Fruit IPM for 7/15/20

Stink Bugs Apples and Peaches: Brown Marmorated Stink Bug (BMSB) activity is starting to increase in spotty locations.

BMSB has many alternate hosts, and orchard populations always seem to be ‘local’. In some cases BMSB counts are up to 7 per trap in Gloucester County and  10-12 per trap in Morris County. Most of our traps in northern counties have been placed near apples, and these types of populations can be very problematic.  Most, but not all of the pyrethroid  and pyrethroid premixes have good activity for BMSB. See the 2020 NJ Tree Fruit Production Guide for a list of effective materials. These insects move from host to host and increase this movement into tree fruit later in the season. Where growers are using OFM mating disruption in peaches, then weekly border sprays for BMSB will help. In apples a 7 day program may be needed as trap captures increase.

Peach:

Oriental Fruit Moth (OFM): We are at the end of the second generation. All OFM materials have been applied statewide. No additional treatments are needed unless trap counts exceed 8 males per trap.

Apple:

Spotted Lanternfly (SLF): SLF nymphs are present in several orchards in northern Hunterdon and Warren Counties. One BMSB trap in an apple orchard in Hunterdon County also had 6 SLF nymphs. Any insecticides used for BMSB should also kill SLF nymphs, although it is unknown at this point, if these are going to be problematic in apples. High populations of adults just prior to harvest, may secrete enough honeydew to cause a sooty mold on fair to light skinned varieties.

Codling Moth (CM): Trap captures are very low statewide. However, control of the first generation has been problematic, with infested fruit present in a number of orchards. Growers should pay close attention to their CM trap captures. When male moths start to be captured, and especially when over 5 moths per trap, then insecticides need to be applied.  In some orchards there is up to 10% first generation damage.  Most larvae have left the infested fruit and are in the pupal stage now, and will emerge as adults over the next 2 weeks.

Rots : Rot symptoms are appearing on susceptible varieties particularly Honeycrisp and Empire. Most of what we are seeing is bitter rot with some white rot. These infections occurred during the spring, and symptoms are only now just appearing. Bitter rot infections will continue during wetting periods for the rest of the summer.  The QoIl premixes Merivon and Pristine are good rot materials with Merivon being the better of the two. Luna Sensation and Luna Tranquility are also rated as effective. Alternate with a Captan/Prophyt mix or Captan/Topsin. Topsin has some efficacy for white and black rots but is not effective against bitter rot.

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): This is still the main pest of concern. Bluecrop is being machine picked and SWD are starting to slow down for the mid-season varieties. Remember that the later the season gets, then the higher the population gets, thus increasing the chances for  fruit infestation.  Elliott and other later season varieties should stay on a 7 day program.

Aphids: Average aphid infestation levels remained at similar levels as during the previous 3 weeks. We had an average of 3.6% of terminals infested with colonies. Some fields did show higher infestation rates with 58% of lower shoots infested. With the increased incidence of scorch virus over the last 2 years, it is difficult to accept aphid populations staying the same over several weeks, and even increasing in some fields. It is very likely that  some of the higher populations are in fields where the insecticide is just not getting to the target site. The target site in most of these cases is the lower part of the bush where new canes are developing. Anything you can do to reduce aphid populations in these parts of the plants is to your advantage.

Putnam Scale: Scale infested fruit is still present but at very low levels. We will be putting out new crawler traps over the next week to monitor for the second generation. Growers who had fields with infested fruit should gear up to treat the second generation of crawlers. This should be in early August. More on this when we start seeing them.

By the Numbers: