Blacklight trap catch in Painter has revelealed very little insect activty this week. We are still not seeing the main flight of corn earworm, which is good news for our growers because we they’ve had enough to worry about with drought. The hot dry weather has caused some outbreaks of Spider mites in tomatoes and soybeans. Commercial tomato growers are having particular difficulties managing this pest even with some of the best miticide tools on the market for vegetables (Oberon, Portal, Acramite, and Agrimek). I’ve heard of some tomato fields receiving applications of all of these products on a 5 day rotation and they still have spider mites, particularly in the lower canopy. Some rain could really help.

The blacklight trap counts in Painter were very low this week with virtually no key moth pests caught, except for 1 European corn borer, and 20 brown stink bugs, which was a big drop for stink bug catch from the previous week.

One arthropod pest that has cause some issues lately is spider mites. This pest will often have outbreaks when the weather is hot and dry. Commercial tomato growers are managing this pest with Oberon, Acramite, and Agrimek primarily. Another very good new miticide labeled on vegetables is Portal available from Nichino America.
Relative to vegetables soybeans have very few highly effective miticides. Growers can suppress high populations with Dimethoate, Lorsban, or Warrior. However, repeated sprays of these products can also flare up spider mites because they destroy predatory mites. The following text was taken from the Virginia Tech Pest Management Guide for Field Crops:

Mite outbreaks usually are associated with hot, dry weather, which accelerates reproduction and development. During periods
of high humidity and field moisture, a fungal disease can reduce populations but high temperatures can nullify these effects.
Outbreaks also are associated with the application of certain insecticides that kill natural enemies and/or seem to make the soybean
plant more nutritionally suitable for mites.
Check weekly for mites, starting in early July through August, especially during a hot, dry season. Concentrate on the field
borders and look for the early signs of white stippling at the bases of the leaves. Do not confuse mite damage with dry weather
injury, mineral deficiencies, and herbicide injury. If feeding injury is evident, press the undersides of a few damaged leaves on
white paper to reveal any crushed mites. Determine the extent of the infestation and assess the level of injury by examining 20
to 30 plants in the infested area. Field infestations often show defoliated or injured plants at some localized point, with injury
becoming less evident and extending in a widening arc into the field.
If isolated spots of mite activity are confined to the perimeter of the field, spot-treatment using ground equipment is recommended
to prevent further spread of mites into the field. If the infestation is distributed throughout the interior of the field, treatment
of the entire field is suggested if live mites are numerous (20 to 30 per leaflet) and more than 50 percent of the plants show
stippling, yellowing, or defoliation over more than one-third of the leaves. If rains come, mite development and survival will
decrease but may not drop to economic levels if heavy populations are developing under high temperatures.

Some no-till cornfields on the Eastern Shore are experiencing pest pressure from stink bugs. These insects can impact yield up to 10%. For corn seedlings and early whorl stage before silking, small developing ears (½ – ¾ inches long) can be damaged by stink bug feeding resulting in malformed ear development. Treat corn if 10 percent or more of plants are infested with stink bugs at or shortly
before ear shoots appear (about V15). Do not
treat stink bug infestations once silking has begun.
Most pyrethroid insecticides (such as Karate, Warrior II, Baythroid XL, Hero, Brigade, Prolex, Tombstone, and the generic equivalents, etc..) are effective against stink bugs.

Insect Trap Counts for Eastern Shore – Week ending Aug 29.
In general, catches of 7 or more moths per week indicate an activity alert for scouting for that pest.
The Blacklight trap counts for this week were as follows: David Long (Cape
Charles) = 93 corn earworm (remaining high), 16 beet armyworm (small rise), 4 fall armyworm (low), 1 brown stink bugs, 6 green stink bugs (very low).
Blacklight trap – Mark Colson (Eastville) = 47 corn earworm (decrease), 10 beet armyworm (small rise), 1 Fall armyworn (low); 17 green stink bugs, 9 brown stink bugs (drop). Blacklight trap Painter = 26 corn earworm moths (mod. low), 22 green stink bugs (big drop), 2 brown stink bugs (drop).
******************************************Corn earworm Pheromone Traps (weekly
catch): Keller = 3; Tasley = 13 (rise); Modesttown = 56 (big rise); New Church = 2; Horntown = 42 (big rise); Eastville = 177 (high and rising); Machipongo =
54 (drop); Painter = 69 (rise); Guilford = 5(low). Beet armyworm Pheromone traps (weekly catch): Modestown = 3; New Church = 3; Horntown = 4; Machipongo =
91 (remaining high); Painter = 29 (rise). Fall armyworm pheromone traps (weekly
catch): Painter: 1; Newman – Eastville: 6; Hortntown: 4 (low everywhere) ****************************************************************************************Summary,
corn earworm moth remains active on the Eastern Shore and additional egg laying on crops is likely. As mentioned previously, trap catches of 7 or more moths per week indicate the need for intensive scouting of crops for the pests.
Tomatoes, cotton, soybeans, green beans, and lima beans are important susceptible host crops on the Eastern Shore. Beet armyworm remains active in the Machipongo location, but few moths appear to be found outside that area.
Stink bug catch appears to have dropped off, and not much activity has been seen in soybeans. Soybean aphids can be found on some soybeans on the Eastern Shore, particularly in Accomack County. These insects should probably not be the driving force behind spraying your soybeans. Targeting corn earworms after egg hatch and before pods harden is critical to maximizing yield loss from insects. Most pyrethroid insecticides will control corn earworm as well as the other pests including soybean aphids, stink bugs, grasshoppers, and other caterpillar pests with the exception of beet armyworm. Fortunately I’ve not heard of any beet armyworm outbreaks so far on the Eastern Shore this year.

