Invasive species have had significant negative economic and ecologic impacts upon various ecosystems in Maryland for more than 100 years. The accidental introduction of the fungus that causes chestnut blight affected forest ecosystems across the State. More recently, the gypsy moth has cost millions of dollars in control and management.

Increased international trade and travel has led to a significant increase in the accidental movement of species into new areas. Additionally, fragmentation and disturbance have made forest ecosystems more vulnerable to establishment and proliferation of invasive species. More than 400 non-native insects that feed on trees and shrubs are now established in the United States with significant economic impacts.

Most non-native, and potentially invasive, species are prevented from entering this country by USDA-APHIS port inspections; however, due to the volume and cryptic nature of many of these species, some escape detection and become established. The early detection and eradication of an invasive species, either before it becomes established, or before populations increase, is critical to limiting their impacts.

In Maryland, a network of regulations, inspections and surveys is already in place to detect the introduction of an invasive species. The Maryland Department of Agriculture, Plant Protection and Weed Management Section conducts inspections of nursery stock entering the State, as well as systematic surveys through the Cooperative Agricultural Pest Survey program. The Maryland Department of Agriculture, Forest Pest Management Section conducts annual, systematic surveys in forested areas through the Cooperative Forest Health Program and the Forest Health Monitoring program. These programs work closely with the Maryland Department of Natural Resources, Maryland Forest Service and the public to recognize and report new forest pest problems in Maryland.