Sweet Corn
European corn borer (ECB) catches are still low, but catches are beginning to occur in more locations now (see ECB map at left). This is an indication that the second flight is beginning. ECB feeding in NJ sweet corn plantings is nearly non-existent at this time, but will appear again within 1-2 weeks. Check 5 plants each in 10 random locations for a 50 plant sample. Look for “shot-hole” injury, and consider treating when the number of infested plants in a 50 plant sample exceeds 12%. As infested plants proceed to the pre-tassel stage, live larvae and damage may be found in the emerging tassels. Once plants hit full tassel, ECB larvae will move downward on the stalk and re-enter the plant near the area where ears are forming. This can result in direct injury to the ear. Growers should consider an insecticide application at the full tassel stage to target ECB larvae as they migrate downward. This application can eliminate larvae that have escaped any earlier insecticide applications.
The highest nightly ECB catches for the previous week are as follows:
| Denville 2 | Eldora 1 |
| Califon 1 | Jobstown 1 |
| Clinton 1 | Medford 1 |
| Crosswicks 1 | Phillipsburg 1 |
Corn earworm (CEW) moth catches have increased northward this past week, with higher catches in coastal areas of central NJ (see CEW map at left). These low-to-moderate catches are a threat to silking sweet corn. Virginia Extension is reporting large CEW catches at their Tidewater station in southeast VA. This is an indication of a large scale local moth emergence event. We should be on guard now for weather such as approaching frontal systems that may assist the movement of CEW adults to our area from points south. The major migratory influx of moths generally does not occur until after mid-August in NJ, but we have seen this happen as early as the first week of August.
The highest nightly CEW blacklight trap catches are as follows:
| Beckett 1 | Elm 1 | Matawan 1 |
| Cinnaminson 1 | Farmingdale 1 | Sergeantsville 1 |
| Crosswicks 1 | Folsom 1 | Springdale 1 |
| Denville 1 | Hackettstown 1 | Tabernacle 1 |
Southern NJ CEW pheromone trap catches remained stable this past week. This more conservative network is also indicating a similar threat level to last week (see CEW pheromone map below at right). There are relatively few pheromone traps deployed compared to the number of blacklight traps in the state, resulting in much broader color bands on the pheromone map.
At present, the highest nightly pheromone trap catches are as follows: 
| Elm 14 | Beckett 2 |
| Pole Tavern 11 | Pedricktown 2 |
| Green Creek 10 | Berlin 1 |
| East Vineland 5 | Jobstown 1 |
| Woodstown 3 |
Fall Armyworm
Fall armyworm (FAW) moth catches have increased somewhat in southern NJ pheromone traps, but infestations in NJ have not. Larval populations are being managed effectively with appropriate insecticides when the infestations are identified promptly. We should expect increased infestation in the near future. This pest favors smaller whorl stage plants, and will even infest seedling stage plants if
the population is high. Infestations have been identified throughout New Jersey. This pest is capable of serious injury to plants, and scouting should commence immediately on whorl corn throughout the southern half of the state. Look for plants with “window-pane” type feeding that leads from the outer leaf surface down into the whorl (see photo at left). As larvae grow, this damage will progress to obvious ragged holes, with lots of caterpillar droppings in the whorl. The larvae are tan and brown (see photo at right), with a conspicuous upside down “Y” on the head capsule. If FAW alone or in combination with ECB are found to infest 12% or more plants in the sample, consider an insecticide treatment. FAW do not respond well to synthetic pyrethroid insecticides. In general, IRAC Group 5 materials like Radiant or Entrust (OMRI approved) or IRAC Group 28 materials like Coragen (or those that contain Coragen as a component) work very well on FAW and other caterpillar pests.
Silking Spray Schedules*:
South – 4 days
Central – 4-5 days
North – 6 days
*These recommendations are based on regional catches. Adhere to tighter spray schedules if indicated by local trap catches.
