WELCOME	Identification of Stages of EAB Decline & Whether Treatment is Warranted David L. Roberts, Ph.D. Michigan State University Extension
Emerald Ash Borer larval injury may predispose trees to attack by other insects and diseases.  Such trees may become so weakened that they break off in windstorms because their structural integrity has been compromised.  (Fig. 42)	Pictorial Identification - Stages of Ash Decline Return to:   EAB Homepage

Identification of Stages of Emerald Ash Borer (EAB) Decline
and
Whether Treatment is Warranted

Should I treat my ash with a pesticide?

    Whether one should treat their ash with a pesticide depends on a variety of factors. Are the ash actually affected by the Emerald Ash Borer and not some other malady?  What is the value of the ash and will it truly help the trees?  How much money am I willing to put into maintaining the ash?  Perhaps the greatest difficulty is determining whether my trees will respond to the chemical treatments or are the already too far advanced in decline to recover.

     Following are some stages of the Emerald Ash Borer decline and some advice on whether I believe trees are worth the risk of trying to save or whether there is a chance of recovery.  Initially in 2002, we believed that trees exhibiting up to 40-50% decline (Stage 3) could be saved. We now know we were wildly optimistic because there is much more tunneling beneath the bark than is readily apparent by decline symptoms. The extensive tunneling prevents the movement of chemical control agents from moving in the tree and hence, insect continue to feed, eventually compromising the health of the tree. We advise that ash owners who want to save their trees should have insecticide applications made preventatively (no EAB infestation) or with no more than 10-20% canopy loss (Stage 1 to Stage 2). We anticipate best result will be obtained with preventative treatments.

	Stage #1:  This tree is apparently healthy, but is actually already being attacked by the EAB. We believe this tree should respond to chemical treatment. Further, we believe that trees treated preventatively (before infestation) have the best chance of survival. This tree would warrant treatment particularly if it grows in an area where there is abundant EAB activity. (Fig. 43)
	Stage #2:  This trees shows definite initial symptoms of the EAB injury.  This tree may or may not respond  to chemical and other cultural inputs. Diagnose the problem early! We suspect trees beyond 10-20% canopy dieback cannot be saved. (Fig. 44)
	Stage #3:  Intermediate decline indicates more activity by the EAB than what is really evident. We doubt that this tree can be saved. In fact we doubt that trees with more than 20% foliage (canopy) loss cannot be salvaged. (Fig. 45)
	Stage #4:   Probably way too advanced to be salvaged as a viable tree. Removal and proper disposal is probably best. (Fig. 46) Note, tree in background near townhouse is definitely a Stage #5.
	Stage #5:  Dead or near death. Proper removal and disposal is advised. Trees in Stages #3, #4 and #5 harbor many insects and can act as “typhoid marys” to nearby ash trees. (Fig. 47)
Winter Study of Homeowner's Ash Trees	Hot Link * Identification of Ash: Ash Tree IDentification Guide
Fraxinus - Ash  OSU Bulletin   White Ash Identification   Green Ash Identification   Ash Trees Leaves/Bark/Twigs - ISUE    Alternative Selections for Problems in Tree Species .pdf	EAB Site Navigation:   EAB Homepage   Photo Gallery I - EAB   Photo Gallery II - EAB & Ash Trees in Decline    Ash Tree Decline Research History & Management   Links   EAB: Winter Management Through Sanitation    How well do Insecticides work for EAB?    Media Files

 

	David L. Roberts, Ph.D.    Michigan State University Extension Southeast    28115 Meadowbrook Rd., Novi, MI  48377-3128   Campus:      Michigan State University     B17 Plant & Soil Sciences     East Lansing, MI  48824-1359    For comments or questions email:  robertsd@msu.edu
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