Last year, the insecticide Exirel® (FMC Corporation) was registered for use in cranberries. The Exirel label includes the target pests: cherry fruitworm, cranberry fruitworm, blackheaded fireworm, and Sparganothis fruitworm. The active ingredient (a.i.) is cyantraniliprole. This insecticide belongs to a class of insecticides known as anthranilic diamides (similar to Altacor). This class of insecticides is particularly effective against lepidopteran pests but Exirel has broader insecticidal activity that includes flies, aphids, weevils, etc. After ingestion, anthranilic diamides work by impairing muscle contraction, resulting in feeding cessation, lethargy, and partial paralysis, eventually leading to the death of the insect.

Exirel is considered a reduced-risk insecticide and compatible with biological control and pollination. It should thus be considered as a new alternative when rotating insecticides with different modes of action for preventing the development of resistant populations.

Exirel has a 14-day pre-harvest interval (PHI) and a 12-hour re-entry interval (REI). A maximum of 0.4 lb a.i. can be applied per acre, which equates to three applications at the highest label rate (20.5 fl oz per acre).

Our previous work in laboratory and semi-field experiments has demonstrated that Exirel can provide similar, or sometimes even better, larval control as compared with other registered materials such as Intreprid, Delegate, and Altacor. I encourage growers to consider using Exirel as a pre- or post-bloom application for the control of lepidopteran pests. Because it is a new insecticide, we have limited (large-scale) field data, so I recommend growers to start by using Exirel in a few acreages and share their experiences with me.

The following insect pests bear special mention for early-season scouting in cranberry bogs:

Blackheaded fireworm – Blackheaded fireworm eggs overwinter on the bed and usually hatch by around mid-May. It is important to catch the first generation, if possible, because the second generation occurs during bloom and is typically much more destructive. Blackheaded fireworm larvae can be detected by sweep net sampling and it is a good idea to look along the edges of beds where vines first begin to grow. Remember: blackheaded fireworm is much easier to control if detected during the early part of the season.

Spotted fireworm – This insect overwinters as a 2nd instar larva. They complete two generations a year. Larvae feed between uprights they have webbed together. First-generation larvae injure the foliage causing it to turn brown as if burned. In New Jersey, first generation adult moths emerge the first week of June, followed by a second-generation of adult emergence in early August. Eggs are laid in masses on weedy hosts. Larvae from second-generation adults emerge in mid-August, and may feed on fruit. Populations of spotted fireworm are regulated by their natural enemies, in particular Trichogramma wasps that parasitize the eggs.

Sparganothis fruitworm – This insect is a serious pest in most cranber

ry-growing states. Sparganothis fruitworm completes two generations a year and overwinters as an early-instar larva. Larvae from the 1st generation feed on foliage. In New Jersey, first generation adult moths emerge from mid-June through the first weeks in July; pheromone traps are commonly used to monitor adult flight and population size. Second-generation eggs are laid on cranberry leaves, and larvae will feed on fruit.

Cranberry blossomworm – Adults lay their eggs in October in cranberry beds. The eggs overwinter and hatch over a period of several weeks. Early instars can be found during the first week of May. Larvae go through 6 instars to complete development.

Because the first instars feed during the day (and also at night), scouting can be done during the

daytime using sweep nets to estimate larval abundance. Larvae turn nocturnal during the later instars. At this time, night sweeping (9 pm – 1 am) is recommended for sampling. Larvae complete their development by June-July. Older instars are very voracious and capable of destroying 100 blossoms within a 3-week period. There is a pre-pupal that lasts until the end of August and a pupal stage that lasts until October. Adults emerge from end of August to end of October.

Lepidopteran Pests Monitoring and

Control – Use sweep netting for monitoring early lepidopteran pests (pre-bloom). A sweep set consists of 25 sweeps and 1 sweep set is recommended per acre (this may vary depending the size of bogs). The action threshold for false armyworm, blossomworm, other cutworms, and gypsy moth (we use a combined threshold from adding all these caterpillars per sweep) is an average of 4.5 caterpillars in sets of 25 sweeps. For brown and green spanworms is an average of 18 per sweep set. The action threshold for blackheaded fireworm and Sparganothis fruitworm is an average of 1 to 2 per sweep set. We recommend the use of the reduced-risk materials Intrepid, Delegate, Altacor or Exirel if populations exceed action thresholds. Exirel is a newly-registered insecticide in cranberries. These are reduced-risk, softer insecticides that are very effective against lepidopteran pests. More information on these (and other) lepidopteran pests will be provided as the season progresses.

