Population growth and persistence when prey is diminishing in single-species and two-species systems of the predatory mites Euseius finlandicus, Typhlodromus pyri and Kampimodromus aberrans

1998 ◽  
Vol 88 (3) ◽  
pp. 275-286 ◽  
Author(s):  
Peter Schausberger
Keyword(s):  
Population Growth ◽  
Single Species ◽  
Predatory Mites ◽  
Typhlodromus Pyri ◽  
Kampimodromus Aberrans ◽  
Euseius Finlandicus

scholarly journals Untersuchungen zum Vorkommen der Phytoseiidae (Acari: Mesostigmata) und Roten Spinne, Panonychus ulmi im Südtiroler Apfelanbau

2021 ◽  
Vol 2 ◽  
Author(s):  
Martin Parth ◽  
Stefanie Fischnaller ◽  
Manuel Messner ◽  
Manfred Wolf
Keyword(s):  
Typhlodromus Pyri ◽  
Panonychus Ulmi ◽  
Neoseiulus Californicus ◽  
Amblyseius Andersoni ◽  
Kampimodromus Aberrans ◽  
Euseius Finlandicus

Von 2014 bis 2017 wurden intensive Untersuchungen zum Raubmilbenvorkommen (Mesostigmata: Phytoseiidae) und Auftreten der Roten Spinne Panonychus ulmi (Prostigmata: Tetranychidae) in ausgewählten Apfelanalgen in Südtirol (Italien) angestellt. Die Populationsdichten der Milben wurden wiederholt an bis zu 50 Standorten im Etschtal und Vinschgau erhoben. In 27 Apfelanlagen wurde im Verlauf der Jahre 2015-2017 die Artenzusammensetzung blattbesiedelnder sowie an Aststrukturen überwinternder Raubmilben eingehend untersucht. Insgesamt wurden 5581 Raubmilben einer morphologischen Artbestimmung unterzogen. Sechs Phytoseiiden-Arten wurden nachgewiesen. Amblyseius andersoni (Chant 1957) konnte an allen Untersuchungstandorten gefunden werden und wies eine Individuendominanz von 80% auf. Ein permanentes Vorkommen von Typhlodromus pyri (Scheuten 1857) und Euseius finlandicus (Oudemans 1915) wurde an 18,5% bzw. 7,4% der Standorte festgestellt. Kampimodromus aberrans (Oudemans 1930), Paraseiulus talbii (Athias-Henriot 1960) und Typhlodromus bakeri (Garman 1948) wurden sporadisch nachgewiesen. Neoseiulus californicus (McGregor 1954) wurde erstmals am Apfel in Südtirol nachgewiesen. Der P. ulmi-Befall im Untersuchungsgebiet erwies sich, sofern gegeben, als äußerst gering. Eine wesentliche Zunahme der Populationsdichten von P. ulmi und eine diesbezügliche Schadwirkung wurden nicht festgestellt.

scholarly journals Occurrence of predatory mites of the Phytoseiidae family on apple-trees in integrated and ecological orchards

2008 ◽  
Vol 44 (No. 2) ◽  
pp. 57-60 ◽  
Author(s):  
J. Praslička ◽  
A. Barteková
Keyword(s):  
Predatory Mites ◽  
Typhlodromus Pyri ◽  
Apple Trees ◽  
Amblyseius Andersoni ◽  
Euseius Finlandicus

During the 2005–2007, we identified six species of predatory mites in the integrated and an ecological orchard: <I>Phytoseius echinus</I>, <I>Phytoseius macropilis</I>, <I>Euseius finlandicus</I>, <I>Typhlodromus pyri</I>, <I>Paraseiulus triporus</I> and <I>Amblyseius andersoni</I>. The species <I>Phytoseius echinus</I>, <I>Euseius finlandicus</I> and <I>Typhlodromus pyri</I> occurred in both orchards. <I>Phytoseius echinus</I> was dominant especially in the ecological orchard, where its abundance was almost 60% of the overall number of detected mites. The number of all predatory mites differed considerably in the orchards; there was a higher abundance in the ecological orchard. <I>Euseius finlandicus</I> abundance was 38.32% in the integrated orchard and almost 17.61% in the ecological orchard. <I>Typhlodromus pyri</I> abundance was 17.96% in the integrated orchard and 13.63% in the ecological orchard. <I>Paraseiulus triporus</I>, <I>Amblyseius andersoni</I> and <I>Phytoseius macropilis</I> were less abundant.

Population growth and density dependence

2019 ◽  
pp. 63-80
Author(s):  
Gary G. Mittelbach ◽  
Brian J. McGill
Keyword(s):  
Population Growth ◽  
Density Dependence ◽  
Growth Model ◽  
Species Interactions ◽  
Single Species ◽  
Positive Density ◽  
Allee Effects ◽  
Species Population ◽  
Exponential Growth Model ◽  
Single Species Population

This chapter reviews the basic mathematics of population growth as described by the exponential growth model and the logistic growth model. These simple models of population growth provide a foundation for the development of more complex models of species interactions covered in later chapters on predation, competition, and mutualism. The second half of the chapter examines the important topic of density-dependence and its role in population regulation. The preponderance of evidence for negative density-dependence in nature is reviewed, along with examples of positive density dependence (Allee effects). The study of density dependence in single-species populations leads naturally to the concept of community-level regulation, the idea that species richness or the total abundance of individuals in a community may be regulated just like abundance in a single-species population. The chapter concludes with a look at the evidence for community regulation in nature and a discussion of its importance.

DYNAMICS OF A NONAUTONOMOUS SYSTEM WITH IMPULSIVE OUTPUT

2008 ◽  
Vol 01 (02) ◽  
pp. 225-238 ◽  
Author(s):  
YUANSHUN TAN ◽  
FENGMEI TAO ◽  
LANSUN CHEN
Keyword(s):  
Population Growth ◽  
Growth Model ◽  
Single Species ◽  
Nonautonomous System ◽  
Nonautonomous Equation

In this paper, an impulsive exploitation of single species modelled by a general nonautonomous equation is considered. The persistence of the population can be obtained under sufficiently weak conditions and also be distinguished from conditions that cause extinction. These attributes resemble corresponding features of the related autonomous population growth model and improve the results of [6–8].

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