Archives for April 2021

If you are unfamiliar with this pest

• Dr. Kunkel presenting “Seeing red? Redheaded flea beetle”  Seeing red? Redheaded flea beetle (scroll to the bottom of the webpage)
• NC State: Red-headed flea beetle biology and management
• Nursery Mag: Don’t get foiled by the flea beetle
• If you do not know how to calculate Growing Degree-days (GDD₅₀): Obtaining your local growing degree-day information

*****Please take this 5-minute survey pertaining to your concerns with Redheaded flea beetles in NJ (click here)***** 

If you are interested in donating infested plant material or conducting on-farm RHFB research. Please contact twaller@njaes.rutger.edu (856-451-2800 ext.1)

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Redheaded Flea Beetle (RHFB) Considerations

Ideally when controlling high-density populations of RHFB, fall applications of long-lasting systemic materials can provide a strong knock-down of larvae populations destined to emerge in the following spring. Establishing a reserve of systemic materials in the soil and root zone late-season or early this season will greatly increase control efforts made later and can reduce the number of overall applications made specifically for RHFB.  A two-pronged approach of systemic and contact insecticides can manage active adults and larvae throughout the season.  For current season control: systemic insecticide drench or ‘sprench’ (*consider backpack units) near planting / potting-up, or a month prior to adult emergence (now for southern NJ), will provide the reserve of systemic activity required to reduce larvae and adult populations later. Contact material applications should also be considered for adult and larval treatments but must be made at sufficient volumes to guarantee ‘contact’. Contact-only driven spray regimes can provide good results, however the need to protect new growth will be ever present. When choosing materials, also consider the other pests targeted by that compound to maximize the value of your investment. Targeting the larval stage will reduce the number of adults present to lay the next generation of eggs.

Timeline for New Jersey growers and landscape professionals 

• NOTE: Calendar date predictions based on USPEST.ORG using weather-stations for Upper Deerfield (NJ50), Howell/Freehold (NJ10), and High Point (NJ59). These are predictions and scouting should commence at least 2 weeks prior to listed dates

Please download this RHFB quick-look guide of the information provided below (click here)

Projected GDD50 accumulation as of 4/26/2021
Region	Location	26-Apr	1-May	1-Jun	1-Jul	Aug. 1st
Southern	Upper Deerfield (NJ50)	163	231	638	1315	2158
Central	Howell / Freehold (NJ10)	110	166	514	1135	1929
Northern	High Point (NJ59)	61	99	313	765	1327
Forecast: NOAA NCEP Coupled Forecast System model version 2 (CFSv2) forecast system (3.5 months) (USPEST.ORG)

 

Redheaded flea beetle – life stage predictions for South, Central, and Northern New Jersey with material considerations
		TARGET RANGE	TARGET RANGE	Upper Deerfield (NJ50)		Howell (NJ10)		High Point (NJ59)
Growth Stage	Gen.	GDD50 LOW	GDD50 HIGH	LOW (DATE)	HIGH (DATE)	LOW (DATE)	HIGH (DATE)	LOW (DATE)	HIGH (DATE)
Egg hatch – larvae	1st	242	600	2-May	29-May	10-May	6-Jun	24-May	21-Jun
Adults                            (feeding / laying eggs)	1st	517	1028	24-May	20-Jun	1-Jun	27-Jun	16-Jun	14-Jul
POTENTIAL OVERLAP OF GENERATIONS / STAGES
Egg hatch – larvae	2nd	1570	1860	10-Jul	21-Jul	17-Jul	29-Jul	11-Aug	27-Aug
Adults                            (feeding / laying eggs)	2nd	1878	2318	22-Jul	7-Aug	30-Jul	16-Aug	28-Aug	1-Oct

Note: Updated 4/26/2021 – Estimated using USPEST.org, 3.5-month CFSv2 based seasonal climate forecast, simple average growing degree-days, min temp: 50F, max temp: 95F. Growing degree-day ranges based on Dr. Kunkel’s work out of the University of Delaware. 

• 1^st generation larvae: 242-600 GDD₅₀ 
  • Observation of larval activity on the outside of root balls occurs during this timeframe, meaning they may be active earlier
  • Systemic treatments should be initiated late fall or immediately on susceptible hosts (southern NJ)to guard plants from adult feeding later this season.
    • Materials containing neonicotinoids [4A] and cyantraniliprole [28] (Mainspring) are considered particularly fast and effective, however lack the staying power of similar chemistries such as Chlorantraniliprole [28] (Acelepryn) that takes longer to translocate from soil reserves.
    • Organophosphates (1B) Acephate (Orthene, Acephate 97UP) are also a systemic options.
  • During larval development contact materials containing bifenthrin, azadirachtin, tolfenpyrad, cyclaniliprole + flonicamid, entomopathogenic fungi (Beauveria bassiana) or beneficial nematodes should be seriously considered when attempting to knock-down forthcoming adult populations.

• 1^st generation adults: 517-1028 GDD₅₀ 
  • Feeding damages will be apparent on susceptible hosts, scout to determine best time of day for applications, materials such as Captiva Prime or another agitator may be useful in driving the beetles out of hiding (which they do EXTREMELY well).
  • Continuation of systemic materials, use contact materials to directly target the adults.
  • Keep weed populations to a minimum, adults may feed on nearby weed species such as dog fennel, pigweed, and knotweed, thus avoiding pest control efforts on susceptible crops

• 2^nd gen. larvae: 1570-1860 GDD₅₀
  • Potential for considerable overlap of larval-adult developmental stages
  • Continuation of systemic materials, use contact materials to directly target the larvae and adults.

• 2^nd gen. adults: 1878-2318 GDD₅₀
  • Continuation of systemic materials, use contact materials to directly target the larvae and adults.
  • Keep weed populations to a minimum

• A third generation is suspected to be possible in the southern and central regions of New Jersey

IT IS CRITICAL TO ROTATE AS MUCH AS POSSIBLE BETWEEN IRAC GROUPS DUE TO THE NUMBER OF POTENTIAL APPLICATIONS

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.

Boxwood Blight risk model update (4/26 – 5/1) 

Boxwood Blight Risk Assessment as of 4/26/2021
Region	Location	CODE	26-Apr	27-Apr	28-Apr	29-Apr	30-Apr	1-May
Southern	Upper Deerfield	NJ50	Very Low	Very Low	Very Low	Very Low	Very Low	Very Low
Central	Howell / Freehold	NJ10	Very Low	Very Low	Very Low	Very Low	Low	Very Low
Northern	High Point	NJ59	Very Low	Very Low	Very Low	Low	Low	Very Low
Please check your local boxwood blight risk here (click here)

 

*****Please take this 5-minute survey pertaining to your concerns with Redheaded flea beetles in NJ (click here)***** 

Please contact Tim Waller – Cumberland Co. – RCE for more information – twaller@njaes.rutgers.edu – 856-451-2800 ext. 1