Sweet Corn
European corn borer (ECB) moth catches have fallen to very low levels over the past week. Remaining activity is highest in Gloucester and Camden counties (see ECB map at left). Threshold (12%+) level larval infestations are declining now, as the last corn plantings to be exposed to ECB in the whorl now are entering the silk stage. Larval infestations should decline sharply until the second flight appears.
The highest nightly trap catches of ECB for the week ending 7/08/20 are as follows:
| Cinnaminson 1 | Georgetown 1 |
| Downer 1 | Long Valley 1 |
| Eldora 1 | New Egypt 1 |
| Elm 1 | Springdale 1 |
Fall armyworm (FAW) larvae have appeared in low numbers in fields in Cape May County, as well as in Hunterdon and
Morris counties. This pest seems to have arrived last week some time, and has since subsided somewhat. This is the time of the summer when FAW can show up, resulting in significant injury to whorl and even seedling stage corn. Injury from newly hatched larvae shows up as “window panes” or areas where leaf tissue has been eaten down the the lower epidermis (see photo at left). This injury leads down into the whorl. As larvae gain size, they begin to consume leaf tissue in its’ entirety, creating ragged holes and lots of droppings (see photo at right). FAW can be tough to manage because it is resistant to synthetic pyrethroid insecticides (IRAC 3A) and because larvae are often covered by their own droppings, making contact with the insecticide more difficult. Treat when 12% or more plants exhibit FAW injury alone, or in combination with ECB injury.
Corn earworm (CEW) moth captures have declined in blacklight traps this past week. Despite lower moth levels, silking corn continues to require protection from this pest. Blacklight catches remain highest overall along the coast (see map at left).
The highest nightly trap catches of CEW in black light traps for the week ending 7/08/20 are as follows:
| Matawan 2 | Medford 1 |
| Cinnaminson 1 | Milltown 1 |
| Downer 1 | New Egypt 1 |
| Farmingdale 1 | Sergeantsville 1 |
CEW pheromone trap catches declined, and continue to vary widely by region (see CEW pheromone map at left). Areas in white generally represent populations requiring 6-7 day spray schedules to manage, while blue areas are in the 5-6 day range. Green areas represent a 4-5 day schedule. The number of pheromone traps deployed is much lower, resulting in much broader color bands on the map. CEW activity in this network, however clearly indicates a highly variable but economically important population in the state at this time.
The highest nightly trap catches of CEW in pheromone traps for the week ending 7/08/20 are as follows:
| Woodstown 15 | Berlin 5 | Elm 3 |
| Crosswicks 9 | Folsom 4 | Allamuchy 2 |
| Beckett 8 | Pedricktown 4 | Dayton 2 |
| Monroeville 6 | Springdale 4 | Jones Island 2 |
Silking Spray Schedules*:
South – 4-5 days
Central – 5-6 days
North – 6-7 days
*These recommendations are based on regional catches. Adhere to tighter spray schedules if indicated by local trap catches. Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn, or for fall armyworm (FAW) management at any stage. Control with these materials is very inconsistent.
Pepper weevil
No weevils have been caught as yet. Traps are continuing to be deployed on farms in the area.
If anyone wants pheromone traps or participate in a project of evaluating different lures, please contact Joe Ingerson-Mahar, mahar@sebs.rutgers.edu; phone: 856-889-5718.
Pumpkins and Winter Squash
Note that Dr. Andy Wyenandt reports (Cucurbit Downy Mildew Update 7/06/20) that downy mildew (CDM) has been reported on cucumbers in Salem County. This is a clear indication that all growers of cucumbers and muskmelons should be scouting these crops every several days for signs of infection.
A cucurbit downy mildew sentinel plot has been established at Snyder Farm in Hunterdon County. This plot, consisting of pumpkin, watermelon, cantaloupe, butternut, acorn, cucumber and kabocha squash will be used to indicate the presence of cucurbit downy mildew in the region, and what crops are affected. As of 7/07/20, there was no CDM detected in this plot. For regional information on this important disease, see the Cucurbit Downy Mildew Forecast webpage: http://cdm.ipmpipe.org/. As of this Tuesday (7/7/20), New Jersey was listed as “moderate risk” for CDM.
Tomatoes
Tomato fruitworm (CEW) are still occasionally found in green fruit in high tunnel and field tomatoes in Hunterdon County, although infestation rates are well below 1% and no small (very recent) larvae have been detected. While this is typically a late summer occurrence, it is important that growers check plantings that have fruit present for infestation s of this pest. High tunnels do not offer protection from CEW or other caterpillar pests of tomato. CEW moths will lay eggs on the uppermost flower clusters. As these eggs hatch, larvae will bore into fruit in the upper and outer canopy (see photo at left). While infestations at this time may not result in significant fruit loss, actual losses are somewhat unpredictable. If tomato fruitworm infestations are found at 3 or more sites in a 10 site sample in the field, or in more than one site in a 5 site sample (as in a high tunnel), it may be time to apply an insecticide to limit further damage, especially if CEW moths are still being captured in local traps. A complete list of insecticides for this pest may be found in the Tomato Section of the Commercial Vegetable Production Recommendations. Note that the insecticide Entrust is OMRI approved. Avoid applying insecticides that carry a “M” or “H” designation for bee toxicity while bees are active in the field.
Two-spotted spider mites (TSSM) are becoming a more common occurrence in tomato fields now that warm weather has dominated for some time. These pests can build to high populations quickly and are a particular nuisance in high tunnels. Check two complete leaves each on 5 consecutive plants in 10 random locations in a planting. Look for the characteristic mite “stipple”, or whitish pin spots on the upper surface of the leaf (see photo at left). A check of the underside of the leaf should reveal the actual mites (photo at right). Be sure to take some samples from field or tunnel edges as this is often from where TSSM will enter the planting. Consider an miticide application if TSSM are found at more than one site in the sample. Miticide choices are found in the Tomato Section of the Commercial Vegetable Production Recommendations.
Brown Marmorated Stink Bug
Brown marmorated stink bugs (BMSB) have been coming to blacklight traps, and catches are generally heavier in southern New Jersey. While this pest has generally declined as a threat to peppers, it remains a significant threat to tree fruit.
The highest nightly catches of BMSB in black light traps for the week ending 7/08/20 are as follows:
| Downer 13 | Denville 3 | Centerton 2 |
| Tabernacle 5 | Green Creek 3 | Hackettstown 2 |
| Woodstown 4 | Springdale 3 | Hillsborough 2 |
| Crosswicks 3 | Allentown 2 | Georgetown 1 |
2020 Vegetable IPM Program Personnel
Kris Holmstrom and Joe Ingerson-Mahar would like to acknowledge the IPM Field Technicians for this season:
Allison Cormier
Patrick King
Kelly Landers
Kaitlin Quinn
James Rodgers
Without the assistance of these individuals, much of the information presented in this publication would be unobtainable. We are grateful for all their help and hard work.
