Vegetable Crops News

Predaceous Stinkbugs Can Suppress Colorado Potato Beetle

The spined soldier bug, Podisus maculiventris, and the twospotted stink bug, Perillus bioculatus, are predaceous stinkbugs that are common in the Midwest. The twospotted stinkbug feeds almost exclusively on Colorado potato beetle, whereas the spined soldier bug is more general in its feeding habits, often prefering caterpillars. However, the resident bugs are not numerous enough in the spring to provide control of Colorado potato beetle.

In field cage trials in Washington State, releases of 5 to 10 bugs per plant resulted in a 50 percent reduction of large populations of Colorado potato beetles. At Colorado potato beetle densities of about 100 per plant, each bug reduced the number of beetles by about 8.5 percent. Three predators per plant significantly reduced defoliation and increased yield 65 percent over untreated plants.

The twospotted stinkbugs seem to kill the Colorado potato beetles at an earlier stage than the spined soldier bugs, so that there is less damage to the potato foliage.

Researchers believe early releases of twospotted stinkbug could significantly reduce first generation Colorado potato beetle populations, although additional releases may be required for the second generation. Releases of these stinkbugs could be combined with other controls, such as Bacillus thuringiensis, other natural enemies, or physical controls in an integrated management scheme for Colorado potato beetle on potatoes.

New methods developed for rearing the twospotted stink bug may make it economically feasible to offer this insect commercially.

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