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Issue 3, May 9, 2016

Emerald Ash Borer Adult Emergence Beginning

We generally think of Memorial Day as the time of year to begin thinking about emerald ash borer emergence (Figure 1). Given the warm weather this spring, the southern part of Illinois has already reached the accumulated degree days to signal adult emergence (Table 1). This was confirmed last week with adult emergence confirmed in Marion.  Wayne County, Missouri also confirmed adult emergence last week. Given the degree day predictions in the table below, the southern half of the state may begin observing some initial emergence in the next two weeks. Peak activity is expected to occur when degree day accumulations reach 1000.

Emerald ash borer has been confirmed in 60 of the state's 102 counties (Figure 2). While it is believed to be widespread, residents are still urged to keep an eye on their ash trees, assess their health, and report infestations in previously unconfirmed areas. Remember, potentially infested trees may have D-shaped exit holes on the trunk and branches, reduced foliage/dieback, and epicormics shoots.

It is also important to note that Illinois recently lifted its internal EAB quarantine. By deregulating, the state of Illinois will no longer restrict the movement of any cut, non-coniferous firewood within the state. Scott Schirmer, State Plant Regulatory Officer is the Illinois Department of Agriculture shared the following: "Though the Illinois Department of Agriculture (IDOA) no longer has a quarantine and internal regulations surrounding EAB, they are still tracking its movement and would like to be notified of new county or town finds.  The Department still encourages Illinois residents to not move firewood other than as needed locally, and to be aware that Federal regulations still exist regarding out of state movement of ash material(s).  If there is ever a question about the legality of moving these materials, please contact the IDOA, USDA, or your local U of I extension office.  Property owners and managers are still advised to monitor their ash trees and remove them before they become hazardous."

Figure 1. Emerald ash borer adult emerging (Photo courtesy Vincent Shoemaker, USDA APHIS PPQ).