Spatial and temporal variation of apple blossom weevil populations (Col., Curculionidae) with recommendations for sampling

Abstract

The variance in apple blossom weevil, Anthonomus pomorum L., populations was studied in two experimental orchards in Hungary. Over a 15 year period there were four peaks in abundance, at three to six year intervals. Blossom infestation was greatest in the six orchard rows closest to a mixed oak forest. Variance in percent blossoms infested was as great between adjacent branches as between branches on opposite sides of the tree. There was greater variance in infestation percent between adjacent trees than between clusters of trees in different parts of the orchard. There was a slight positive correlation (r = 0.18) between blossom density and the percent infested blossoms. A recommended sampling plan of three branches from ten trees would give a precision of ± 3 % infested blossoms with an error of 0.05. Sampling should be in a stratified random pattern with concentration of samples near the orchard edge, especially edges adjacent to forests. Zusammenfassung Untersuchungen über räumliche und zeitliche Variation von Apfelblütenstecher‐Populationen (Col., Curculionidae) und Empfehlungen für die stichprobenartige Probenahme In zwei ungarischen Versuchsgärten wurde die Variation von Apfelblütenstecher‐Populationen untersucht. In einem Zeitraum von 15 Jahren gab es vier Häufigkeitsspitzen, in drei‐ bis sechsjährigen Intervallen. Der Befall durch Anthonomus pomorum L. war in den sechs Obstbaumreihen, die einem Eichenmischbestand am nächsten standen, am höchsten. Der Unterschied zwischen dem prozentualen Anteil befallener Knospen war zwischen benachbarten Zweigen genauso groß wie zwischen Zweigen von entgegengesetzten Baumseiten. Der prozentuale Befallsunterschied zwischen benachbarten Bäumen war größer als zwischen Gruppen von Bäumen aus verschiedenen Teilen der Obstbaumplantage. Es konnte eine schwach positive Korrelation (r = 0.18) zwischen der Knospendichte und dem Knospenbefallsprozent festgestellt werden. Die empfohlene stichprobenartige Entnahme von drei Asten von zehn Bäumen bringt eine Genauigkeit von ± 3 % mit einem Fehler von 0,05. Die stichprobenartige Entnahme sollte nach einem zufällig gegliederten Muster erfolgen, wobei vor allem Bäume nahe dem Rand der Obstbaumplantagen und insbesondere solche, die an Wälder angrenzen, beprobt werden sollten.

Differential susceptibility and suitability of domestic and wild apple species for a florivorous weevil and its parasitoids

“…Branches that were evenly distributed over the treetop had been randomly selected and marked before bud burst (Brown et al. ).…”

“…It used to be a minor pest (Brown et al. ; Toepfer et al. ), but with the application of more selective instead of broad‐spectrum insecticides, populations can increase to damaging levels (Toepfer et al.…”

“…,b; Sipos and Marko ), predominantly in years with high population densities and/or low bud set (Brown et al. ; Blommers ; Mody et al. ).…”

Flight behavior of pre‐ and postdiapause apple blossom weevils in relation to ambient temperature

“…pomorum, the apple blossom weevil, is a univoltine herbivore occurring throughout Europe (Ctvrtecka & Zdarek, 1992). The new generation of adult weevils emerges in May and feeds on new foliage and/or young fruit of the host trees for some 6-8 weeks, and then seeks dormancy sites (Speyer, 1939;Brown et al, 1993) (hereafter referred to as prediapause phase). In all areas of the species' range, severe winters with freezing temperatures occur.…”

Landscapes, orchards, pesticides–Abundance of beetles (Coleoptera) in apple orchards along pesticide toxicity and landscape complexity gradients

“…Instead, their abundance and distribution was driven by pesticide use. Previous studies proved that forests adjacent to apple orchards provide overwintering habitats for A. pomorum, while the semi-open woody vegetation in the landscape around the orchards affects positively the abundance of P. oblongus (Bailey et al, 2010;Brown et al, 1993).…”