Spraying for Ipps Beetle - Ask Extension
Is it necessary to spray for the IPPS ENGRAVER BEETLE for mature Norway Spruce or Blue spruce trees in the city of Denver (Park Hill zip code 80220)? ...
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Spraying for Ipps Beetle #558821
Asked May 06, 2019, 2:39 PM EDT
Is it necessary to spray for the IPPS ENGRAVER BEETLE for mature Norway Spruce or Blue spruce trees in the city of Denver (Park Hill zip code 80220)? We have not seen any or heard of any tress that have it here but have had the trees sprayed 2 times a summer for the past 2 years at a cost of $160-190 a year and wonder if this a necessary prevention?
Thank You,
Kathy Ambruso
Thank You,
Kathy Ambruso
Denver County Colorado
Expert Response
Kathy,
Frustratingly, there is no sure answer. Spraying spruce in landscape settings reduces the incidence of an Ips attack but there is no way to know whether the spruce would have been fine without spraying.
The CSU Extension fact sheet says one indicator that can help decide whether to spray or not spray is observing whether other spruce in the area have been attacked (https://extension.colostate.edu/topic-areas/insects/ips-beetles-5-558/ ).
In your Park Hill 80220 zip, I happen to know of a mature blue spruce that just came down in April because of beetle kill (NE corner of Montview and Ivanhoe). That tree began dropping needles last summer even though the homeowner had been getting the tree professionally sprayed annually. Based on that experience, we know that there are Ips beetles in the neighborhood. It's a judgement call about how important your spruce is to your landscape and how much risk you want to take.
Frustratingly, there is no sure answer. Spraying spruce in landscape settings reduces the incidence of an Ips attack but there is no way to know whether the spruce would have been fine without spraying.
The CSU Extension fact sheet says one indicator that can help decide whether to spray or not spray is observing whether other spruce in the area have been attacked (https://extension.colostate.edu/topic-areas/insects/ips-beetles-5-558/ ).
In your Park Hill 80220 zip, I happen to know of a mature blue spruce that just came down in April because of beetle kill (NE corner of Montview and Ivanhoe). That tree began dropping needles last summer even though the homeowner had been getting the tree professionally sprayed annually. Based on that experience, we know that there are Ips beetles in the neighborhood. It's a judgement call about how important your spruce is to your landscape and how much risk you want to take.