Leafhoppers –There is concern among New Jersey cranberry growers of a potential increase in leafhopper populations because of recent changes in pest management strategies (e.g., adoption of new reduced-risk products and decreased applications of broad-spectrum insecticides). Blunt-nosed leafhopper is of particular concern because

they can transmit cranberry false blossom disease. This leafhopper has one generation a year. Adults are found in highest numbers during July, although nymphs or adults may be found from the end of May until October. Eggs are laid in August-September. The eggs overwinter and hatch in May or June. The nymphs go through 5 instars to complete development.

Leafhopper Monitoring and Control: Leafhopper nymphs can be sampled using sweep nets (as described above for lepidopteran pests). Nymphs before bloom are small; thus, you may need to freeze the samples (to kill them), and then count the number of nymphs under a microscope or using a magnifying lens. There is no threshold based on sweep net counts, so decisions should be made based by comparing current numbers with prior infestation history and/or incidence of false blossom disease on those beds.
In cases of high numbers of blunt-nosed leafhopper nymphs, we recommend application of a broad-spectrum insecticide, such as Diazinon (no aerial applications allowed) or Lorsban (only pre-bloom applications allowed for Ocean Spray growers). Broad-

spectrum insecticides will disrupt biological control particularly the natural enemies (predators and parasitoids) of Sparganothis fruitworm, so their use should be restricted only to areas of high leafhopper populations.

Date: Thursday, January 23, 2020
Location: Rutgers EcoComplex, Bordentown, NJ

Agenda

8:00-8:30 Registration and Coffee

8:30-8:50 Welcoming remarks– Shawn Cutts, President, ACGA
Treasurer’s report – Shawn Cutts

8:50-9:10 Cranberry statistics
Bruce Eklund, National Agricultural Statistics Service, Trenton, NJ

9:10-9:35 Traits we have found in cranberry
Nicholi Vorsa, Professor, Department of Plant Biology, Rutgers University; Jennifer Johnson-Cicalese, P.E. Marucci Center, Chatsworth, NJ; and James Polashock, Research Plant Pathologist, USDA-ARS

9:35-10:00 Progress towards managing fruit quality in 2020
Peter Oudemans, Professor, P.E. Marucci Center for Blueberry & Cranberry Research & Extension, Rutgers University, Chatsworth, NJ

10:00-10:25 How weeds impact cranberry yield and fruit quality
Thierry Besancon, ‎Weed Science Extension Specialist, Rutgers University, P.E. Marucci Center, Chatsworth, NJ

10:25-10:40 Break

10:40-10:50 VacciniumCAP: Leveraging genetic and genomic resources to enable development of blueberry and cranberry cultivars with improved fruit quality attributes
James Polashock, Research Plant Pathologist, USDA-ARS, P.E. Marucci Center, Chatsworth, NJ; Nicholi Vorsa, Professor, Department of Plant Biology, Rutgers University; Jennifer Johnson-Cicalese, P.E. Marucci Center, Chatsworth, NJ

10:50-11:15 Can we exploit cranberry’s own defenses to fight against phytoplasma infection?
Cesar Rodriguez-Saona, Professor, Department of Entomology, Rutgers University, New Brunswick, NJ; James Polashock, Research Plant Pathologist, USDA-ARS; and Vera Kyryczenko-Roth, P.E. Marucci Center, Chatsworth, NJ

11:15-11:40 Machine learning assists cranberry fruit rot resistance breeding
Joe Kawash, P.E. Marucci Center, Chatsworth, NJ; James Polashock, Research Plant Pathologist, USDA-ARS, P.E. Marucci Center, Chatsworth, NJ; Nicholi Vorsa, Professor, Department of Plant Biology, Rutgers University; Jennifer Johnson-Cicalese, P.E. Marucci Center, Chatsworth, NJ

