As of Friday, April 21, we confirmed that ALM is in south Jersey and it is likely that it can be found throughout the state. Infested field chives were found in East Vineland as well as in backyard chives in Atlantic County and onion sets in the Middlesex/Monmouth County area. Feeding scars have been found in wild garlic which is abundant in New Jersey. So far, adult flies have only been trapped in chives. Given how chives are harvested, it is difficult to assess how damaging the fly will be to the chive crop. More of a problem will be protecting longer term crops like leeks and onions.
It is unlikely that ALM spread over the entire state in the past year since its discovery in Pennsylvania last spring. Probably ALM has been in the state for a while but either the population wasn’t that large and/or the damage wasn’t recognized. We have a lot to learn about this pest and we will be communicating with Penn State and other researchers about its biology, impact and control measures.
