Meet the beetles: Southern Pine Beetle

The Southern Pine Beetle is not a new pest.  In 1912 at the Second Annual Convention of the North Carolina Forestry Association, E. B. Mason stood before the convention and said:

I do not think it necessary for me to dwell on the seriousness of the situation in regard to the Southern pine beetle.  There is not a man here who has not seen the appalling amount of dead pine.”

The beetle, he said, had been in the South for at least 40 years already.  Indeed, SPB is native to the southern United States, and has been frustrating pine timber producers for over a hundred years.

For this reason, we know much more than you might expect about the life of a little beetle named Dendroctonus frontalis (that’s the Southern Pine Beetle if you weren’t following along).  Even in 1912, Mr. Mason knew much of the beetle’s life history.  He describes how the beetle bores into pine trees, carves galleries, and lays eggs beneath the bark, girdling and killing the tree, how the eggs become “little grubs” who feed in the “inner bark” for some time before they “change into beetles with wings,” and finally how these beetles bore back out of the tree and fly away towards the next unfortunate pine.

A callow adult, or a beetle nearing maturity, almost prepared to leave its birth tree.

While tremendous advances in our understanding of the Southern Pine Beetle have been made over the last decade and continue to be made even now, Mr. Mason’s central story is essentially unchanged, though the wording is different.  Fly is now disperse, little grubs are now larvae, and inner bark is now phloem.  One exception is that girdling and killing the tree has now become there are a few theories on what exactly causes the tree to die(but this is a story for another day).

Note that this photo was staged and that the beetle is quite dead (just to be clear).

That said, while Mr. Mason got the story right, he missed plenty of detail.  And who could blame him, when the details missed are microscopic mites, a host of insect predators and competitors, and several species of fungi.  All of these interacting pieces come together to form a complex web of activity.  But at its center is one 3-millimeter-long beetle with little clubbed antennae, who lands on a pine tree, walks clumsily to a crevice, and begins to chew its way toward its home beneath the bark.

This was a very brief introduction to the SPB, but more details will be trickling out in the weeks to come.  And if you’re really aching to know more, try this in depth resource from the Forest Service:

http://www.srs.fs.usda.gov/pubs/gtr/gtr_srs140/gtr_srs140.pdf

Advertisements

One thought on “Meet the beetles: Southern Pine Beetle

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s