The Black Pearl Pepper Banker Plant for Biological Control of Thrips in Commercial Greenhouses

2010 Annual Report for GS10-089

Project Type: Graduate Student
Funds awarded in 2010: $9,959.00
Projected End Date: 12/31/2011
Grant Recipient: North Carolina State University
Region: Southern
State: North Carolina
Graduate Student:
Major Professor:
Dr. Steven Frank
North Carolina State University

The Black Pearl Pepper Banker Plant for Biological Control of Thrips in Commercial Greenhouses


Black Pearl Pepper banker plants benefit populations of Orius insidiosus by providing pollen and a suitable oviposition substrate. Greenhouse experiments demonstrated that Black Pearl Pepper plants with flowers had a higher adult and nymphal abundance than plants that did not have flowers. Laboratory experiments showed that adult female survival increased when pollen from Black Pearl Pepper flowers was added to their diet. Other experiments demonstrate that the addition of pollen to O. insidiosus’ diet does not decrease the level of adult predation. Future laboratory and greenhouse experiments will determine if banker plants can provide better thrips suppression than augmentation alone.

Objectives/Performance Targets

  1. The overall goal of this project is to develop a banker plant system as a sustainable, effective, and economical management strategy for thrips in greenhouses. To achieve this, the specific objectives are to: 1) Determine how ‘Black Pearl’ Pepper Banker Plants affect O. insidiosus abundance by measuring survival and reproduction when flowers, thrips, flowers and thrips or neither are present; 2) Determine optimum banker plant density by measuring dispersal of O. insidiosus and pest suppression observed at increasing distances from the banker plant; 3) Evaluate the efficacy and economics of biological control by O. insidiosus using ‘Black Pearl’ banker plants compared to conventional augmentative releases in commercial greenhouses.


  • Objective 1) - Completed two-treatment caged experiment demonstrating that O.insidiosus on Black Pearl Pepper banker plants with flowers have a higher abundance than O. insidiosus on Black Pearl Pepper banker plants without flowers. o Currently working on the 2x2 factorial experiment with treatments flower/no flower and thrips/no thrips. Projected completion date is June 13th. - Completed experiments demonstrating that pollen from the Black Pearl Pepper banker plant benefits O. insidiosus by increasing survival time of adults. - Currently working on laboratory experiments to show that development time of O. insidiousus is decreased with the addition of pollen from the Black Pearl Pepper banker plant. Projected completion date is June 1st. Objective 2) - Completed commercial greenhouse (120’x20’ greenhouses) experiments which surveyed pest abundance in three different treatments: control (no insecticide, no release of beneficial, no banker plants, augmentation (no insecticide, release of O. insidiosus, and no banker plant) and banker plant (no insecticide, release of O. insidiosus, and banker plants). - Completed laboratory experiments showing that the addition of pollen to the diet of O. insidiosus does not affect the predation rate of adult thrips. - Currently working on smaller caged experiments in which O. insidiosus abundance and pest abundance will be monitored on banker plants and within the ‘crop’. Objective 3) - Cost/benefit analysis will be completed after other two objective experiments are completed and after further information from Hoffman Nursery. Will compare the cost of their current IPM in their non-banker plant houses (which uses mostly insecticiedes) to the estimated cost of implementing and maintaining a biological control program with the Black Pearl Pepper banker plant and O. insidiosus.

Impacts and Contributions/Outcomes

From our experiments conducted at Hoffman Nursery, the growers were able to understand more about the Black Pearl Pepper banker plant system that they had already been working with without any scientific observation as to its efficacy. I have presented a poster at Hoffman Nursery during the tour of the Southern Nursery Association last fall. I have also presented to the Johnston Country Nurserymen Association with the outcome of my experiments at Hoffman Nursery as well as some other laboratory experiments and a general review of biological control of thrips. The goal of these activities is to increase grower awareness and understanding of banker plant systems and biological control. We hope to reach a wide variety of nursery and greenhouse growers and provide them with instruction and considerations when implementing banker plant systems in dynamic growing situations.