Already a source of food and biofuel, University of Florida researchers report in a new study that corn plants can help sustain populations of small, flying insects known as gall midges in order to control twospotted spider mites.
Spider mites are hard-to-manage, major pests of hundreds of ornamental and vegetable crops.
In the study, which is published in the current issue of Crop Protection, the highly mobile midge could find spider mites from more than 23 feet away and controlled more than 81% of spider mites on green beans in a greenhouse test.
The corn provides a supply of non-pest mites to feed gall midges when spider mite populations run low.
This is known as a banker plant system since the corn plant stores, or “banks,” extra prey for midges. And by using the midge to control spider mites, the system reduces the need for pesticides. The system was tested on green beans but could be applied to different greenhouse-grown crops, such as tomatoes.
“Anything you can do to manage spider mites without using pesticides is going to be a major benefit,” said Lance Osborne, an entomologist with UF/IFAS and co-author of the study. Osborne is based at the Mid-Florida Research and Education Center in Apopka.
Spider mites quickly build resistance to pesticides and become nearly impossible to control, Osborne said.
Study co-authors include graduate assistant Yingfang Xiao, associate professor Jianjun Chen, lab technician Katherine Houben and research assistant Fabieli Irizarry — all with IFAS, and Cindy McKenzie, research entomologist with the USDA in Ft. Pierce. EPA, the USDA Floriculture and Nursery Research Initiative, and UF/IFAS funded the research.