Impact of secondary parasitism on Aphidius colemani in the banker plant system on aphid control in commercial greenhouses in Kochi, Japan

Abstract

In order to elucidate the impact of secondary parasitism on a banker plant system, aphid parasitoids on banker plants were surveyed for four years in commercial greenhouses producing eggplant and sweet pepper in Kochi Prefecture, Japan. A banker plant system using Aphidius colemani was introduced into the greenhouses in November or December for the control of pest aphids from February through May. The mean rate of secondary parasitoids to total parasitoids on the alternative host aphid (Rhopalosiphum padi) on banker plants was less than 35% in the early season. In March or April, the mean rate exceeded 40%, and was more than 70% by May or June. Three main species of secondary parasitoids, Alloxysta sp. nr victrix, Dendrocerus laticeps and Syrphophagus sp., occurred throughout the season. In addition, Asaphes suspensus and Pachynouron aphidis occurred later in the season. In greenhouses where the banker plant system of aphid control failed, the increase of secondary parasitism on banker plants was sharper than in greenhouses with successful aphid control. In March and April, the higher rates of secondary parasitism on banker plants had a significant influence on the failure of aphid control.

Approaches to conserving natural enemy populations in greenhouse crops: current methods and future prospects

“…The types and use of different banker plant systems have been evaluated in two recent review papers: Frank (2010) and Huang et al (2011). These papers show that many banker plant systems have been developed, but only a limited number are currently applied due to a range of practical problems such as the risk of hyperparasitism of the parasitized aphids (Nagasaka et al 2010;Jacobson 2011). However, banker plant systems show enormous potential for conservation of released natural enemies, if the practical problems can be overcome.…”

“…For example, banker plants could be developed that specifically support aphid predatory midges by selecting aphids which are not suitable hosts for parasitoids. The negative effects of increased hyperparasitism through banker plants could then be prevented (Nagasaka et al 2010).…”

Comparative Studies on Development and Reproduction of Four Cereal Aphid Species Reared on Sorghum or Barley to Evaluate as Alternative Prey for Banker Plant System

“…Aphidius colemani Viereck Jacobson and Croft, 1998;Walters and Hardwick, 2000;Goh et al, 2001;van Driesche et al, 2008 Aphidoletes aphidimyza Rondani Hansen, 1983;Kuo-Sell, 1985, 1987Bennison and Corless 1993----2010 1998; Nagasaka et al, 2010Nagasaka et al, 20102010Chowdhury and Wardlaw, 1978Kim and Kim, 20042010Frank, 2010 Frank, SSϭ249.550,Fϭ3.827,pϭ0.0102,d.f.ϭ3,SSϭ174,747.74,Fϭ535.174,pϽ0.0001,d.f.ϭ9,SSϭ3,801.13,Fϭ3.880,pϭ0.0001,d.f.ϭ320,SSϭ 34,829.370 d.f.ϭ2,SSϭ8,456.592,Fϭ50.3766,pϽ0.0001,d.f.ϭ3,231 Fig. 3.…”

Host species-dependent and size-dependent ecological characteristics of Ephedrus nacheri (Hymenoptera: Braconidae)

“…The first is collapse of the banker-plant system because of an increase in secondary parasitoids (Nagasaka et al 2010a;van Steenis 1995). Techniques to prevent the occurrence of secondary parasitoids are currently lacking, so chemical pesticides are the only means of treating commercial greenhouses.…”