Original paper
Einfluß natürlicher Feinde auf die Populationsdynamik der Getreideblattläuse im Winterweizen Mittelhessens (Homoptera: Aphididae)
Storck-Weyhermüller, Sabine
Entomologia Generalis Volume 13 Number 3-4 (1988), p. 189 - 206
47 references
published: Sep 1, 1988
DOI: 10.1127/entom.gen/13/1988/189
ArtNo. ESP146001303005, Price: 19.80 €
Kurzfassung
Im Massenwechsel tierischer Schaderreger kommt den naturgegebenen Regulationsmechanismen eine wichtige Rolle zu. Neben Witterung, Landschaftsstruktur, Anbauweise und Bestandesführung der Kulturpflanzen beeinflussen natürliche Antagonisten den Populationsverlauf der Getreideblattläuse. Hierbei beruht die Bedeutung der natürlichen Feinde in erster Linie auf ihrer langfristigen Wirkung als Regulationsfaktoren von Schädlingspopulationen, aber auch ein Eingriff der Prädatoren und Parasiten in das aktuelle Massenwechsel-Geschehen ist möglich [Wetzel 1986].Ökologie und Lebensweise der 3 in Mitteleuropa am häufigsten auftretenden Getreideblattlaus- Arten, Sitobian avenae (Fabricius 1775) (Große Getreideblattlaus), Metopolophium dirhodum (Walker 1849) (Bleiche Getreideblattlaus) und Rhopalosiphum padi (Linnaeus 1758) (Hafer- oder Traubenkirschenlaus), sind sehr unterschiedlich, wobei die beiden ersten als Schädlinge deutlich stärker hervortreten.
Abstract
Pest populations are limited by a complex of factors, whereby natural antagonists may exert an important influence on the population dynamics of cereal aphids in different ways. During the investigation period 1984-1985, Sitobion avenae (Fabricius 1775) and Metapolophium dirhodum (Walker 1849) are common at all experimental sites in the area around Giessen. However, there are differences in their dominance depending on the site. The % of mummified and parasitized Aphididae is higher in 1984 than in 1985, due to climatic conditions. Among the predators caught in the yellow pan trap, the most numerous are adults of Syrphidae, whereas in catches in window traps adults of Cantharidae were more abundant. The differences in trap catches regarding the kinds of traps and the abundance of predators in the field are discussed. The abundance and appearance of various genera of aphid preying Syrphidae, Coccinellidae and Chrysopidae is influenced mainly by microclimate, vegetation and density of cereal aphids. Propylea quatuordecimpunctata (Linnaeus 1758) and Episyrphus balteatus (De Geer 1776) are the most important species among Coccinellidae and Syrphidae resp'y, Chrysoperla camea (Stephens 1835) is less abundant. Due to climatic factors the efficiency of predators is higher in 1985 than in 1984, based on the same ratio between predators and prey. Larvae of Syrphidae are of special importance. During the investigation period, predators preying specifically on cereal aphids are first of all responsible for the final collapse of the aphid populations. The quantification of 'efficiency thresholds' for predators and parasites based on the ratio between predators and pests or the rate of parasitation resp'y could be of great importance for integrated pest management systems.
Keywords
Cereal aphids • Sitobion avenae • Metopolophium dirhodum • predators • Coccinellidae • Syrphidae • Chrysopidae • Propylea quatuordecimpunctata • Episyrphus balteatus • population dynamics • predator prey ratio