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25 year old ponderosa pines are dying #215689

Asked October 05, 2014, 5:39 PM EDT

I have several large ponderosa pines about 25 years old that appear to be suddenly dying. The bark is very crackled and I peeled some off. I found some little round black dots, some sap and what looks like an earwhig.
Is there some treatment I can give them?

Boulder County Colorado

Expert Response

Hello, It sounds like the insect could be the blackhorned pine borer, Callidium antennatum hesperum Casey. These beetles are commonly called long-horned beetles because of their long antennae. The adult is flattened, bright metallic blue, violet or bluish- black, and from 3/8 to 1/2 inch long. Adults appear in early spring and fly to host material where they deposit eggs beneath bark scales on dead trees or on cut wood that has seasoned over winter. The larvae feed in the phloem and outer sapwood making broad, meandering, intertwined tunnels in the wood and pushing large quantities of frass through small holes in the bark. Pupation occurs in the wood in long cells plugged with wads of fibrous frass. There is usually one generation per year. They generally will not attack a healthy tree but are attracted to dead, dying, diseased, or stressed trees. Consequently, one of the control recommendations is to keep the tree in good condition by pruning out damaged wood and maintaining good cultural practices such as proper watering and fertilization. In order to be sure, you would need to first identify the "earwhig" type insect you saw under the bark. There are many photos of the blackhorned pine borer online, if you'd like to give it a try. Otherwise, you could bring some of the insects into our office and we can I.D. them for you. If you're a Boulder County resident, the fee is $7. If not, the fee is $11. If you plan to do this, please put the insects in a small jar with rubbing alcohol so that they are not alive but are preserved. I hope that helps, Shere Colorado Master Gardener Volunteer
An Ask Extension Expert Replied October 13, 2014, 11:26 AM EDT

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