OH BUGS!

Don't hold the lowly insect in contempt! They represent a vital force that man, in his many fields of endeaver, has learned to respect for while many are beneficial and others are entirely harmless many species among the thousands are very destructive to man's enterprises -- even to human life itself!

Last spring here in Mt. Rainier Nat'l Park the needles of the White Pine began burning brown as if they were drying up from lack of moisture. And that's just what was happening although the season was possessed of more than usual rainfall. The cause of this "drought" lay in the working of many tiny insects of the beetle group. Not more than a fifth of an inch long they were, but their strength lay in their numbers. Those beetles, which are known scientifically by the formidable term of Dendroctinus monticolae (perhaps we had better refer to them as the Mountain Pine Beetle) construct numerous tunnels in the growing or cambium tissues just beneath the bark of the tree and in that manner girdle the trunk and prevent the food materials from passing to the foliage and branches of the crown.

In the drawings below the life history of one of these beetles is pictures. It must pass through four different stages before it reaches the adult or mature beetle and each stage is very different in general appearance. This series of processes (also characteristic of the well known butterfly or moth whose life history is also pictured) is called "complete" metamorphosis. The beetle attacks the tree in the fall, bores through the bark to the favored tissue and constructs a long galery parallel to the grain of the wood, depositing the eggs in tiny niches along the side as it proceeds upward. In a few days these eggs hatch into grub-like bodies called larvae and those, in turn, gnaw their own individual tunnels at right angles to the main galery which their parents constructed. These larval galeries, if the beetles are present in large enough numbers, will eventually circle the trunk, girdling it and causing the death of the tree. The third or pupal stage, in the case of the Mountain Pine Beetle, is passed late in the spring. At this time it goes through the final change and emerges in June as a full fleged adult beetle capable of attacking other trees.

Two groups of well known but very destructive insects -- (1) the beetles and (2) the moths and butterflies.

Naturally the process is not as simple as it sounds. The prospective beetle finds many pitfalls along the way. Birds seek him, other insects -- the parasites and predators -- prey upon him in one way or another and unfavorable conditions of all kinds tend to reduce his numbers so that a great percentage of them never reach maturity. Happily too, for if all insects completed their life cycle they would soon be present in such numbers that a great deal more damage would result from their operations than is the case now. In regard to the forest we think of fire as the arch enemy. As a matter of fact, while fire consumes a great amount of timber annually and care with it in the woods should be exercised at all times, these silent tree killers, unpossessed of any spectacular display, pursue their work unnoticed by the average person and destroy more timber than fire does.

Exclusive of the predators and parasites there are other insects that perform a valuable service to the forest. These are the species that prefer dead and down timber -- thus aiding in the disintegration of forest litter. And so from the seedling to the dead log the tree is subject to insect attack. And the attacking insects are themselves possessed of enemies as well. Which brings to mind the following verse; "So naturalists observe a flea Hath smaller fleas that on him prey; And these hath smaller fleas to bite 'em And so proceed -- and infinitum."

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