Sweet Corn
European corn borer (ECB) moths are now being captured in parts of the state. Numbers are low, and no map will appear in this edition. It remains to be seen whether this first flight will amount to much, but recent years’ catches give no reason to suspect that a large population will develop. Whorl corn is the primary target for egg laying, but as yet, scouts have reported no signs of feeding injury. In northern and central counties, corn plants are not large enough to support ECB larvae. We expect to encounter some level of feeding over the next 2 weeks.
Look for the characteristic “shot-hole” type of feeding (photo below at right) and consider treating when infested plants exceed 12% in a 50 plant sample. As plantings proceed to the pre-tassel stage, ECB larvae may be found in emerging tassels (see photo at left). It is a good idea to treat individual plantings as they move into the full tassel/first silk stage one time. This eliminates any ECB larvae that have emerged with the tassels as they begin to move down the stalk to re-enter near developing ears.
Useful insecticides for this particular application include synthetic 
pyrethroids (IRAC Grp 3), spinosyns (including OMRI approved Entrust) IRAC Grp 5), and diamides such as Coragen or Vantacor (IRAC Grp 28) or materials such as Besiege which include the active ingredient in Coragen. Synthetic pyrethroids alone should NOT be used for corn earworm (CEW) protection on silking corn. Control with these materials is very inconsistent.
The highest nightly trap catches of ECB for the week ending 5/25/22 are as follows:
| Califon 1 | Georgetown 1 | Pedricktown 1 |
| Crosswicks 1 | Hillsborough 1 | Sergeantsville 1 |
| Dayton 1 | Medford 1 | South Branch 1 |
| Downer 1 | Milltown 1 | Woodstown 1 |
Several corn earworm (CEW) moths were captured this past week. Although there is little impact from these moths, their presence is a reminder that we sometime get a low, early population that lingers into the silking period of our first sweet corn plantings. Be sure to access information from this publication in the upcoming weeks to determine how frequently you must treat silking sweet corn to protect it from CEW infestation.
The highest nightly blacklight trap catches of CEW for the week ending 5/25/22 are as follows:
| Allentown 1 | Crosswicks 1 | Matawan 1 |
| Califon 1 | Farmingdale |
The pheromone trap network for CEW is established in central and northern counties at this time.
The highest nightly pheromone trap catches of CEW for the week ending 5/25/22 are as follows:
| Dayton 2 | Georgetown 1 | Snyder Farm (Hunterdon Co.) |
| Farmingdale 1 | Oldwick 1 |
Cole Crops
Low numbers of imported cabbage
worm (ICW at left) continue in cole crop plantings in central and northern NJ, and adults are evident everywhere. With warmer temperatures on the way, these infestations should increase rapidly. Check 5 consecutive plants each in 10 random locations throughout the planting, paying particular attention to the innermost leaves where ICW often feed (see photo at lower right). Consider treating if caterpillars are found on 10% or more plants that are in the 0-9 true leaf stage. From 9-leaf to the early head stage (in broccoli, cauliflower, and cabbage) infestations up to 20% may be tolerated. Once heads begin to form, a 5% threshold should be observed to protect the marketable portion of 
the plant. For leafy greens such as collards and kale, 10% plants infested is the threshold throughout.
Diamondback moth larvae (DBM) are now appearing in scouted plantings. Remember that some populations of DBM are resistant to carbamate and synthetic pyrethroid insecticides. The lack of DBM control with these insecticides has been noted in NJ previously. It is important to distinguish between common cole crop pests for this reason. DBM larvae grow to a length of approximately 0.5”, and taper toward both ends (see photo at lower right). 
These caterpillars thrash violently when disturbed. ICW grow to a length of approximately 1.25” and are covered with short hairs. Some chemistries that specifically target caterpillar pests are effective against DBM as well as all other caterpillar pests of cole crops. These materials include (active ingredient – trade name (IRAC* code)):
Spinosad/Spinetoram – Entrust/ Radiant (5)
Chlorantraniliprole – Coragen (28)
Cyantraniliprole – Exirel (28)
The IRAC group 5 insecticide, Entrust, is OMRI approved for organic production. Insecticides based on the soil-inhabiting bacterium Bacilllus thuringiensis (B.t.) may also be effective on caterpillar pests of cole crops. Examples include Xentari and Javelin. Note: It is important to check fields approximately 24-48 hours after an insecticide application if DBM larvae were targeted. This pest has developed resistance to newer chemistries in the southern US, and is becoming increasingly difficult to control here. Live DBM larvae 24-48 hours post application is a sign that this pest may be resistant to the active ingredient most recently used.
Flea beetles remain very active in a number of plantings, and warmer days will accelerate injury. Signs of “shot-hole” in leaves of host crops are an indication that flea beetles are present, even if the pests are not visible due to cold/wet weather. These pests have a preference for the “hotter” flavored crops like arugula, mustard greens, and turnip greens. They also attack Tuscan or lacinato kale frequently. Plants may be protected with at-planting, soil-applied neo-nicotinoid insecticides (see the 2022/23 Commercial Vegetable Production Recommendations for products). An OMRI approved foliar material for flea beetle management is Pyganic. This product will provide knock-down of flea beetles, but may need to be applied frequently on preferred host crops.
Tomatoes
Field scouting of outdoor and high tunnel tomatoes has begun. Low level aphid populations (see photo at right) have been found in a few tunnels. With plants in the vegetative or early flower stages, it is often acceptable to allow natural predation and parasitism to take its course. Beneficial insects such as syrphid fly maggots, ladybird beetles and parasitic wasps will frequently limit the advance of these early aphid populations before the advent of fruit production, especially if sides are left up in tunnels. This is particularly true if broad spectrum insecticides are avoided at this time. If aphid populations persist into the early/enlarging fruit stage, and their droppings are accumulating on fruit, aphid specific insecticides may be advisable. 
Growers should check tomatoes at least weekly, and note the presence of spider mites or aphids. Mites in particular should be treated early, so that they do not build to a population that becomes difficult to manage. Consider treating if aphids are found on multiple sites in a 5-site sample, and fruit are beginning to develop.
Peppers
With ECB moth activity now increasing, growers should be looking for ECB egg masses (see photo at left) on the underside of pepper leaves. The larvae that hatch from these eggs will bore into the central stem of pepper plants in the absence of suitable fruit. This damage causes the tops of the plant to die, and eliminating the crown set of fruit in the process. Check 2 leaves per plant on 5 consecutive plants in 10 random locations. Consider treating if 2 or more leaves are found to have ECB larvae on the lower surface.