11:40-12:05 Important farm health and safety concerns related to machinery operation and pesticides application
Bill Bamka, Agriculture & Natural Resources County Agent II, County Extension Dept. Head, RCE of Burlington County, Rutgers New Jersey Agricultural Experiment Station

12:05-1:00 Lunch

1:00-1:20 Cranberry institute – An update
John Wilson, Cranberry Institute, Carver, MA

1:20-1:50 Managing moss in cranberries
Katherine Ghantous, Research Associate, Cranberry IPM, Cranberry Station, East Wareham, MA

1:50 Adjournment- ACGA Board of Directors Meeting

Date: Thursday August 15, 2019
Location: Rutgers University, P.E. Marucci Center for Blueberry & Cranberry Research & Extension, Chatsworth, NJ

AGENDA

CRANBERRY BOGS

8:00–8:30 Refreshments

8:30–8:45 Opening Remarks
Shawn Cutts, President, American Cranberry Growers Association

8:45–9:10 Weed Control in Newly Planted Cranberry Beds (Lower Bogs)
Thierry Besancon and Baylee L. Carr, P.E. Marucci Center, Chatsworth, NJ

9:10–9:25 Cranberry Germplasm Collection: Fuel for Breeding Future Varieties (Bog 1)
Nicholi Vorsa, Jennifer Johnson-Cicalese, and Susan Vancho, P.E. Marucci Center, Chatsworth, NJ

9:25–9:40 Liming to Mitigate pH Lowering Properties of Liquid Fertilizer Applications (Bog 5)
Nicholi Vorsa and Jennifer Johnson-Cicalese, P.E. Marucci Center, Chatsworth, NJ

9:40–10:05 Managing Fruit Quality (Bog 6)
Peter Oudemans, P.E. Marucci Center, Chatsworth, NJ

10:05–10:20 Effects of Reduced Winter Flooding (Bog 9)
Nicholi Vorsa and Jennifer Johnson-Cicalese, P.E. Marucci Center, Chatsworth, NJ

10:20–10:35 2018 Haines Planting: Buggy Sanding to Aid Establishment (Bog 19)
Nicholi Vorsa and Jennifer Johnson-Cicalese, P.E. Marucci Center, Chatsworth, NJ

10:35–11:00 On-going Research on Sucking Insect Pests (Bog 19)
Cesar Rodriguez-Saona, Vera Kyryczenko-Roth, and Robert Holdcraft, P.E. Marucci Center, Chatsworth, NJ

CONFERENCE ROOM

11:20–11:30 Cranberry Statistics
Bruce A Eklund, State Statistician, U.S. Department of Agriculture | National Agricultural Statistics Service

11:30–11:55 Markers for Disease Resistance
James Polashock, Research Plant Pathologist, USDA-ARS

12:00–1:00 LUNCH

Toad bugs, Phylloscelis atra, are an occasional pest of cranberries in New Jersey that can cause economic injury. This insect feeds only on

cranberries and has a single generation per year. It overwinters as eggs. The nymphs appear by the end of June through early September, and the adults from end of July through October (harvest) (see Figure 1). Eggs are laid from end of August through October.

Damage. Feeding damage can be noticed in two stages. First stage feeding damage on vines causes closing in (towards the branch) of the leaves on the new growth. Second stage feeding causes changed in color (reddish to brown) of new growth. The damage can be seen from July until harvest. This damage will cause dying of the branch and the berries to shrivel up. Heavy infestation will result in dwarfed berries.

Management. To determine infestation, lightly sweep problematic beds (bugs should be easy to catch in sweep nets as they are very active). Because this is a new pest there is no threshold established yet. Thus, insecticide applications should be based on the relative number of bugs per sweep compared with other sites and previous history of infestation. Currently, growers can use the following control options: Sevin 4F (broad-spectrum carbamate), Diazinon (broad-spectrum organophosphate), or Actara or Assail 30SG (neonicotinoid insecticides, effective against piercing-sucking insects) (see Figure 2). If infestation is high, treatments should be applied when the nymphs are present (i.e., mid- to late-July; see Figure 1).

For more information, please see “The Cranberry Toad-Bug” by F.A. Sirrine and B.B. Fulton. 1914. New York Agricultural Experiment Station. Bulletin No. 377. Department of Agriculture, Geneva, NY.