Insect update for Sep. 29, 2016

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The 2016 survey of Virginia soybean for brown marmorated stink bug (BMSB) and kudzu bug is now finished.  We would like to acknowledge the Virginia Soybean Board and the USDA/NIFA Extension Implementation Project for their funding support.  Since mid-July, scouts Ed Seymore, Jamie Hogue, and the Tidewater AREC entomology crew made 867 soybean field visits to 68 counties for this project.  Ed and Jamie traveled a combined 22,600 miles.  BMSB were found in 42 counties, with the highest populations coming from Bedford, Shenandoah, Rappahannock, and Orange Counties.  Please see the map for the BMSB densities.

BMSB_density_map_2016

Large numbers of green stink bug were reported in soybean in King George (11 greens per sample), Nelson (12), New Kent (10), Rappahannock (11), and Lunenburg (9); these beans were all in the R6 growth stage.  The threshold for R3-4 to R7 stages is 5 stink bugs per 15 sweeps.  Moderate green stink bug populations (approximately 3-5) were reported in most of the other counties surveyed this past week.  After R7 (beginning maturity),  the stink bug threshold is doubled.

Scouts reported less than one kudzu bug nymph per 15 sweeps this week.  Over the course of the season, kudzu bugs were found in soybean in 32 counties.  Here is the final kudzu bug map:

KB_map_29_Sep_2016We conducted 77 cypermethrin vial tests this week with 61% survival by corn earworm moths.  We plan to finish out the season with what we collect and test next week.  The seasonal average now stands at 43.1% survival.

AVT_29_Sep_2016Finally, our black light traps have been shut down for 2016.  The assistance of the participating Virginia Cooperative Extension Agents, growers, and Virginia Tech faculty and staff in this study is greatly appreciated.  Here are the final tables for this season:  BLT_29_Sep_2016

Registration is open for the Mid-Atlantic Crop Management School.

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CropSchool

November 15-17, 2016
Princess Royale Hotel in Ocean City, MD

Registration is open for the 22nd annual Mid-Atlantic Crop Management School. This year’s school will feature 2 ½ days of timely presentations in the areas of crop management, nutrient management, pest management, soil and water management, and climate. This year, the school will also feature the popular Crop School on Wheels field tour (limited to 50 participants). Nutrient management (VA, MD, DE, PA), pesticide, and certified crop adviser (CCA) credits will be available. Register early for the best selection of sessions.

The session schedule is online at: https://cdn.extension.udel.edu/wp-content/uploads/sites/12/2016/09/23151701/2016_CMS_Program_Final.pdf

Registration information is posted at: http://www.cvent.com/events/2016-crop-management-school/event-summary-bbd4a7d2717545af9770626ef761a930.aspx?tw=E3-C1-0B-14-32-A0-CB-AB-1C-D6-9A-06-46-74-20-5F.

Contact Amy Shober (ashober@udel.edu) or Jarrod Miller (jarrod@umd.edu) with questions about the school. We look forward to seeing you there.

The Mid-Atlantic Crop Management School is organized by Extension Specialists from Virginia, West Virginia, Delaware, and Maryland featuring speakers from across the nation.

BMSB and kudzu bug survey of soybean: Sep. 22, 2016 update

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Our soybean scouts detected brown marmorated stink bug (BMSB) in three new Virginia counties this week (Halifax, Greensville, and Brunswick).  They found soybean fields in the following counties at BMSB threshold (3-5 adults + medium to large nymphs per 2-minute visual count or per 15 sweeps):  Albemarle, Bedford, Fluvanna, Goochland, Greene, Orange, Rappahannock, and Shenandoah.  Please see the map for more details.

When monitoring, don’t forget about our native stink bug species–we have been seeing moderate to high numbers of green stink bugs in some fields.  The threshold for a normal mix of stink bug species (green, brown, and BMSB) is 5 in 15 sweeps.

BMSB_map_22_Sep_2016Kudzu bug numbers in soybean remain below threshold.

