Eastern Tree Fruit Survey

Hello everyone –

We are putting together a survey to identify key insect problems facing Eastern Tree Fruit growers (specifically for apples and peaches). The goal is to generate a targeted research project to address these needs integrating sociological and economic information with research findings.

Please help by filling out this survey, it should only take a few minutes:

https://ugeorgia.ca1.qualtrics.com/jfe/form/SV_4JFVtXoWDh46jyu

Closeup of bug on peaches in tree

 

 

SLF: 2022 Management Recommendations in Vineyards

by Katarzyna Madalinska and Anne L. Nielsen

Adult SLF are moving into vineyards from the surrounding landscape. The number of SLF on each vine varies greatly within each vineyard and locations in the state. In most vineyards in NJ and PA there is a strong border effect with numbers highest along the outside rows. However, the orientation and shape of your vineyard influences border effects. SLF are actively feeding on grapevines and will continue to feed for 1-2 months. Most SLF are in the upper canopy and as the grapes start to store carbohydrates for the winter, SLF will move down the vine, eventually feeding at the base of the vine. Research suggests that feeding by adult SLF may harm primary bud formation the following season and reduce winter hardiness. There is not a specific treatment threshold, but a good rule of thumb is 10 SLF per vine. Movement into the vineyards will continue for several weeks so multiple insecticide applications may be needed.

Treatment at this time of year is of course complicated by pre-harvest intervals (PHI) for each insecticide and grape variety. It is important to remember that SLF will feed on vines post-harvest. There are several effective insecticides available with pre-harvest intervals and residual activity (Table 1). When treating vines pre-harvest, dead SLF are commonly observed in the clusters. Post-harvest, insecticides such as Danitol or Brigade/Bifenture/bifenthrin have the longest residual activity and are expected to reduce feeding.

There are several reasons to manage adult SLF in September and October during peak movement.

  1. Adults feed on the canes, cordon, and trunk of grape vines. Excessive feeding has been shown to lower winter hardiness by >1.5°C.
  2. SLF females lay egg masses in October. Killing females prior to egg laying will decrease population growth the following year.

Table 1. Effectiveness of Insecticides Against Spotted Lanternfly Adults. Modified recommendations from Leach et al. Crop Protection 2019 v. 24  DOI:10.1016/j.cropro.2019.05.027

Trade name Active ingredient SLF Activity Rate per acre Seasonal Allowance Residual Activity PHI

(days)

REI

(hrs)

Labeled for SLF?
Mustang Maxx 0.8EC cypermethrin Good 4 oz 24 oz <3 1 12 Yes, 2(ee)
Scorpion 35SL dinotefuran Excellent 5 oz. 20.9 oz <7 1 12 Yes, 2(ee)
Actara 25WDG thiamethoxam Excellent 3.5 oz 7.0 oz <14 5 12 Yes, 2(ee)
Carbaryl 4L carbaryl Excellent 1-2 qt 10 qt 7 7 12 No
Avaunt 30DG indoxicarb Fair 6 oz 12 oz 7 7 12 Yes, 2(ee)
Danitol 2.4EC fenpropathrin Excellent 16-21.33 oz 42.66 oz >26 21 24 Yes, 2(ee)
Brigade 2EC bifenthrin Excellent 3.2-6.4 oz. 6.4 oz 21 30 12 Yes, 2(ee)

 

There are several reasons to manage adult SLF in September and October during peak movement.

  1. Adults feed on the canes, cordon, and trunk of grape vines. Excessive feeding has been shown to lower winter hardiness by >1.5°C.
  2. SLF females lay egg masses in October. Killing females prior to egg laying will decrease population growth the following year.

Management Recommendations SLF nymphs in 2022

By Katarzyna Madalinska and Anne Nielsen

New Jersey is currently in its 5th year of invasion from spotted lanternfly. Populations are now widespread throughout the state and have established in almost every county in NJ. SLF pressure is variable throughout NJ’s counties, and we do not currently have a threshold for management of nymphs.

