Insects in Row Crops
IPM Report #3 - Southwestern Corn Borer Continues to Increase
Southwestern Corn Borer
Pheromone trap catches for southwestern corn borer continue to increase in Craighead and Greene Counties this week, and have also hit high numbers in Poinsett, White, Woodruff and Jefferson Counties (highlighted in red on map above). As we stated in the last post, we recommend making an insecticide application when trap numbers reach this level of 100 moths per week per trap. Current trap captures can be seen on the Arkansas Row Crop Moth Trap website. Trap catches in the remainder of the state remain relatively low. Bt corn hybrids are very effective at controlling corn borers and do not need to be sprayed. Insecticides with a long residual containing either methoxyfenozide or chlorantraniliprole as the active ingredient are recommended (see table below). These insecticides will give about 3 weeks of protection against borers that have not already entered the stem. Once borers enter the stem, foliar insecticides will not control them. Consult the Field Corn section of MP 144 - Insecticide Recommendations for Arkansas (a mobile friendly version can be found here) and your local county extension office for control options for corn borers and other pests.
|
Insecticide |
Rate (oz/acre) |
REI (restricted entry interval) (hours) |
PHI (pre-harvest interval) (days) |
|
Besiege |
6 – 10 oz |
24 |
21 |
|
Elevest 2.22 SC |
5.6 – 9.6 oz |
12 |
30 |
|
Intrepid Edge |
4 – 12 oz |
4 |
28 |
|
Intrepid 2 F |
4 – 16 oz |
4 |
21 |
|
Vantacor 5 SC |
1.2 – 2.5 oz |
4 |
14 |
|
Shenzi 400 SC |
1.7 – 3.8 oz |
4 |
14 |
|
GCS Methoxy 2 F |
4 – 16 oz |
4 |
21 |
|
Invertid 2 F |
4 – 16 oz |
4 |
21 |
|
TurnStyle 2 F |
4 – 16 oz |
4 |
21 |
|
Vexer 2 F |
4 – 16 oz |
4 |
21 |
|
Inspirato 2 F |
4 – 16 oz |
4 |
21 |
|
Invicar 2 SC |
4 – 16 oz |
4 |
21 |
|
Thwartex 2 F |
4 – 16 oz |
4 |
21 |
|
Zylo 2 F |
4 – 16 oz |
4 |
21 |
Corn Leafhopper (Dalbulus maidis)
Corn leafhoppers are moving north and have been detected in southern Oklahoma. Counties in green in the map below show where the leafhopper has been found. There are no reports of this pest in Arkansas at this time. If it does show up, it is doubtful that it will be a problem except on very late planted corn. The current distribution of the leafhopper can be seen on the Corn Leafhopper Map on the Crop Protection Network website.