KB_map_22_Sep_2016

Insect pest update for Sep. 15, 2016

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Soybean–brown marmorated stink bug (BMSB):  Our scouts detected BMSB in two new counties this week–Charles City and Stafford.  Eight counties were at threshold (3-5 per 2-minute visual count along the field edge)–these are listed at the bottom of the map.

BMSB_map_15_Sep_2016Soybean–kudzu bug:  A range of zero to 5 kudzu bugs per 15 sweeps was reported this week.  While no counties were at threshold levels (15 kudzu bugs per 15 sweeps), the highest numbers were reported in Campbell (5), Appomattox (4), and Amelia (3 per 15 sweeps).

KB_map_15_Sep_2016

Sorghum–white sugarcane aphid, Melanaphis sacchari:  No new counties reported for this pest this week.  So far this season, it has been confirmed in the following Virginia counties:  Amelia, Bedford, Charles City, Dinwiddie, Franklin, Greensville, Hanover, Isle of Wight, New Kent, Nottoway, Prince George, Southampton, Suffolk, Surry, and Sussex.

Corn earworm/bollworm resistance monitoring:  Survival of moths in the vial tests remains high.  We evaluated 297 moths this week, with 40.5% survival to the 5 microgram/vial rate of cypermethrin.  Our seasonal average stands at 42.8% survival (n = 1,552  moths evaluated).

Black light trap report:  Some reporting stations had a small bump upwards in the number of corn earworm moths captured (Warsaw, Prince George, Essex); declines occurred in Suffolk and Southampton.  Very few BMSB were caught.  Please refer to the tables for more information.  BLT_15_Sep_2016

Peanut maturity progress in Suffolk, VA

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The peanut maturity progress from Sep 2nd and until now seems to be optimal. Images taken on Sep 2nd and Sep 12 for ‘Bailey’ (Bailey peanut maturity progress in Suffolk), and ‘Sullivan’ and ‘Wynne’ (Sullivan and Wynne peanut maturity progress in Suffolk) peanut cultivars are presented here. Bailey, regardless when was planted May 2nd or June 4th, seems to be ready to dig in 10 to 15 more days. In the past 10 days, Sullivan shows a substantial increase of black and brown pod content, however the pod color spread is highest for this cultivar. This suggests that Sullivan may have two main crops this year, which is not surprising given the drought stress experienced for most part of August. This situation always makes digging decisions difficult, but we will continue to watch the maturity progress for this cultivar and extend the search to other locations than Suffolk. None the less, location and individual field conditions have significant effects on maturity. Under the conditions of 2016, Wynne is behind Bailey and Sullivan maturity wise. The images of podblasted pods suggest that digging for Wynne is expected in 20 to 25 days from Sep 12.  Again,  determining maturity in each field individually is the best method for farmers to determine the optimum digging time. Podblasting clinics, such as the one on Sep 19 planned by the new Extension Agent in Southampton County VA, Ms. Livvy Preisser <livvy16@vt.edu>, should be attended rigorously by peanut growing farmers.

Update on Boxwood Blight in Virginia

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English boxwood defoliated by the boxwood blight pathogen following introduction of infected container plants on the patio. (Photo by A. Bordas)

English boxwood defoliated by the boxwood blight pathogen following introduction of infected container plants on the patio. (Photo by A. Bordas)

Recent outbreaks of boxwood blight, caused by the fungus Calonectria pseudonaviculata, are causing concern in Virginia. Boxwood blight can cause severe defoliation of susceptible boxwood, including English and American boxwood, and is of serious consequence to nursery growers, landscapers and homeowners. All diagnoses of boxwood blight in home landscapes made by the Virginia Tech Plant Disease Clinic since last fall are linked to new boxwood purchased from several Virginia locations of one national retailer, and new cases are likely to emerge. (See news article at: http://www.newsadvance.com/news/local/boxwood-blight-hits-lynchburg/article_a2860e97-438c-523a-9c63-202902eaf42b.html).

We strongly recommend that growers purchase boxwood from a nursery or retail outlet that has purchased boxwood exclusively from a boxwood producer in the Boxwood Blight Cleanliness Program (http://www.vdacs.virginia.gov/plant-industry-services-boxwood-blight.shtml). These producers follow stringent practices to avoid the introduction of this disease to their nurseries and are subject to followup inspections by the Virginia Department of Agriculture and Consumer Services.

