Author Archives: Sean Malone

Corn earworm/bollworm update for August 26, 2021

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Captures of corn earworm (=bollworm) moths decreased this week in our black light traps. The average number of moths caught per night was: Dinwiddie = 2; Greensville = 6; Prince George-Templeton = 1; Prince George-Disputanta = 2; Suffolk = 13. Here is the Table. In our unsprayed, conventional (non-Bt) cotton plots at the Tidewater Agricultural Research and Extension Center in Suffolk, we had 11% boll injury due to bollworm feeding this week. Adult cypermethrin (pyrethroid insecticide) vial tests have 29% moth survival with 796 moths tested in 2021.

Corn earworm update for August 12, 2021

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Corn earworm (=bollworm) moth catches continued to increase this week in our black light traps. The average number of moths caught per night was: Greensville = 10; Prince George-Templeton = 26 (Scott Reiter reported this trap is next to some early April-planted corn that the shucks are starting to dry down on); Prince George-Disputanta = 6; Southampton = 10; Suffolk = 27. Here is the Table. We found bollworm eggs in cotton in Greensville and Suffolk this week. The 2021 season average in our adult cypermethrin vial tests is 25% survival (562 moths tested).

Corn earworm update for August 5, 2021

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Corn earworm (=bollworm) moth catches increased this week in our black light traps. The average number of moths caught per night was: Greensville = 7; Hanover = 11; Prince George-Templeton = 6; Prince George-Disputanta = 3; Suffolk = 22. Here is the Table. Thanks to our trap operators Sara Rutherford, Laura Maxey-Nay, Scott Reiter, Josh Holland, and Sally Taylor’s entomology crew.

In our adult vial tests this week (July 29-August 3), 43% of moths survived the 24-hour exposure to cypermethrin (a pyrethroid insecticide) at 5 micrograms per vial (n = 169 moths tested). The season average is 25% survival (446 moths tested).

Corn earworm moth report for July 29, 2021

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Black light trap captures of corn earworm moths (average number per night) in southeast Virginia this week were: Prince George-Templeton=0.7; Prince George-Disputanta=0.9; Southampton=2.0; Suffolk=4.0.

Our pyrethroid (cypermethrin @ 5 micrograms per vial rate) vial tests currently have 14% of corn earworm moths surviving the 24-hour exposure period (n=243 moths tested).

Corn earworm report–September 24, 2020

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Corn earworm moth black light trap catches were low this week, averaging from 2 to 6 per night (Greensville=3; Hanover=2; Southampton=6; Suffolk=2). Most trap operators will be shutting off their traps by the end of this month. We greatly appreciate the efforts of cooperating growers, Virginia Cooperative Extension Agents Mike Parrish, Sara Rutherford, Laura Maxey-Nay, Scott Reiter, and Josh Holland, and Tidewater Agricultural Research and Extension Center’s Daniel Espinosa. TABLE

Corn earworm report–Sep. 10, 2020

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Average nightly corn earworm/bollworm moth black light trap captures for this week were: Greensville=28; Prince George-Templeton=5.5; Prince George-Disputanta=7; Southampton=17; Suffolk=76. Here is the Table

For soybean, here is the tool that calculates the corn earworm larval threshold number based on user input values for sampling techinque (sweep net or beat cloth), cost of insecticide application, price of beans, and row width: threshold calculator

We have done 391 vial tests so far this season, with 35% of moths surviving the 24-hour exposure to the pyrethroid cypermethrin at the rate of 5 micrograms per vial.