It was probably a result of short-term outbreak during which response of parasitoids was delayed in time.
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