INFO-BUG

Crop Selected: Field Corn
Crop Development: Tassel or silk stage.
Pest Selected: European Corn Borer (ECB), Ostrinia nubilalis

Biology

ECB overwinter in late larval stage in corn stalks and other host plants. Larvae pupate in the spring and adult activity can be observed in the late spring. First brood ECB injury initially appears as shot hole injury in mid-whorl stage corn. Early larvae of the 1st brood can be found in the whorl until they reach the late larvae stage when they burrow into the stalks and pupate.

The summer ECB adult flight coincides with tassel, silk and ear development. Second brood ECB early larvae feed initially on foliage. Late instar larvae proceed to burrow into stalks and ears resulting in stalk breakage and ear drop.

Click to see

ECB adults ECB Larvae ECB frass from boring ECB larva in stalk

Assessment

Check 20 plants in each of 5 different areas of field. Pull at least 2 whorls of each set of 20 plants and inspect closely for presence of ECB larvae.

1st brood rescue treatment may be needed when 50% or more of stand is infested and larave are susceptible to treatment. Typical 1st brood infestation levels in Ohio average about 20%.

2nd brood rescue treatment is warranted when egg masses or early larvae are found on 50% or more of plants. Abundant activity of ECB adults along field edges indicates a need for inspection for egg masses or early larvae in corn.

Treatments are not effective once larvae have bored deep into plants and become out of reach from chemical treatment.

Control

Materials labeled for control of ECB include the following:

Ambush* @ 6.4 to 12.8 fl oz/A
Asana* XL @ 7.8 to 9.6 fl oz/A
Capture* 2EC @ 2.1 to 6.4 fl oz/A
Dipel 10G @ 5 to 10 lb/A & ES @ 1-1/2 to 2 1/2 pt/A
Furadan* 4F @ 1.5 to 2 pt/A
Javelin WG @ 1-1/2 lb/A
Ketch DF @ 1 to 2 lb/A
Lepinox wdg @ 1 to 2 lb/A
Lorsban 15G @ 5 to 6.5 lbs/A & 4E* [spray] @ 1-1/2 to 2 pt/A
Mustang* @ 2.9 to 4.3 fl oz/A
Penncap-M* [spray] @ 2 to 4 pt/A.
Pounce* 3.2EC @ 4 to 8 fl oz/A and 25 WP @ 6.4 to 12.8 oz/A
Pounce* 1.5 G @ 6.7 to 13.3 lb
Warrior* 1CS @ 2.56 to 3.84 fl oz/A

* Use is restricted to certified applicators.

Use of granules is preferred when larvae are in whorls. Spray formulations may be used to get early larvae on foliage.

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