Pepper Weevil Update
Two specimens need to be examined, but otherwise no weevils were trapped this past week. As far as known, there are no infested fields at this time.
Brown Marmorated Stink Bug
Blacklight trap catches of the brown marmorated stink bug (BMSB) increased slightly in the southern half of NJ this past week (see BMSB map at left). Many of our brown stinkbugs and BMSB are now in the adult stage and seeking hosts on which to feed and lay eggs. Scouting for stinkbugs in peppers requires stealth, as the bugs will retreat into the canopy if they perceive a threat. While scouting for other insects and diseases, approach each sample site slowly. Before disturbing the foliage to search for ECB eggs, aphids, etc., observe the upper canopy for the presence of stinkbugs. Often, they will bask on the upper leaves. If adults, nymphs or egg masses are found in 2 or more sites in a pepper planting, consider treating preventively to limit feeding injury to fruit. There are several insecticide options listed in the 2016-17 Commercial Vegetable Production Recommendations.
Pumpkins and Winter Squash
Squash bug egg masses and nymph groups are now appearing in pumpkin and winter squash plantings (see photo at left – eggs at far left). Squash bugs do not generally cause economic injury in these crops. They are capable of damaging seedlings, and thus newly emerging or transplanted cucurbit crops should be monitored for their presence, but as our pumpkins are hitting bush or vine-run stages at this time, there is little threat from these bugs. Adults look like elongated brown stinkbugs, while nymphs that are newly emerged from the copper-colored eggs are green with black legs. As the nymphs progress through two molts, they become ash gray in color.
Cucurbit downy mildew (CDM) is active on cucumber in NJ. Examination of the sentinel 
plot (see previous posts for explanation of these plots) at the Snyder Research and Extension Farm in Hunterdon County showed that the cucumber varieties ‘Straight 8’ and ‘sv3462’ are now infected. No other cucurbit crops in the plot were infected. The sentinel plots at Snyder Farm and RAREC are just two of a network of sentinel plots in the eastern half of North America that will contribute information to the CDM forecast (http://cdm.ipmpipe.org/). These plots are scouted weekly for the presence of CDM. If found, the disease is reported to NC State Univ., the organization managing the forecast. Affected crops are also identified. The purpose of this is to provide early warning to growers of these crops so that they may react proactively to the disease, and treat the appropriate crops. A this time, it is important for all cucurbit growers to check the above website at least weekly for updates on the movements of CDM in the eastern U.S. While the imminent threat appears to be confined to cucumber, infections on other crops such as musk melon and butternut squash have been reported in western PA. As of 7/24/17, the CDM forecast issued by NC State had NJ at high risk to develop infections from regional sources, and new 
infections may have resulted from rains that day. Cool, damp weather on Tuesday of this week will have provided good conditions for infections to develop. ALL cucurbit crops should be scouted for the presence of CDM, and all cucumber plantings should be treated preventively. CDM causes yellow lesions to develop on the upper leaf surface (see photo above at right). Lesions are confined within veins initially, but coalesce quickly to kill the entire leaf when moist conditions prevail. Beneath these lesions (lower leaf surface), dark gray spores will be produced (see lower photo at right). If discovered, please report any incidence of CDM to your county agent as soon as possible.
Powdery mildew (PM) infections are becoming more common now on pumpkins and winter squash. The appearance of PM is not related to weather, but rather the maturity and stress level of plants. This disease is not nearly as destructive as DM, but must be managed sufficiently to permit continued vine health. PM lesions first appear as circular clusters of conidia (spores) on the upper or lower surface of older leaves (see photo at left). PM typically appears as the earliest fruit are developing. The threshold for beginning the PM protectant fungicide program is the appearance of 2 leaves with lesions out of a sample of 100 older leaves. For a comprehensive list of useful fungicides and their use in rotation, see the Pumpkin and Winter Squash section of the 2016-17 Commercial Vegetable Recommendations Guide.
