Landscape Pest Notes for April 2023

Cool, Moist Springs, Aphids, and Lady Beetles: A cool, moist spring will be good for lady beetles, and other predators feeding on aphids. A single lady beetle larva will eat between 200-300 aphids before becoming an adult. As adults, females eat up to 500 aphids before laying eggs! Before applying any treatment sprays against aphids, monitor for predators and consider if the infested plants are in a key location. If not, then let natural predators provide control.

Bugs on plant

Species of lady bird beetle larva that specializes feeding on aphids. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

 

Management of Aphids Using Soaps?: Although the use of insecticidal soap is stated to be a “biorational” pesticide and is recommended within IPM programs,  research has indicated that they typically provide less than satisfactory controls against aphids within the landscape. Insecticidal soap is commercially available under the trade name M-PEDE and although aphids are included on the label, the research indicates only a 5% to 10% reduction of an aphid population with a single application when applied at label rates. The M-PEDE label indicates the less than satisfactory controls it achieves against aphids with a single application. Conversely, it is important to emphasize that insecticidal soap will provide outstanding efficacy against adelgids (i.e., spruce galls & hemlock woolly adelgids) and is highly recommended as a control material against these insects (Precautionary note: As similar to oils, some soap sprays may remove the blue coloration on conifers).

Watering plant

Both horticultural oil & insecticidal soap sprays require good coverage to provide effective controls. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

This blog includes some of the common insect/mite pests often encountered in NJ landscapes during the month of April. They may require monitoring & intervention to prevent plant damage. Also some abiotic concerns & scouting tips are included. The insect/mite pests reviewed are native holly leaf miner, spongy moth, honey locust spider mite, honey locust plant bug, eastern tent caterpillar, southern red spider mite, hemlock woolly adelgid, & hemlock rust mite.

[Read more…]

NJ Department of Environmental Protection Issues Burn Permit for Frost Protection – Through April 14

(TRENTON) – With the state expected to experience colder spring temperatures, the Department of Environmental Protection has agreed with NJ Dept of Agriculture Secretary Douglas Fisher’s request to allow farmers to do controlled open burning or use specialized torches known as smudge pots to protect crops from damage beginning Friday, April 7, through Friday, April 14.

These cold events could adversely affect some of the fruit, vegetable, and floriculture crops.

Note: The NJDEP and New Jersey Forest Fire Service caution all farmers and agriculture businesses with respect to the use of open burning in high wind velocity conditions. Please take note that farmers are encouraged to utilize smudge pots is warming as necessary during higher wind conditions. Use of open burning when wind velocity is greater than 5mph is strictly prohibited, may contribute to wildfire risk, and can carry significant penalties. [Read more…]

NJ Department of Agriculture Issues Burn Permit for Frost Protection – Through April 14

(TRENTON) – With the state expected to experience colder spring temperatures, the Department of Environmental Protection has agreed with NJDA Secretary Douglas Fisher’s request to allow farmers to do controlled open burning or use specialized torches known as smudge pots to protect crops from damage beginning today, Friday, April 7, through Friday, April 14.

These cold events could adversely affect some of the fruit, vegetable, and floriculture crops.

Note: The NJDEP and New Jersey Forest Fire Service caution all farmers and agriculture businesses with respect to the use of open burning in high wind velocity conditions. Please take note that farmers are encouraged to utilize smudge pots is warming as necessary during higher wind conditions. Use of open burning when wind velocity is greater than 5mph is strictly prohibited, may contribute to wildfire risk, and can carry significant penalties. [Read more…]

HIGH potential for Boxwood Blight this Thursday 4/6

There is a potential for boxwood blight infections this WEDNESDAY and THURSDAY throughout much of NJ – especially central regions. Thursday’s high temperatures coupled with prolonged periods of leaf wetness overnight will contribute to the spread of boxwood blight infections.

If BWB is important to your business Use the USPEST – PUSH Alerts – (click here) – to setup weekly email alerts. Create an account, watch the tutorial, and then set up your subscriptions. You select which locations (as many as you like), days you want to receive emails (pick Sunday/Monday), and what you would like to receive alerts about (BWB and a variety of other pests and diseases). Rutgers is not directly affiliated, however this is an incredible tool. 

  • It is time to begin protective fungicide applications in high value areas if you have not already done so! 

