A Mechanical Release System for Predator Insects

Controlling the Colorado Potato Beetle

The Colorado Potato Beetle (CPB) is a serious pest for potatoes.  Both adults and larvae feed on foliage and may skeletonize the crop. 

Beetle populations are usually suppressed by insecticides on commercial farms.  However, the ability of the CPB to develop insecticide resistance makes it a challenging pest to manage.  The use of natural predators is a green alternative to chemical pesticides.

The spined soldier bug, Podisus maculiventris, is a generalist predator native to North America that attacks all CPB developmental stages without damaging the plants.  Field experiments have shown that Podisus can significantly suppress CPB in potato.  A major challenge to the use of these predators against the CPB is the high cost of manual distribution of predators in the field. 

Recently, a mechanical distributor of predators has been successfully designed and built by a research team at the Department of Soils and Agri-Food Engineering at Laval University.  They have been working for more than six years 6 years on the development of this apparatus.

The prototype distributor has been successfully operated by potato growers in the field.  Using this distributor, masses of predators are placed in small containers and mixed with a carrier material.  The containers are mechanically opened at different locations.  These locations are determined in advance following field monitoring visits to determine the populations of CPB (Khelifi and Da Ladurantaye, 2012). Although this mechanical distributor has been specifically designed to release Podisus in the field, it could also be used to release other insects to protect many other crops such as eggplant and strawberry.    

Podisus maculiventris reared at The Bug Factory has been used to test the predator distributor in the field. Podisus can be purchased as eggs and nymphs from The Bug Factory.  They are an excellent choice for controlling caterpillars.

December 2022