Optimizing biological control of greenhouse pests with banker plant systems

Project Overview

Project Type: On-Farm Research
Funds awarded in 2010: $14,959.00
Projected End Date: 12/31/2012
Region: Southern
State: North Carolina
Principal Investigator:

Annual Reports


  • Additional Plants: ornamentals


  • Education and Training: extension, on-farm/ranch research
  • Pest Management: biological control, chemical control, integrated pest management

    Proposal abstract:

    Banker plant systems offer a solution to problems of effectiveness, economic cost, and compatibility associated with augmentative biological control. Banker plant systems consist of a non-crop plant that provides food for natural enemies in the form of pollen or a non-pest herbivore so natural enemies can survive and reproduce even when no pests are present. Therefore, natural enemies are ‘released’ from banker plants continuously at no expense to growers. By increasing survival and reproduction of natural enemies within the cropping system, banker plant systems are intended to provide preventative, long term, and economical suppression of arthropod pests (Frank 2009). Biological control of western flower thrips generally entails releasing the predatory bug, Orius insidiosus (hereafter Orius) which is generally more expensive than insecticides. Therefore, some growers attempt to manage thrips with ‘Black Pearl’ banker plants to support Orius populations. ‘Black Pearl’ pepper plants produce large amounts of pollen which is used as food by Orius. Since Orius successfully reproduce on a diet of pollen, ‘Black Pearl’ banker plants can sustain a reproducing population of Orius to attack pests when they enter the greenhouse. The pepper plants may also act as trap plants by attracting thrips which get eaten when they attempt to feed on the flowers. A barrier to adoption of biological control is that growers must manage multiple pests with complementary tactics including insecticides (Van Driesche and Heinz 2004). We address this in two ways. First, Orius is a generalist predator that will consume aphids, mites and other important pests. Therefore, although promoted as a tactic to manage thrips ‘Black Pearl’ banker plants should also suppress aphids. Second, if an insecticide application becomes necessary, banker plants hosting Orius adults, nymphs, and eggs, can be removed from the greenhouse. After a safe interval banker plants can be replaced to repopulate the greenhouse. The ‘Black Pearl’ banker plant system targeting thrips with Orius has been developed largely by growers. Articles about this system appear in industry publications such as Greenhouse Management & Production (Wainwright-Evans 2009). This indicates grower interest which will increase adoption of banker plants if they are economical and effective. However, no research has been conducted to improve and demonstrate the efficacy, economics, and compatibility of ‘Black Pearl’ banker plants in commercial greenhouses.

    Project objectives from proposal:

    1) Determine optimal ‘Black Pearl’ banker plant density by examining Orius dispersal and efficacy at different distances.

    2) Determine if biological control by Orius is more effective and economical with ‘Black Pearl’ banker plants than with augmentative releases.

    3) Determine the compatibility of biological control with insecticide using augmentative release or banker plants to maintain Orius populations.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.