Black streaking on green stems of boxwood plant with boxwood blight.

Black streaking on green stems of boxwood plant with boxwood blight. (Photo by A. Bordas)

Symptoms of boxwood blight include leaf spots, black streaking on stems and severe defoliation. Other diseases of boxwood, such as Volutella blight and root diseases, can be confused with boxwood blight; therefore, laboratory confirmation is necessary. Learn to recognize symptoms of boxwood blight by viewing the image gallery on the Virginia Boxwood Blight Task Force web site (http://www.ext.vt.edu/topics/agriculture/commercial-horticulture/boxwood-blight/). Information on best management practices, resistant boxwood cultivars, and sanitizers for cleaning tools is also available on the web site.

In all the cases of boxwood blight diagnosed by the VT Plant Disease Clinic in home landscapes, the disease was introduced on infected boxwood plants. The fungus has sticky spores and is not adapted for movement on air currents; however, spores may stick to and be transported by spray hoses, tools, clothing, shoes, and vehicles. The fungus can also be transported in soil and likely by animals moving through infected plants, e.g. deer, dogs. Infected boxwood may also be present in holiday greenery.

If you suspect boxwood blight, collect symptomatic branch samples with at least a few green leaves still attached. Double bag the samples in sealable bags and take them to your local Virginia Cooperative Extension office (http://www.ext.vt.edu/offices/index.html). Samples will be forwarded to the Virginia Tech Plant Clinic for diagnosis.

Insect pest update for Sep. 8, 2016

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White sugarcane aphid, Melanaphis sacchari, in sorghum:  I did not receive any reports of this aphid being found in any new Virginia counties this week.

Brown marmorated stink bug in soybean:  Our scouts reported 11 Virginia counties having threshold levels of BMSB, with highest numbers from Bedford and Orange (9 and 6 BMSB per 2-minute visual inspection, respectively).  First reports for the season came from James City, King George, Culpeper, and Frederick.  Please see the following map:

BMSB_map_6_Sep_2016Kudzu bug in soybean:  Our scouts have not found any Virginia counties with threshold levels of this pest in 2016.  The current map:

KB_map_6_Sep_2016Corn earworm/bollworm (Helicoverpa zea) resistance monitoring:  The number of moths surviving the 24-hour exposure to 5 micrograms of cypermethrin in this week’s vial tests was 45.8% (n = 180 moths evaluated).  The seasonal average is 43.4% survival, based on 1,255 moths tested. AVT_7_Sep_2016Black light trap counts:  Corn earworm moth captures dropped slightly from the previous weeks’ counts; brown marmorated stink bug counts were zero across all reporting stations.  Please see the attached tables (pdf document) for more details:  BLT_8_Sep_2016

 

Heat Units (HU) accumulation and predicted vs. observed optimum maturity in Suffolk, VA

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September began and farmers may start planning for harvest. With peanut this is not an easy task. Days from planting and HU accumulation are usually used to determine a general harvest time; but fine tuning optimum maturity for individual cultivars, planting dates, and fields is absolutely necessary to minimize yield loss that may result from either rushed or delayed digging.  The table below shows the predicted digging dates based on HU from planting through end of August for Suffolk, VA, and comments on their suitability for estimating actual maturity (Digging Peanut in Virginia-Bailey) (Peanut maturity in VA), which was determined through pod blasting on Sep 2nd.

Based on observed maturity at this time, using solely HU accumulation may result in rushed digging this year.

Planting date HU accumulated through Aug. 31 Predicted days remaining Predicted date Predicted vs. observed maturity
15-May 2324 12 12-Sep Observed maturation through pod blasting shows later maturation than predicted by at least a week for all planting dates
25-May 2271 14 14-Sep
5-June 2058 24 24-Sep

Estimates are based on 2590 GDD required for Bailey to reach optimum maturity and a 22 daily average GDD from Sep 1 through Sep 24.

We will continue to update farmers on peanut maturity in SE Virginia, and encourage Extension Agents to organize pod blasting clinics by mid-Sep in every county.