There are a host of strawberry plant pests that are a constant nuisance to the gardener who has planted strawberry plants in hopes of a bountiful strawberry harvest (see the Strawberry Plant page for the most common perpetrators). With studies showing that organic strawberry plants are better than conventionally-grown strawberry plants, there has been a shift away from using the highly toxic chemical pest control methods. One of the most maddening pests is the tarnished plant bug (TPB).
TPBs are the bane of farmers who grow small fruits and vegetables, including strawberry growers. The bugs are tremendously resilient. In an attempt to kill them off, farmers will often apply insecticides three to five times per year. All these insecticides may be necessary for commercial operations, but home gardeners may be able to avoid such measures (see here for 10 Reasons Why You Should Grow Your Own Strawberry Plants).
The most infuriating aspect of a TPB infestation is the damage done to strawberries. Tarnished plant bug nymphs will inject a growing strawberry seed with a toxin. At the point of injection, the strawberry fruit will stop developing. This will result in a “nubbin.” Nubbins are one of the common types of deformed strawberries where there is a seed-packed brown tip to the strawberry and a halted development of the flesh.
How to Kill Tarnished Plant Bugs
It isn't easy. As mentioned above, great quantities of insecticide are required to murder these monsters. The best plan of action is to keep them out of your garden in the first place. Sprinkling diatomaceous earth may help keep them at bay. Also, since TPBs thrive in alfalfa, avoid mowing alfalfa while your strawberry plants are blooming.
In the future there may be a fungal method of TPB control. The University of Vermont Entomology Laboratory is currently performing research on controlling the insects with fungi. Should they be successful in isolating a fungus that will kill tarnished plant bugs, the world will be a better place for strawberry gardeners.
Tarnished Plant Bugs & Strawberry Plants: Conclusion
TPBs are bad news. You and your strawberries will be much better off if you never see one. But, as prevalent as these pests are, you may have to deal with them at some point. So, be on your guard, examine your strawberry plants and strawberries carefully, and if you see any nubbins, you'll know why they are there.