The above-normal rainfall that we’ve had on the Eastern Shore has brought some pest problems to corn growers in Virginia.
Periods of cool wet weather after planting resulted in slow germination in many fields, which left seeds and seedlings more vulnerable to soil insect pests such as seedcorn maggot, white grubs, and wireworms. The longer the seed remains in the ground the greater the chance of it being discovered by the aforementioned soil pests. At this point, most corn has been planted and there isn’t anything a grower can do postplanting for these soil pests. The majority of corn was probably treated with an insecticide seed treatment such as Poncho or Cruiser, which undoubtedly helped improve stand in many fields this year.
Another problem that the spring rainfall brought was slugs in no-till fields. This is an age old problem, and the solution has not changed in decades. Dry weather will eliminate the slug problem. However, if seedlings are small (less than 3 leaves), and the slug infestation is heavy, economic damage can occur from this pest. Below is the recommendations taken from the Virginia Cooperative Extension Pest management Guide for Field Crops http://www.ext.vt.edu/pubs/pmg/fc/InsectsCorn.pdf
Slug, Snail Sampling/Decision Making
Slugs can become serious pests in no-till fields during spring periods of cool, wet weather. Fields with heavy layers of manure, crop refuse, or thick weed cover are at higher risk from slugs. Because slugs feed at night and hide during the day in the mulch and surface trash near the seedlings, they often are not suspected of being the cause of the shredded leaves on the young corn seedlings. Yet slugs can be found during the day by turning over clods of dirt and surface trash near the seedlings. It is suggested that samples be taken from the area around 5 plants in 10 locations of the field to determine the average number of slugs associated with each plant. Populations of 5 or more slugs around each plant at the spike through the 3rd-leaf stage may be economic, especially if injury is heavy, plant growth is slow, and cool, wet conditions prevail. During dry, warm weather, 10 or more slugs per plant may be tolerated. Also, corn seedlings that have reached the 3rd-leaf stage of growth generally are able to outgrow feeding damage by slugs.
Cultural practices which may help reduce slug populations include reduction in the use of manure, shift to conventional tillage practices for at least one season, and minimum tillage to reduce the amount of surface trash.
There is basically one registered product for control of slugs, and it works well – Metaldehyde (product = Deadline M-Ps, or Deadline Bullets)applied at 10.0-40.0 lb per acre. For best results, apply product in evening. Especially beneficial if applied following rain or watering. It should be noted that most corn-producing states are suggesting an application rate of 12 to 15 lb/A, if banded over or along side the row after the plants have emerged. Recent Delaware field trials indicate good results against slugs using 10 lb Deadline M-Ps/A broadcast with a cyclone spreader. Spreader must be calibrated to deliver at least 5 pellets/sq ft. Slugs generally stop feeding in 2-3 hours and die within 2-3 days.
Another potential spring pest problem in corn is armyworm infestations on seedlings or early-whorl stage plants. Armyworm is a common early season pest that can cause occasional losses in corn and should be monitored for in the spring. Infestations usually first develop in fields of small grains or in other grass cover crops. In conventional tillage systems, partially-grown larvae can migrate into corn fields from grassy waterways or wheat fields. Armyworms chew irregular holes on the edges of corn leaves. Damage is usually first noticeable around the field margins adjacent to these areas. The name armyworm derives from its behavior of migrating in large numbers into fields similar to invading armies. In no-till or reduced tillage systems, infestation may cover the entire field. In these systems, eggs may be laid on grasses within the field prior to planting and herbicides may force armyworms to feed on corn as the weeds or cover crop dies. Cool, wet, spring weather usually favors armyworm development. Armyworms overwinter as partially grown larvae in grasses or small grain fields. When warm spring temperatures return, armyworm feeding resumes. Armyworms may move onto corn during this period. Moths also begin flying in spring and deposit new eggs. Eggs are small, greenish-white, globular, and laid in clusters of 25 or more on the leaves of grasses.
True Armyworm Sampling/Decision Making (taken from the VCE Pest Management Guide Pub. No. 456-016).
No-till fields planted into a small grain cover crop, pastures, or weedy fields all have a high risk for armyworm infestation. Survey field edges where margins border small grains or large grassy areas and watch for damaged plants. If armyworm damage is seen, examine 20 plants at each of 5 locations within the field and record the percentage of damaged plants, the average size, and the severity of injury.
Armyworms usually migrate from small grains starting in late May. Spot treatments may be warranted if infestations are confined to small areas. Control for armyworms is recommended if 35 percent or more of the plants are infested and 50 percent or more defoliation is seen on the damaged plants, provided that larvae average less than 0.75 inch long. Worms greater than 1.25 inches in length usually have completed their feeding. A number of insecticide products provide effective control of true armyworm including: most pyrethroids such as Baythroid, permethrin, Asana XL, Mustang Max, Warrior/Karate, Hero, as well as other insecticides such as Lorsban, Lannate, Sevin, Pencap-M, and Bt products.