The presence of corn ear worm moths in the blacklight traps have increased this week. Sarah Rutherford in Greensville (Jarratt) recorded an average of 13 moths per night; Scott Reiter in Prince George had 62 moths per night in Wells and 42 per night in Rosbicki; The Tidewater AREC entomology team recorded an average of 50 moths per night in Suffolk.
Category Archives: Insect
Corn earworm update for Aug. 2, 2023
Corn earworm moth catches are starting to pick up in our black light traps, but at this point are still fairly low. Sara Rutherford in Greensville (Jarratt) averaged 6.8 moths per night; Scott Reiter in Prince George had 3 per night in Templeton and 1.5 per night in Disputanta; the Tidewater AREC entomology team (Benjamin McManaway and Gwenyth Gregory) captured an average of 4.4 moths per night in Suffolk. Here is the Table
Pheromone trap catches of corn earworm moths in Suffolk increased this week–we are using these moths as part of our insecticide resistance monitoring program. So far we have tested 76 moths, with 17.6% surviving a 24-hour exposure to cypermethrin (a pyrethroid insecticide).
Cereal leaf beetle in Virginia: update for March 9, 2023
Cereal leaf beetle, a pest of small grains, overwinters as an adult.
When temperatures warm, adults migrate to small grains to lay eggs; eggs are yellow-orange in color, usually in the midvein of the leaf, and may be single or several eggs end-to-end.
I saw a few eggs at our research center field today (March 9), they were a bit darker (and stickier) than their normal color. A female may lay 50 eggs. Larvae have orange-yellow bodies with dark heads and legs, but often appear as shiny black due to the covering of mucus and fecal matter they have on their body (they look like small slugs).
Larval feeding strips leaves of phytosynthetic tissue and can cause reductions in grain quality and yield. A temperature-based model developed using Virginia and North Carolina data shows that peak egg lay occurs at approximately 182 degree-days (using January 1 as a biofix; a lower development threshold of 8℃, and an upper development threshold of 25℃). With our warm February 2023 temperatures, we hit an earlier-than-normal peak egg threshold in Suffolk, VA on March 3 (I used the Tidewater AREC WeatherSTEM as my temperature source). The larval peak follows the egg peak by an average of 17.5 days, which would be the third week of March for Suffolk. It is important to note that the model states that extremely hot or cold years may affect its accuracy. Dominic Reisig (Professor and Extension Specialist, North Carolina State University) posted that the Salisbury, NC egg peak was predicted to occur on March 5-11, but a cooler forecast may push back the larval peak to the last week of March. As of March 8, Warsaw, VA is at 123 degree-days for cereal leaf beetle and the Eastern Shore has accumulated 119 degree-days.
To scout for cereal leaf beetle, inspect 10 tillers (stems) in at least 10 different sites. If you are seeing mostly eggs, you should scout again in 5-7 days when some have hatched into small larvae. The eggs may be parasitized. Both Virginia and North Carolina recommend an economic threshold of 25 eggs + small larvae (total) per 100 tillers. At least half of that 25 should be larvae. An insecticide spray, if needed, should target the newly-hatched larvae. Please refer to pages 4-44 and 4-45 of the Virginia Cooperative Extension 2023 Field Crops Pest Management Guide for additional information and spray recommendations. Another useful resource is a Journal of Integrated Pest Management article by Philips et al. (2011), Fifty Years of Cereal Leaf Beetle in the U.S.: An Update on Its Biology, Management, and Current Research.
Corn earworm report for September 8, 2022
Corn earworm (=bollworm) moth captures from southeast Virginia black light traps this week were 5 per night at Templeton (Prince George Co.) and 4 per night at Disputanta (Prince George Co.); Suffolk numbers averaged 45 per night. Here is the Table. In our pyrethroid resistance monitoring tests, the seasonal average is at 33% survival (n=565 moths tested).
Corn earworm update for September 1, 2022
Corn earworm (=bollworm) moth captures from southeast Virginia black light traps this week were 7 per night at Templeton (Prince George Co.) and 9 per night at Disputanta (Prince George Co.); Suffolk numbers reached 60 per night. Here is the Table. In our pyrethroid resistance monitoring tests, the seasonal average is at 33% survival (n=502 moths tested).
Corn earworm/bollworm update for August 25, 2022
This week’s corn earworm (=bollworm) moth captures from local black light traps were: Sara Rutherford (Greensville ANR Agent) reported a nightly average of 20 moths; Scott Reiter (Prince George ANR Agent) had 8 per night at Templeton and 10 at Disputanta; the Spiers reported 5 per night in Dinwiddie; and we averaged 28 in Suffolk. Here is the Table. In our pyrethroid resistance monitoring tests, the seasonal average is at 30% survival (n=395 moths tested).
Corn earworm/bollworm update for August 11, 2022
This week’s corn earworm (=bollworm) moth captures from local black light traps were: Sara Rutherford (Greensville ANR Agent) reported a nightly average of 13 moths; Scott Reiter (Prince George ANR Agent) had 16 per night at Templeton and 19 at Disputanta; and we averaged 28 in Suffolk. Here is the Table. In our pyrethroid resistance monitoring tests, the seasonal average is at 39% survival (n=278 moths tested).
Corn earworm/bollworm update for August 4, 2022
Corn earworm (=bollworm) moth captures continued to increase this week in local black light traps. Sara Rutherford (Greensville ANR Agent) reported a nightly average of 21 moths; Scott Reiter (Prince George ANR Agent) had 11 per night at Templeton and 18 at Disputanta; and we averaged 48 in Suffolk. Here is the Table. In our pyrethroid resistance tests, 45% of moths are surviving the 24-hour pesticide exposure period (n=200 moths tested).
Corn earworm moth report for July 28, 2022
Corn earworm (=bollworm) moth captures have started to climb in local black light traps. Sara Rutherford (Greensville ANR Agent) reported a nightly average of 17.7 moths; Scott Reiter (Prince George ANR Agent) had 6.5 per night at Templeton and 10.3 at Disputanta; and we averaged 17.9 in Suffolk. Here is the Table. We have also started our corn earworm moth pyrethroid resistance monitoring program–this week we had 55% survival in vials containing 5 micrograms of the pyrethroid, cypermethrin (n=82 moths tested).
Corn earworm/bollworm update for August 26, 2021
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.