Fruit IPM for 6/23/20

Peach:

Oriental Fruit Moth: We are between generations 1 and 2, with the first insecticide applications having been just applied in southern counties, and in northern counties due by the weekend. The second application will be due the following week. See timings below:

Tarnished Plant Bugs and Other Catfacing Insects:  Catfacing insect pressure has begun to increase in southern counties where groundcover management is poor. In addition BMSB was noted in several southern orchards. Populations are very low but this demonstrates that adults are present in orchard environments.

Bacterial Spot and Cold Injury: Infected leaves and infected fruit have increased slightly since last week. Damage levels remain very low however inoculum may be building. Fruit injury from bacterial spot results in dark lesions that are often accompanied by gummosis. We are now at pit hardening, so the fruit has some resistance to infection.

Brown Rot: Maintain coverage with effective materials until pit hardening. Do not rely on sulfur alone unless a dry weather pattern develops.

Apple:

Codling Moth (CM): We are between generations 1 and 2 throughout the state, and pest pressure is very low in most orchards. Low pest pressure is indicated by pheromone trap captures that are below 5 male moths per trap. No insecticides are needed in these cases. Under “normal” circumstances the first treatments will be due in southern counties close to the middle of July. However, things are rarely normal, so until then we need to go by trap counts. There are several locations, mostly in northern counties where trap counts are in excess of 10 moths per trap. This indicates a prolonged first generation emergence and populations which still have to be treated. Make sure to rotate insecticide classes in these cases. The use the codling moth virus, Madex, is also useful, and can be used to supplement regular insecticide use. Also remember to cover the tops and insides of the trees where a lot of the codling moth activity is going on. So to sum it up: Use insecticide rotations, use the virus for added biological control, use frequent reapplications especially when thunderstorms wash off the cover, and penetrate the tree for good coverage.

Tufted Apple Budmoth (TABM): A biofix was set statewide on May 6. In southern counties, we are in the middle of insecticide timing for TABM, with the last treatments due June 25 – 26.. In northern counties, treatments were due on June 18 through June 22, and predicted for June 29- July 1.

Scouting Calendar Tree Fruit Southern Counties

The following table is intended as an aid for orchard scouting. It should not be used to time pesticide applications. Median dates for pest events and crop phenology are displayed. These dates are compiled from observations made since 1995 in Gloucester County. Events in northern New Jersey should occur 7-10 days later.

Tree  Fruit Trap Counts – Southern Counties

Tree  Fruit Trap Counts – Northern Counties

Blueberry:

Spotted Wing Drosophila (SWD): Trap averages have remained close to the same levels as seen last week, but activity has increased on some farm sites to over 30 flies per trap. This is the main insect target now through harvest. Both Duke and Bluecrop should be covered with regular protective sprays. The best insecticide choices include any pyrethroid (Asana, Brigade/Bifenture, Danitol, Mustang, Hero), Imidan, Delegate, Lannate, Malathion ,and Exirel and Verdepryn. Assail is no longer recommended at this time of year.

Blueberry Maggot: There are no trap captures as of this writing. Whether this is just a late emergence year or if populations are being suppressed by SWD sprays really makes no difference in your management decisions. As long as trap captures are “0”, your management for Canadian exports is made a lot easier.

Aphids: Average aphid infestation levels decreased over the past week, with infestation levels at 2.5% of terminals infested. Some colonies are increasing in density with more aphids in each colony. The highest infestation was 30% of lower shoots infested. Some aphid materials such as Actara and Movento can be effective for scale (see below), but these are not effective for SWD.

Putnam Scale: Scale crawlers are still active and have increased in their movement onto some fruit. Scale crawlers move out from the lower parts of the canes. With the fruit being close to the terminals, this is the last place they can go, so 1^st generation crawlers often settle on the fruit. These are visible as tiny red dots with a light brown to gray center. The remainder is reprinted from last week as a reminder: Growers should take note if any berries have scale on them (see Figure 1), and which fields they come from. There are practically no scale insecticides that also control SWD. The one exception is Diazinon, but that can be only used once per season and has a 7 day PHI. Coverage is also key, so ground applications are required for adequate scale crawler control. Since this insect has 2 generations per year, it is wiser to note the fields that will need treatments and plan on treating those fields in early August when the second generation crawlers are active.

Oriental Beetle (OB): Oriental Beetle emergence is well underway. Mating and reproduction is ongoing. For those growers who have not yet treated with Admire for this insect, and still wish to do so, Duke fields can be treated after harvest. Bluecrop fields are also in the ‘treat after harvest’ catagory if you are done by mid July. Elliott fields can be treated any time up to 7 days PHI and prior to mid-July.

By the Numbers:

Grapes:

Grapes just past full bloom in southern counties. Bloom sprays are critical for disease control. Targets at bloom include: Botrytis; Powdery Mildew; Downy Mildew; Black Rot; and Anthracnose. A helpful discussion of disease management at bloom can be found at the Penn State Wine & Grapes U. You can also find suggestions on Mizuho Nita’s grape blog, and in the Rutgers Grape Production Guide.

Grape Berry Moth (GRB): The biofix was set for 6/3 in southern counties. We need 810 DD₄₇ until egg start to hatch and ‘early timed’ (insect growth regulators and diamides) insecticides are applied. These materials include Intrepid, and the diamide and diamide premixes – Altacor, Exirel, Voliam Flexi, and Verdepryn. Other materials like Imidan, Sevin and the pyrethroids can be applied 2-3 days later. The projected timing for the ‘early applied’ materials is on or about July 2-3 in southern counties.

Spotted Lanternfly (SLF): Spotted Lanternfly eggs have hatched in most parts of the state and nymphs have been seen occasionally in our scouting, mostly in central and northern parts of the state. Populations are extremely low where seen, averaging less than one nymph per 4 vines. There are several vineyards in northern counties where counts were significantly higher. There are no treatment thresholds that have been developed for this insect. We do know that once an egg mass hatches in the vineyard, the nymphs can stay around for a while. Nymphs (Figure 1) go through 4 instars, and can leave at any time before becoming adults. There may be a prolonged period of time when, after the nymphs leave, there are no SLF in the vineyard until mid to late August. Then as the fall progresses, more SLF adults come in and feed. Penn State provisional guidelines suggest insecticide use if there are at least 15-20 nymphs per vine, or 5-10 adults per vine. Brigade, Actara, Scorpion, Danitol, malathion, and Mustang have been the materials of choice. Do not combine Danitol with Captan on grapes.

Figure 1. First instar SLF nymph on grape. (Photo – David Schmitt).