  • Protective fungicide applications should remain in effect or be initiated immediately for Boxwood Blight in “Infection risk or High Risk areas”. 
  • If your area is not listed (throughout all of NJ please visit the USPEST.ORG Boxwood Blight Risk Model – CLICK HERE TO CHECK YOUR LOCAL PREDICTIONS

Boxwood Blight risk-model information, considerations, and links:

Boxwood Blight Risk Assessment as of 4/4/2022
Region Location CODE 3-Apr 4-Apr 5-Apr 6-Apr 7-Apr 8-Apr
Southern Upper Deerfield NJ50 Very Low  Low  Minor Risk Very Low  Very Low  Very Low 
Central Howell / Freehold NJ10 Very Low  Low  Minor Risk Very High Very Low  Very Low 
Northern High Point NJ59 Very Low  Very Low  Low  High Risk Very Low  Very Low 
Monday Tuesday Wednesday Thursday Friday Saturday
 Please check YOUR LOCAL risk (click here)

[Read more…]

Some Early Spring Insect Pests of Christmas Trees

The accumulation of heat units (Growing Degree Days (GDD) will soon begin to increase rapidly in New Jersey as we approach the early weeks of April. If past histories or present-day monitoring indicate the need for interventions, then the best control windows for numerous insect/mite pests are beginning to occur. The following is an incomplete listing of a handful of some of our early-season Christmas tree insect pests that may need to be scouted & possibly controlled. Those included in this blog are the European pine sawfly, Eastern spruce gall adelgid, Cooley spruce gall adelgid, Nantucket pine tip moth, Pales weevil, White pine aphid, & Pine bark adelgid.

Christmas trees in field

After many years, these slow growing Colorado blue spruce trees are close to reaching their peak selling growth stage as Christmas trees. (Photo Credit: Steven K. Rettke, Rutgers Coop. Ext.)

 

[Read more…]

Immediate potential for Boxwood Blight 3/24 and 3/25 – First infection potentials

There is a potential for new boxwood blight infections this FRIDAY and SATURDAY throughout much of NJ – especially central regions. Increased temperatures and prolonged periods of leaf wetness will contribute to the spread of boxwood blight infections.

  • It is time to begin protective fungicide applications in high value areas if you have not already done so! 

  • Protective fungicide applications should remain in effect or be initiated immediately for Boxwood Blight in “Infection risk or High Risk areas”. 
  • If your area is not listed (throughout all of NJ please visit the USPEST.ORG Boxwood Blight Risk Model – CLICK HERE TO CHECK YOUR LOCAL PREDICTIONS

Boxwood Blight risk-model information, considerations, and links:

Boxwood Blight Risk Assessment as of 3/22/2023
Region Location CODE 22-Mar 23-Mar 24-Mar 25-Mar 26-Mar 27-Mar NOTES
Southern Upper Deerfield NJ50 Very Low  Low Low  Infection Risk Very Low  Very Low 
Central Howell / Freehold NJ10 Very Low  Low HIGH Risk HIGH Risk Very Low  Very Low  High prob. of first BWB infections
Northern High Point NJ59 Very Low  Very Low   Infection Risk Very Low Very Low  Very Low 
 Please check YOUR LOCAL risk (click here)

(input your area code – select closest weather station – check 7-14 prediction – click on graph / table)

These advisories are general in nature, change rapidly over time, are site-specific…therefore  Someone from your business should be using this risk model daily if boxwood is important to your financial stability– In 30 seconds you can have a better idea of boxwood blight (and other pathogen) activity in your immediate area! Please contact Tim Waller if you need help using this service (twaller@njaes.rutgers.edu), we want to help! 

Fungicides; 

  1. You very well may have these materials already applied as ‘cover-sprays’ – But – be mindful that protectant fungicides loose efficacy the more rain (or overhead irrigation) they are subjected to, and reapplication may be warranted.
  2. ROTATE between Fungicide Resistance Action Committee (FRAC codes) to avoid this pathogen becoming resistant to specific chemicals

Format: [FRAC code]: Chemical name (Trade names * no endorsement implied, other options exist)  

  • [M05]: Chlorothalonil (Daconil WS)
  • [M05 + 1] Chlorothalonil + Thiophanate methyl (Spectro 90WDG)
  • [11] Trifloxystrobin + [7] Fluopyram  (Broadform)
  • [11] Trifloxystrobin + [3] Triadimefon (Armada 50WDG)
  • [M03] Mancozeb
  • [12] Fludioxonil (Medallion WDG)
  • [3] Tebuconazole (Torque)BW

DISCLAIMER: The label is the law, always refer to it for allowable host crops, use-restrictions, application rates, reapplication intervals, re-entry intervals (REI), and mix compatibility information. Production and pesticide information on this site are for private/commercial pesticide applicators and landscape professionals only, and are NOT for home gardener use. Provided materials represent examples and do not cover all possible control scenarios. Trade-names listed do not imply endorsement and are used as examples only. Please contact your local agent or chemical sales representative for more information or to discuss additional pest management options.

Resources 

Background on the pathogen: