Veg IPM Update: Allium leaf miner 04/30/18

Allium Leaf Miner

Allium leaf miner (ALM) adults (flies) were trapped on sticky cards, and moderate levels of feeding signs were discovered late last week at sites in Lawrenceville and Pennington (Mercer County).  Additionally, volunteer garlic in the Chesterfield area of Burlington County was infested.  As yet, no adult activity or feeding has been found at the more northern sites in Milford, Pittstown and Asbury (Hunterdon County).  Affected crops include chives, scallions, garlic and leeks.  Although we are 2-3 weeks behind last spring’s development, the ALM flight now seems to be well underway in parts of the state.  With warm weather forecast for the remainder of this week, growers in the northernmost counties should expect infestations to occur there as well.

Floating row covers, kept on until the first flight ends will help minimize access to plants.  Insecticide applications targeting adults may be helpful as well, although frequency of applications is uncertain.  Spinosyn materials (Radiant, Entrust (OMRI approved)), pyrethroids (Mustang Maxx, Warrior), and pyrethrin materials (Pyganic (OMRI approved)), neonicotinoids (Scorpion, Venom) and the insect growth regulator Trigard are labeled for miner control.

Adult activity and observations of feeding will be reported on in the IPM Update as they occur.  At this time, all growers should respond to the onset of the first adult generation.  We will attempt to identify the end of the first flight so that growers know when the risk of infestation has abated.

 

 

 

Veg IPM Update: Allium leaf miner 04/12/18

Allium Leaf Miner

Allium leaf miner (ALM) adults (flies) and a very limited number of leaves with feeding signs were discovered Thursday at sites in Lawrenceville and Pennington (Mercer County).  As yet, no adult activity or feeding has been found at the more northern sites in Milford, Pittstown and Asbury (Hunterdon County).  Affected crops include chives, scallions, garlic and leeks.  Indications are that we are 2-3 weeks behind last year’s development, but warmer weather through the coming weekend will surely result in more apparent infestations.

Floating row covers, kept on until the first flight ends will help minimize access to plants.  Insecticide applications targeting adults may be helpful as well, although frequency of applications is uncertain.  Spinosyn materials (Radiant, Entrust (OMRI approved)), pyrethroids (Mustang Maxx, Warrior), and pyrethrin materials (Pyganic (OMRI approved)), neonicotinoids (Scorpion, Venom) and the insect growth regulator Trigard are labeled for miner control.

Adult activity and observations of feeding will be reported on in the IPM Update as they occur.  At this time, all growers should respond to the onset of the first adult generation.  We will attempt to identify the end of the first flight so that growers know when the risk of infestation has abated.

 

 

 

Veg IPM Update: Allium leaf miner 04/06/18

Allium Leaf Miner

     

 

Allium leaf miner (ALM) traps (sticky cards) were deployed on March 20, in overwintered allium crops at sites in Lawrenceville and Pennington (Mercer County), and Milford, Pittstown and Asbury (Hunterdon County).  These traps have been checked weekly since that time and have returned no positive ALM catches.  Host crops at these sites (chive, scallion and garlic)  were free of injury as of April 5.  In 2017, traps placed at these locations were already catching ALM adults by the end of March, and feeding injury was easily discovered on chives.  Indications are that we are 2-3 weeks behind last year’s development.

We do have confirmed injury and sighting of adult ALM on scallions in high tunnel production in the Pennington area, but insect development in this warmer protected environment is not indicative of what is occurring outdoors.  As weather warms, expect adults to emerge and become active.  They will feed on available allium crops, which will include overwintered chives and garlic as well as newly transplanted onions and scallions and leeks.  Look for characteristic dots (see photo at center) on the upper portion of upright leaves.  Expect that any plant with these feeding/egg laying scars is infested.  Larvae will tunnel downward (see photo at right); ultimately pupating in the neck of the plant (see late instar larva at left).

Floating row covers, kept on until the first flight ends will help minimize access to plants.  Insecticide applications targeting adults may be helpful as well, although frequency of applications is uncertain.  Spinosyn materials (Radiant, Entrust (OMRI approved)), pyrethroids (Mustang Maxx, Warrior), and pyrethrin materials (Pyganic (OMRI approved)), neonicotinoids (Scorpion, Venom) and the insect growth regulator Trigard are labeled for miner control.

Adult activity and observations of feeding will be reported on in the IPM Update as they occur.  We will attempt to identify the beginning and end of the first flight so that growers know when they should initiate control tactics and when the risk of infestation has abated.

 

 

 

Veg IPM Update: Allium leaf miner 10/25/17

Allium Leaf Miner

     

 

A sample of unsprayed/unprotected volunteer garlic near Asbury on the Hunterdon/Warren County border today showed 68% of plants infested with allium leaf miner (ALM).  These maggots were all later stage, and found in the necks, about 1″ above the bulb (see photo at upper left).  We should expect that all untreated/unprotected allium crops are similarly affected at this time.  Interestingly, 100% of infested plants had visible feeding/egg laying scars (see photo at center above), while 100% of uninfested plants showed no visible signs.  None of the plants had mines visible on the surface, but cross sections of the neck revealed clean tunnels the maggots had created on their way down (see photo at right, above).

Our colleagues at Cornell, operating in the Hudson Valley had notified us that they had had no success catching ALM adults on sticky cards, and we have had the same difficulty in NJ this Fall.  This is unlike our experience in the Spring, when we were able to catch numerous individuals at nearly every trap site.  Additionally, the generation of adults emerging in the Spring here in NJ heavily infested chives; the earliest possible host.  This Fall, chives appear to be largely uninfested, while onions, scallions, and leeks are showing the most feeding/egg laying scars.

Be aware that if no program of protection was enacted roughly 3 weeks ago, Fall allium crops may be heavily infested at this time.

 

Veg IPM Update: Week Ending 10/04/17

Note:  Today’s edition is the last regular IPM Update of the season.  We will continue to monitor late season crop pests and will publish updates as necessary.

Sweet Corn
Corn earworm (CEW) moth catches declined dramatically over this past week with evening temperatures dropping into the high 40s in many locations (see CEW blacklight map at left).   In this map, areas in green roughly correspond to a 3-day schedule, while blue areas are in the 4-5 day range.  Blue points within larger green areas should be considered “outliers”, and the broader color scheme in any particular region is more representative of the population. The current situation may change with somewhat warmer night temperatures forecast toward the end of the week.  Should night temperatures begin to approach 60F or more, growers should consider treating remaining silks on a 3-4 rather than a 4-5 day schedule.   Be aware that synthetic pyrethroids have become less effective at managing ear infestations from this pest over the past several years.  For this reason, it is advisable to include products in the IRAC group 28 (Coragen, Besiege) or IRAC group 5 (Radiant, Entrust (OMRI approved)).

The highest nightly CEW blacklight trap catches are as follows:

Georgetown   5 Farmingdale   2 Chester   1
New Egypt   5 Allamuchy   1 Centerton   1
Crosswicks   3 Beckett   1 Eldora   1
Matawan   3 Belvidere   1 Eldora   1

[Read more…]

Veg IPM Update: Week Ending 9/27/17

Sweet Corn
European corn borer (ECB) catches have again fallen to levels too low to register a map image.  This pest is not much of a threat at this point, with most remaining plantings in silk.  ECB feeding in less mature NJ sweet corn plantings is nearly non-existent now.  Sprays for fall armyworm and corn earworm will manage any ECB larvae at this time.  [Read more…]