Ecological considerations for biological control of aphids in protected culture

Abstract

Several braconid and aphelinid parasitoids, midges, lacewings, and ladybird beetles are used to control aphids in greenhouses. Here, I review three topics as ecological bases for the biological control of aphids in a protected culture: the preliminary evaluation of biological control agents, natural enemy release strategies, and the effects of intraguild predation (IGP) on biological control. A comparison of several parasitoid species was conducted to select agents for the biological control of aphids; the intrinsic rate of natural increase was a useful criterion in the preliminary evaluation. To compare predators as biological control agents, the aphid‐killing rate must be considered as a critical criterion, rather than reproductive criteria. The banker plant system (open rearing system) is used as a release method for Aphidius colemani and other natural enemies of aphids. Continuous release of parasitoid adults, which is the important characteristic of this method, has a stabilizing effect on population fluctuation in the aphid–parasitoid system. Two species of natural enemies can be used to control aphids in greenhouses. When one parasitoid and one predator are used simultaneously in a greenhouse, IGP of the parasitoid by the predator can occur, but the effect of IGP is less important in greenhouses than in the field.

Why is Coccinella septempunctata so successful? (A point-of-view)

“…In contrast, recent glasshouse experiments indicated that H. axyridis complemented biocontrol of Macrosiphum euphorbiae by the parasitoid Aphelinus asychis (Snyder et al, 2004b) (2006) concluded from other outdoor experiments that IGP is often unimportant in the field and warn that the results of laboratory IGP experiments should be interpreted with caution. Yano's (2006) review suggests that IGP may be even less important to biological control in protected culture than in the field.…”

Seasonal climatic variations influence the efficacy of predatory mites used for control of western flower thrips in greenhouse ornamental crops

“…Entomopathogenic nemotades such as Steinernema feltiae (Nematoda: Steinernematidae) are a compatible and effective option for use with predatory mites to control WFT. Nematodes are a good option in a biological control strategy involving predatory mites, because they primarily attack the soil-dwelling pupal stage of WFT (Buitenhuis & Shipp, 2005;Ebssa et al, 2004;2006), leaving the larval stages for predatory mites. Emergence of adult WFT was significantly reduced when the predatory mite G. aculeifer was added to bean seedlings along with two species of entomopathogenic nematodes, than either mite or nematode treatment alone (Premachandra et al, 2003).…”

“…(Gerson & Weintraub, 2007;Heinz et al, 2004;Yano, 2006). However, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), commonly known as western flower thrips (WFT), is the most important insect pest of greenhouse ornamental production (Buitenhuis et al, 2007;Heinz et al, 2004).…”

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

“…Thus, growers are at risk of introducing natural enemies too late. In order to overcome this risk, introductions can be made by means of a banker plant system, or an open-rearing system (Hansen, 1983;van Lenteren and Woets, 1988;Yano, 2006). Prior to pest occurrence, banker plants serve as a reservoir of control agents in the greenhouse by providing them with an alternative, non-pest food source.…”