1st instar SLF in NJ vineyard – photo by K. Madalinska

SLF nymphs are hatching throughout the state and will continue to do so in the coming weeks. Despite seeing nymphs within the vineyard, we do not recommend immediate treatment at this time. Hatch will occur over a multiple week period depending on the site of egg masses and exposure. The early instars feed on new growth, particularly the underside of leaves and shoots. At this point there is no evidence that early instar feeding results in plant injury or yield loss. Peak abundance of SLF nymphs in vineyards is during their 1st to 2nd instars approximately and 2-3 weeks after the first hatch. Management during their 2nd instar will target the highest number of individuals and prevent additional treatments against nymphs. This timing typically coincides with other key pests within the vineyard, such as grape berry moth and Japanese beetle. Many broad-spectrum insecticide options for grape berry moth or Japanese beetle will also effectively kill SLF nymphs (see table) and insecticides against SLF will not be needed until the adult stage.

Trade name Active ingredient Class Rate per acre Seasonal Allowance SLF* GBM JB
Brigade 2EC bifenthrin Pyrethroid 3.2-6.4 oz 6.4 oz E* E
Actara thiamethoxam Neonicotinoid 3.5 oz 7.0 oz E* G
Assail 30SG acetamiprid Neonicotinoid 2.5-5.3 oz 2 times G G F
Carbaryl 4L carbaryl Carbamate 1-2 qt 10 qt E G G
Avaunt indoxicarb Oxadiazine 6 oz 12 oz. E* G G
Danitol 2.4EC fenpropathrin Pyrethroid 16-21.33 oz 42.66 oz E* E E
Belay clothianidin Neonicotinoid 2.0–6.0 oz. 12 oz. G G G
BaythroidXL cyfluthrin Pyrethroid 1.6-3.2 oz 12.8 oz E E

Always consult the label for further instructions.

*2(ee) approved for SLF in NJ grapes

E = excellent control
G = good control
F = fair control

SLF Adults Are Here (again)

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!

Spotted Lanternfly Hatch

Spotted lanternfly nymphs

photo by Autumn Angeles

Spotted lanternfly nymphs are hatching throughout the state and first instars are present in multiple vineyards. Lanternfly overwinters in the egg stage and hatch is quite protracted, likely depending on the microhabitat where eggs are laid. In our surveys in 2019-2020, we identified a 2 year delay from the time SLF adults are first identified in the woods bordering vineyards and movement of the adults into the vineyard and laying eggs at levels that require management.

While it may seem counterintuitive, management is not needed as soon as SLF hatches. There is currently no evidence that the nymphs cause any yield loss or plant injury. However, this is an invasive species that requires management and there is no threshold for management against the nymph stage.

Best management practices against SLF nymphs in vineyards are to time management with other key insect management such as grape berry moth or Japanese beetle. This will not only save on insecticide costs but will also allow for all of the nymphs to hatch from the egg masses. See the table below on efficacy of materials targeting multiple vineyard pests.

Trade name Active ingredient Class Rate per acre Days of activity SLF GBM JB
Brigade 10WSB bifenthrin Pyrethroid 16 oz. 14 E E
Actara 25WDG thiamethoxam Neonicotinoid 3.5 oz 7 E G
Assail 30SG acetamiprid Neonicotinoid 5.3 oz <7 G G F
Carbaryl 4L carbaryl Carbamate 2 qt 7 E G G
Avaunt 30DG indoxicarb Oxadiazine 6 oz 7 E G G
Danitol 2.4EC fenpropathrin Pyrethroid 21.33 fl oz 7 E E E
Belay clothianidin Neonicotinoid 6 oz. G G G
Baythroid cyfluthrin Pyrethroid 3.2 oz 7 E E

E = excellent control
G = good control
F = fair control

SLF: Current Management Recommendations in Vineyards

By Katarzyna Madalinska, Megan Muehlbauer, George Hamilton, and Anne L. Nielsen

Spotted lantern flies on a tree

Spotted lanternfly adults congregating on tree of heaven

Spotted lanternfly was first found in northern NJ in 2018. Since then, populations are rapidly increasing and will substantially surpass those seen in 2019. Management of this pest is critical as we are still in the exponential growth phase of the population. There has been a 1300% increase in nymphs reported this year, which will most likely reflect higher numbers of adult SLF from previous years. This means that pressure from SLF adults will be felt more intensely by more vineyards this year.

