NC State Extension

Stink Bug Thresholds

To use these thresholds, sample at least 100 plants in the field. Sample at different locations in all fields and more plants in larger fields. Stink bugs tend to be more prevalent in field edges. Use this to your advantage by sampling edges first. If stink bugs are absent, they are unlikely to be in the middle of the field. Conversely, if numbers are high in edges, be sure to sample the field middle.

The thresholds in the table below change across the growing season and are specific to certain plant parts for partial plant sampling. Note that stink bugs cannot damage corn from V6 until prior to tassel, when the primary and secondary ear begin to push out.

The partial plant sampling no treat column represents the number of stink bugs per 100 plants, and below, where you can be confident not to use an insecticide treatment. If it is clear that you will reach this number before 100 plants are sampled, stop sampling. The partial plant sampling treat column represents the number of stink bugs per 100 plants, and above, where you can be confident you should use an insecticide treatment. If you reach this number before 100 plants are sampled, stop sampling and treat. If you get a number between the partial plant sample no treat and treat numbers, use the partial plant sampling fixed threshold.

The partial plant sampling fixed threshold column can be used as a guide for numbers that fall in between the no treat and treat numbers. Using this threshold, do not treat below this number and treat at, or above, this number. Finally, do not convert these numbers into percentages. Those thresholds are in the next table.

Area for partial plant sample Area for partial plant sample Partial plant sampling no treat (stink bugs per 100 plants) Partial plant sampling fixed threshold Partial plant sampling treat (per 100 plants)
V1 to V6 Stalk below lowest green leaf 6 9 13
Two weeks before VT to VT Stalk at one leaf above & below primary ear 9 13 18
R1 to R4 Stalk at one leaf above & two leaves below primary ear 35 43 52

The thresholds in the table below can be used to make treatment decisions and are based on sampling the entire plant. Like the partial plant sampling thresholds above, they change across the growing season.

The no treat column represents the percent infested plants where you can be confident not to use an insecticide treatment. The treat column represents the percent infested plants where you can be confident that you should use an insecticide treatment. The fixed threshold column can be used as a guide to treat when numbers fall between the no treat and treat numbers. Using this threshold, do not treat below this number and treat at, or above, this number.

Growth stage No treat (% infested plants) Fixed threshold (% infested plants) Treat (% infested plants)
V1 to V6 6 8 11
Two weeks before VT to VT 16 21 26
R1 to R4 30 36 43
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