Greenhouse - Banker Pepper Plants and Pirate Bugs for Thrips Control

Using banker plants to attact thrips and then using thrips predators to control them is a technique that is being used in some greenhouses as an alternative to chemicals and where insectide resistance has developed in thrips populations. The following is information on using minute pirate bugs for thrips control.

A biological control technique for thrips control in the greenhouse involves releasing the predaceous minute pirate bug, Orius insidious, on dwarf pepper plants like ‘Black Pearl’. One pepper plant covers around 1,000 ft2 of growing area. Plant them in 6” pots in November or early December. The plants need to be growing for about 2 months before you start your spring bedding plants. With high energy costs this may be later than normal in 2009, so once you establish a start date for your spring crop then determine the when to get the pepper plants started. Release 60 - 80 minute pirate bugs per pepper plant. ‘Black Pearl’ Pepper They will lay eggs in the same area where thrips lay eggs, usually in or near flowers. Pepper plants are magnets for thrips, and serve as banker plants and indicator plants for early detection. As long as the pepper plants are in flower and producing pollen, the minute pirate bugs will reproduce on the banker plants. The adults will fan out across the greenhouse and kill 1st and 2nd instar thrips larvae and adult thrips. The good news is that only one release of minute pirate bugs onto the banker plants is necessary. To give you an idea of cost, 500 minute pirate bugs would be around $50 - $60.

Information from the October 10, 2008 edition of the Greenhouse TPM/IPM Weekly Report from the University of Maryland Cooperative Extension, Central Maryland Research and Education Center.