Asian Longhorned Beetle Regulated Area - Updated

The regulated area for the Asian longhorned beetle infestation has been expanded. The updated area includes all of the city of Worcester, and parts of the towns of Boylston, Holden, Shrewsbury, and West Boylston. Download the latest map here, or visit the official Massachusetts ALB Eradication Program page for more information.

Chrysanthemum White Rust detected in Massachusetts

Chrysanthemum white rust (Puccinia horiana, "CWR"), a serious fungal disease of chrysanthemums, has been discovered in Massachusetts. Infected plants were found at nurseries and at retail locations, with diagnoses confirmed by plant pathologists from USDA APHIS-PPQ. This pathogen can spread quickly in greenhouse and nursery environments, causing severe crop losses.

Over the last 25 years, localized introductions of chrysanthemum white rust have occurred within the United States or Canada and have subsequently been eradicated. Earlier this month, CWR was reported to have overwintered in an outdoor planting of mums at a residential property in Connecticut, and was also found at nurseries in Pennsylvania and Michigan. CWR is a pest of quarantine significance in the United States, requiring state and federal regulatory action. The Massachusetts Department of Agricultural Resources and USDA APHIS-PPQ are currently working together with nurseries to eradicate it from Massachusetts.

Chrysanthemum white rust attacks several species of chrysanthemums, including potted mums, spray mums, and garden mums. The symptoms of this disease are very distinct. Light green to yellow spots up to 5mm in diameter appear on the upper surface of the leaf. The spots become brown and necrotic with age. Raised beige to pink pustules form on the underside of leaves. These pustules become white with age. Pustules are most common on young leaves and flower bracts but may form on any green tissue or the petals. Symptoms are more likely to be observed during or following cool, wet weather.

For more information about chrysanthemum white rust, including lists of susceptible and resistant species and a detailed eradication protocol, see our fact sheet. If you think you have seen Chrysanthemum White Rust, please call the MDAR Plant Pest Hotline at 617-626-1779, or report it on our website.

To sign up for pest and pathogen alerts from the Massachusetts Introduced Pests Outreach Project, visit this page.

Ruling out the Asian Longhorned Beetle

The Asian longhorned beetle attacks several different types of trees. For those of you who are concerned about this pest and who are just starting to examine your local trees, it can be overwhelming to think that every hole, pit and pile of sawdust you find could be ALB. Here are some tips that will help you rule out ALB as the cause of tree damage:

• ALB attacks only hardwood trees (maple, birch, willow, etc.). Pines, fir, cedar, juniper and other conifers are "softwood" trees and are not susceptible to ALB. Other trees that are not susceptible to ALB: alder, dogwood, hickory, walnut.
• ALB is not considered a pest of oak trees. Records indicate an oak tree in New York was found with ALB damage, but the tree was located next to many heavily infested trees that were known hosts for ALB.
• There are many beetles and other insects that damage trees by boring holes in the wood or damaging the bark. It takes an experienced eye to detect the difference between damage caused by ALB and other insects. To learn more, view our ALB fact sheet, visit our Worcester photo gallery, or download this excellent training guide from the Canadian Forest Service.
  

Every infestation of ALB allows researchers to learn more about the preferences of this pest. The list of potential host species is regularly updated by the USDA, and the latest version can be downloaded here.