The predominant life stage of the spotted lanternfly (SLF) seen across New Jersey during this time of year is the adult stage. That does not mean you will not see juveniles as well, which can appear black with white spots or their last juvenile stage which are red with black and white spots. The adult stage will be present until first frost.

Our current understanding of SLF adult behavior may aid in targeting management in vineyards. Right now, adult SLF are congregating in large numbers on hardwood trees along hedgerows or in bordering woods. It can be useful to identify one or a few spots around your vineyard where large numbers of SLF are feeding. One option for action at this time could be to target these trees with a backpack sprayer

using an insecticide labeled for SLF control as well as labeled for the tree species being treated. This is expected to decrease populations in general before they start reproducing but MAY not result in a decrease of pressure within the vineyard. While adults may be observed in the vineyard, right now SLF movement into the vineyard is minimal and is expected to dramatically increase in September and October. During the period of predicted peak SLF feeding within vineyards (September and October), the vines are storing carbohydrates for winter and excessive feeding by SLF can decrease winter hardiness by 1.5oC.

Movement into the vineyard will occur across several weeks and a strong edge effect will occur. However, SLF do not discriminate between vines that have been harvested or not. The treatment threshold used in South Korea is 10 SLF per vine, however, a more conservative threshold may be warranted to reduce populations and injury to the vines. If you can identify the more vulnerable parts of your vineyard you can target your insecticide application in those areas. The key is the application of an insecticide with long residual activity. There are several effective options for insecticide application (see Table 1).

Insecticides and their application rates are broken down in the table below. Be mindful of allowable uses and PHI when choosing an insecticide. After harvest there is more flexibility in insecticides available for application. We recommend the use of insecticides with a longer residual activity such as Bridgade post-harvest.

Table 1. Effectiveness of Insecticides Against Spotted Lanternfly Adults. SLF activity derived from PSU extension and Leach et al. Crop Protection 2019 v. 24 DOI:10.1016/j.cropro.2019.05.027

Trade name Rate per acre Total Use Systemic, Contact, Ingestion PHI (days) REI (hrs) Days of activity Labeled for SLF? SLF activity
Malathion 8F 1.88 pt 1.88 pt C, I 3 36 3-7 Yes, 2(ee) Excellent
Baythroid XL 2.4-3.2 oz 12.8 C, I 3 12 No Good
Scorpion 35SL 5 fl oz (foliar) 20.9 oz S, C, I 1 12 <14 Yes, 2(ee) Exc.
Brigade 10WSB 8-16 oz. 16 oz C, I 30 12 21 Yes, 2(ee) Exc.
Mustang Maxx 0.8EC 4 fl. oz. 24 oz C, I 1 12 <7 Yes, 2(ee) Good
Actara 25WDG 3.5 oz 7 oz. S, C, I 5 12 <21 Yes, 2(ee) Exc.
Assail 30SG 5.2 oz 2/yr S, C, I 3 48 0 Yes, 2(ee) on nymphs only Good
Carbaryl 4L 2 qt 10 qt C, I 7 12 <14 No Exc.
Avaunt 30DG 6 oz 2/yr C, I 7 12 0 Yes, 2(ee) Fair
Admire Pro 1.4 fl oz 2.8 oz C, I 0 12 <7 No Good
Belay 4-6 oz (foliar) 1/yr S, C, I 0/30 12 No Good/Excellent
Prepared by PennState  with modifications by Anne Nielsen

 

There are several reasons to manage adult SLF in September and October during peak movement.

  1. Adults feed on the canes, cordon, and trunk of grape vines. Excessive feeding has been shown to lower winter hardiness by >1.5°C.
  2. SLF females lay egg masses in October. Killing females prior to egg laying will decrease population growth the following year.

In October, female SLF prefer to lay egg masses on a relatively smooth surface that is positioned horizontally.  Within a vineyard, egg masses may be laid on posts, farm equipment, and the grape vines themselves. When looking for egg masses on your vines, be sure to examine any layers of peeling bark on the trunk or canes. However, if many egg masses are present in your vineyard, there are substantially more in any bordering wooded areas. Currently, we feel that management against the nymphs in the spring is more effective than targeting egg masses with an insecticide.