INFO-BUG

Crop Selected: Soybean
Crop Development: Vegetative stages [pre-bloom]
Pest Selected: Japanese Beetle (JB), Popillia japonica

Biology

Adults of the Japanese beetle are shiny metallic greenish bronze with reddish wing covers, and nearly 1/2 inch in size.

The adults emerge from the soil in late June where they have passed most of the year in the grub stage.

The adults feed on soybean foliage and a wide range of other plants from late June to early September. As a result, the Japanese beetle ranks as one of the predominant pests of soybeans in Ohio. Adults found in soybeans tend to aggregate together. As a result, the foliar damage is spotty and often overestimated.

Click to see

Japanese beetle adult & damage to soybean leaf

Assessment

Decisions to apply a rescue treatment to control insect defoliators such as the Japanese beetle must be based on the total level of observed defoliation caused by the entire pest complex.

A rescue treatment is warranted when the level of defoliation exceeds the following:

- 40% prior to bloom
- 15% from bloom to pod-fill
- 25% after pod-fill to plant yellowing

| Click to see defoliation levels on leaves: |

Japanese beetle alone seldon causes damage beyond the threshold level, since distribution of the beetles tend to be aggregated and seldom cause heavy damage over the entire area of a field.

Control

Where Japanese beetle is contributing to excessive defoliation, the following chemicals are labeled for its control:

- Ambush* 6.4 to 12.8 oz/A
- Asana* XL @ 5.8 to 9.6 fl oz/A
- Malathion ULV @ 8 oz/A
- Mustang* @ 3.0 to 4.3 fl oz/A
- Penncap-M* @ 3 to 4 pt/A
- Pounce* 3.2EC @ 2 to 4 fl oz/A or 25WP @ 3.2 to 6.4 oz/A - Sevin XLR PLUS & 4F @ 1/2 to 1 qt/A and 80S @ 2/3 to 1-1/4 lb/A
- Warrior* 1CS @ 3.20 to 3.84 fl oz /A

* Use is restricted to certified applicators.

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