NIghtly black light trap captures of corn earworm (bollworm) moths rose sharply at most reporting stations this week.  Historically, this time of year is when we see our peak moth flight occur, which is followed by egg laying.  Mike Arrington (Tidewater AREC Entomology) found an average of 12 bollworm eggs per 100 bloom/bloom tags in Suffolk cotton, which is almost egg threshold (the Pest Management Guide defines the egg threshold as 15-20 eggs per 100 blooms or bloom tags for Bollgard cotton).  In peanut, a field near Stony Creek (Sussex Co.) had threshold numbers of corn earworm larvae (4 larvae per row foot when using a beat cloth).

Black light traps caught low to moderate numbers of brown marmorated stink bugs (BMSB) this week, ranging from zero in some locations, to over 5 per night at Warsaw.  BMSB findings from the statewide soybean survey are mentioned in my August 9th post.  Please see the attached pdf for the black light trap tables for both of these pest species:  blt_11_Aug_2016

Since last week, we have confirmed white sugarcane aphid, Melanaphis sacchari, in sorghum in two more Virginia counties–Hanover (through ANR Agent Laura Maxey) and Amelia (through ANR Agent Laura Siegle).  Dr. Maria Balota’s crew also found them at the Tidewater AREC in Suffolk.

With the assistance of Johnny Parker and two growers near the town of Franklin, VA, in the past week our Entomology crew was able to capture (via pheromone traps) and test 312 corn earworm (bollworm) moths in our adult vial tests.  41.4% of moths from Franklin survived the 24-hour exposure to the pyrethroid insecticide, cypermethrin.  These results are similar to what we are seeing in Suffolk, with a seasonal average of 39.7% of moths surviving the vial test (42.9% surviving in the last week alone).  The following line graph shows the Suffolk results in more detail.

Corn earworm moths are being caught in high numbers in pheromone traps at the Tidewater AREC in Suffolk and at a location near Franklin (Southampton Co.).  Janet Spencer also reported an uptick in the moths captured in her pheromone trap in Isle of Wight Co.  Black light trap catches of corn earworm moths are on the upswing.

Brown marmorated stink bug catches were 2.9 per night at the Eastern Virginia AREC in Warsaw, and zero at the Tidewater AREC in Suffolk.  Please see the attached pdf for detailed trap captures.  BLT_4_Aug_2016

We have confirmed white sugarcane aphid (Melanaphis sacchari) in sorghum in three more Virginia counties this week—Suffolk, Prince George, and Dinwiddie.  Scott Reiter, Prince George Co. ANR Agent, reported that his aphids came from fields that were below threshold levels and were found along the field edge–very similar to the aphids from Suffolk.  Mr. Reiter also had white sugarcane aphids submitted from a Sussex Co. sorghum field.  The Dinwiddie aphids were found at Ag Expo.  White sugarcane aphid has been found in all the blue and green-colored counties in the map below.

As Dr. Ames Herbert mentions in his July 25, 2016 blog, we are seeing a mixture of aphids in Virginia sorghum fields this season, but we should guide control decisions based on white sugarcane aphid (Melanaphis sacchari) numbers and product recommendations (I recommend re-reading Dr. Herbert’s advisory and viewing the aphid images that he attached back on July 25).  As Dr. Mike Brewer of Texas A&M mentioned to us earlier this week, corn leaf aphids (Rhopalosiphum maidis) are rarely worth concern–they are just good food for beneficial natural enemies!  The Tidewater AREC Entomology crew, Virginia Cooperative Extension Agents, and other Virginia Tech faculty and staff (e.g., Dr. Joseph Oakes) have been hunting for white sugarcane aphid.  We have confirmed it in Greensville (through ANR Agent Nikki Norton), Nottoway (through Jim Riddell, and ANR Agent Haley Norton), Southampton (via ANR Agent Livvy Preisser, and Mike Arrington at the Tidewater AREC), and Sussex (via Mike Arrington).  You may notice that last week I reported white sugarcane aphid in Dinwiddie–that has been removed for the time being, but ANR Agent Mike Parrish is following up on a lead as I am writing this report.  In some locations, we have found yellow sugarcane aphid (Sipha flava) along with the white sugarcane aphid.  I have indicated on the attached map where these have been reported, and also where we have scouted sorghum, but have not found any sugarcane aphids (to date).  Please keep up the scouting efforts in your sorghum fields!

Corn earworm (bollworm) moth captures in the black light traps are beginning to pick up in Suffolk, with a slight increase in Prince George Co., and low numbers still in Warsaw and Southampton Co.  Pheromone trap captures of corn earworm moths (the ones that go into our adult vial tests) really spiked this week in Suffolk; additionally, we caught nearly 100 moths in one night with 3 pheromone traps placed in a field just outside of Franklin in Southampton Co.  Brown marmorated stink bug catches have increased at Warsaw, with a few reported from Prince George Co., Southampton Co. and Suffolk.  Thanks to Livvy Preisser (Southampton Co. ANR Agent), Mary Beahm (Eastern Virginia AREC in Warsaw), Scott Reiter (Prince George ANR Agent), cooperating growers, and the Entomology crew at the Tidewater AREC in Suffolk for their reports this week.  The attached pdf contains more details on the black light trap captures this season.  BLT_28_Jul_2016

We have vial-tested 444 moths in 2016, with a mean of 38.5% surviving the 24-hour exposure to the pyrethroid insecticide cypermethrin at 5 micrograms.  These moths all were captured in Suffolk pheromone traps.  While we aren’t able to say where these moths originated (they are strong fliers and could have grown up locally or far away), survival rates this high serve as a reminder that  alternative (i.e., non-pyrethroid) chemistries may need consideration for corn earworm (bollworm) management, especially if heavy infestations develop.  We are working with Johnny Parker and some Southampton Co. growers to trap in an area reported to have high numbers of corn earworm moths near Franklin–results of the vial testing in that location will be available next week.