Rutgers Cooperative Extension
Seasonal updates on diseases, insects, weeds impacting tree fruit and small fruit (blueberry, cranberry, and wine grape). Fruit Pest Alerts are also available via this category feed.
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Peach:
Oriental Fruit Moth: The timing for third brood control is outlined below. In general, most populations are low and not causing problems.
| OFM 3rd Generation Timing | |||
| Insecticide Type | |||
| County/Region | Degree Days by 7/27 base 45 | Conventional
2100-2200, 2450-2500 |
Diamide
2025-2150, 2375-2450 |
| Gloucester – Southern | 2436 | 1st – past
2nd – 7/27-7/30 |
1st – past
2nd – 7/25-7/27 |
| Hunterdon – Northern | 2217
|
1st – 7/23-26
2nd – 8/4-8/6 |
1st – 7/21-25
2nd – 8/3-8/5 |
Apple:
San Jose Scale (SJS): Some damage is being seen in northern county orchards where nymphs are active. Now is the time to the nymphal stage if you have problem populations. High volume applications are required for control since all twigs and surface areas where nymphs are active need to be covered. Esteem, Centaur, Venerate and Diazinon are choices for control. [Read more…]
Right on time with last year’s observations, adult spotted lanternflies (SLF) were found in Pilesgrove (Salem County) NJ. In 2020 adults at the same location were found on July 23 so despite the earlier hatch observed in May, the phenology is right on track.
Adults were not the dominant life stage, mostly fourth instars were observed. Now is a critical time for management efforts as even these young adults will not become reproductive until September. Adults will congregate on trees, feeding in groups to access the phloem. At this time of year they prefer black walnut and tree of heaven and will gradually move towards red maples, willow, river birch, and sycamore. There are other hosts, these are just the ones we have consistently found high numbers of adults on in NJ.
In 2020, adults dispersed in large numbers to commercial vineyards around September 4. I think this dispersal is a combination of depletion of resources (they are literally sucking the sap out of trees) and density. As NJ populations of SLF increase, they are depleting food resources faster. I expect this movement from wooded areas to vineyards will happen earlier this year, likely mid August. There will be a few bugs here and there, but commercial vineyard managers should wait to apply insecticides until you see the larger influx. Across sites, the 10 adults/vine threshold was reached around the same time last year – although some vineyards had much larger numbers per vine – so this is a good threshold to use for now. I will post management recommendations for the adults soon!
As we approach the end of July, growers need to start monitoring for the cranberry toad bug, Phylloscelis rubra (Figure 1). In a recent study,
Figure 1. Cranberry toad bug.
we showed that even relatively low densities of this insect can cause significant injury to cranberries (Rodriguez-Saona et al. 2020. Characterizing the Feeding Injury Caused by Phylloscelis rubra (Hemiptera: Dictyopharidae) to Cranberries, Journal of Insect Science, 20 (6), 37, https://doi.org/10.1093/jisesa/ieaa143). Thus, monitoring for this insect from the end of July through mid-August is critical.
Life cycle. Cranberry toad bugs feed only on cranberries. This insect 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) (Figure 2). Eggs are laid from end of August through October.
Damage. Feeding damage can be noticed in two stages. 1st-stage feeding damage on vines causes closing in (towards the branch) of the leaves on the new growth. 2nd-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 (Figure 3). Heavy infestation will result in dwarfed
Figure 2. Seasonal changes of the cranberry toad bug.
berries.
Management. To determine infestation, lightly sweep problematic beds (bugs should be easy to catch in sweep nets as they are very active). Currently there is no threshold established for this pest. Thus, insecticide applications should be based on the relative number of bugs per sweep compared with other sites and previous history of infestation. If needed, growers can use the following control options: Sevin 4F (broad-spectrum carbamate), Diazinon, Imidan 70W (broad-spectrum organophosphates), Actara or Assail 30SG (neonicotinoid insecticides, effective against piercing-sucking insects). If infestation is high, treatments should be applied in early August for best control.
Figure 3. Injury caused by the cranberry toad bug.
Image by Jacques Gaimard from Pixabay
by Julie Kikkert, Cornell Cooperative Extension, Cornell Vegetable Program
(Reprinted with permission from Cornell VegEdge Newsletter Vol. 17 (14), July 14, 2021, CCE Cornell Vegetable Program, Canandaigua, NY.)
Scaring birds out of sweet corn and other crops is not new, based on the centuries-old placement of scarecrows dressed in old clothes (oftentimes filled with straw) in fields. However, there are many newer methods from chemical control to loud noises, to laser beams. There are pros and cons to each method and varied costs as well. [Read more…]
Peach:
Oriental Fruit Moth: Some southern county orchards are exceeding the 8 moth per trap threshold this week. This is because trap counts and degree day accumulations indicate the start of the 3rd generation flight. These adults are starting to mate and lay eggs, which will hatch and produce the next brood. Therefor we are near the third brood insecticide timing. Please see table below: [Read more…]
