It’s best to listen to this post in audio form – it’s only 6 minutes long- because you’ll hear a unique soundtrack of insects – the focus of this review. Just click on the title above to listen or download the MP3 file.

[clip from "The Sound of Light in Trees" by David Dunn]

In his best-selling book, "The Weather Makers," Tim Flannery writes:

"Among the most visible impacts of climate change anywhere on Earth, are those brought by the Spruce Bark Beetle. Over the past 15 years, it has killed some 40 million trees in Southern Alaska, more than any other insect in North America's recorded history.

Two hard winters are usually enough to control beetle numbers, but a run of mild winters in recent years has seen them rage out of control. The Spruce Budworm is another threat to the trees - the female budworms laying 50 percent more eggs at 77 degrees Fahrenheit, than at 59 degrees Fahrenheit."

end quote.

[The Weather Makers Audio Book, Disc 3 around 2:10]

Thanks to a new nature recording from EarthEar.com, we just tuned in to the intimate world of these tree killers, thriving unseen beneath the bark of our favorite conifers. It's a kind of music of mandibles and moving parts we don't yet understand. These are sounds humans have never heard before.

As a an artist recording soundscapes, David Dunn began to focus on the pinion pine, Pinus edulis, around his home in northern New Mexico. These striking dry-weather pines are dying in great numbers, and most of them may die off in the next few years. The culprit is the pinion Engraver Beetle, with the scientific name Ips confuses - just the size of a grain of rice. Like many other beetles and borers, in almost every part of the world, these insects attack damaged and stressed trees. They leave crazed trails in the wood, after the bark falls off the dead trees.

Until the last few years, wood beetles, budworms, and borers have been the cleanup crew of the weakest trees, as nature's design demands. They were limited by the weather, especially by winters cold enough to kill them under the bark. Now with milder winters, there is nothing to stop them. The conifers we grew up with are threatened and dying, and the public hardly knows about it. Life goes on in the cities while endless forests die off.

Possibly due to the stress of changing climate, weakening the trees, such beetles are threatening to wipe out whole forests of pines all along the Rocky Mountains. In British Columbia, Canada, the pine borer is already turning vast mountain valleys into a red funeral forest. Then the dead dry timber begins to burn, killing forests and its creatures.

Conifers are under attack in Arizona and California, including the classic ponderosa pines. As we've heard, the Spruce Bark Beetle in Alaska has already killed over 40 million trees.

If the temperature continues to rise, beetles may invade the five-needle pines higher in the mountains, killing off the jack pines of the Northern States and Canada. Oceans of dead pines. We can hardly conceive of it. Why aren't we mourning?

In the fascinating liner notes, David Dunn tells us:

"..a serious infestation of the high elevation conifers could substantially reduce the snow-fence effect (windrows of captured snow) that these trees provide in the conservation and distribution of water from the Rocky Mountains. Since the Rocky Mountains serve as headwaters for major river systems in North America, and the fact that most of their source water accumulates as winter snow, such tree loss may prove catastrophic."

Dunn captured these never-before-heard sounds by implanting numerous tiny microphones right into the wood of the trees. Our ears, and regular microphones, would never pick it up.

We think that bugs under the bark of trees make noises for a variety of reasons. Perhaps sounds act as a spacing signal, just as Robins will sing in a tree to claim enough space for nesting and immediate feeding. The beetles and borers need an area to eat, without tunneling into other bugs. They may be sending other signals as well, regarding reproduction. We don't know.

Yet beetles don't have ears. Scientists suspect they hear through mechanical hair-like attachments that sense the vibrations we call sound.

The greater the infestation, the more sounds they make. Using this recording technique, we can discover beetle infestations before there are visible signs in the trees, and even before the chemical markers previously used studied in scientific research.

It is also possible that beetles hear tree distress signals, called cavitation events, to find which trees to attack. We don't know.

We do know that beetles don't act alone to kill the trees. Their bodies also carry a variety of fungi called "bluestain." It is this fungus which weaken the tree's vascular system, and leave the wood with a mild blue or purple stain. Some forest companies, encouraged by government to cut dead trees before they burn, have tried to market fungi stained wood as "Denim Pine." The stain does not affect the structural integrity of the wood, but buyers shy away from purple pine wood, and the market is flooded, as timber companies struggle to clear away entire watersheds of dead red trees. It's a bonanza of clear-cutting without any environmental protest. The forest is already dead, and we hope to stop the insect plague.

David Dunn hopes the art of beetleworld will help science develop a way to save the trees - from insects unleashed into previously immune forests, by climate change. His album of beetle sounds, titled "The Sound of Light in Trees," has just been released by Earthear.com.

When I first got the CD, I thought Jim Cummings and his crew have finally disappeared over the edge of nature recording. An hour of beetles "talking" and chewing? Where is the market for that?

But it's eerie to start the CD playing, and then find yourself half an hour later puttering at the computer, or some other chore, while the original "Beetles" move you along to their secret rhythms. It's a good background for conversation too.

More than a novelty, or a scientific tool, this recording does have art. When technology finally allows us to hear it, even the bugs make music.

Perhaps everything is musical, if we could only perceive it.