Home Is Where Your Trees Are

Pests And Parasites. Part 1

Within the wonderful world of trees lies another world - that of the organisms which harbor in trees as pests and parasites. Of these there is no end in numbers or variety. New home owners are scarcely to be blamed for becoming dismayed, as they often do, upon encountering one invader after another for the first time. This writer's counsel to clients undergoing such baptism has always been: Cheer up, few kinds of attack on trees are fatal. Study of the trees' foes-learning to anticipate and counteract them - is a sporting proposition in itself. You may lose a few skirmishes, but there is a great deal that you yourself can do to win this war. Only occasionally will an owner, particularly of young trees, have to call in a tree-service task force.

The trees' invaders are from two kingdoms - the animal and the vegetable. The former are insects (and one bird) ranging from king-size larvae of the big moths down to microscopic mites, mini-wasps, and scale organisms no bigger than a pin point. The vegetable hordes are fungi, bacteria, and viruses. These are all primitive plant forms, but there is one plant parasite that is anything but primitive except in its role, assigned by mankind, as a love symbol. This is mistletoe, one of the deadliest invaders of all. Mistletoe might well be spelled "missile toe," for its first tiny rootlets have the power to insinuate themselves into the host tree's living tissues like the fangs of a vampire.

Its pallid, waxy berries, resembling seed pearls, are carried by birds and dropped into bark crevices where they germinate under protection of their own gum.(Curiously, both mistletoe and the other Christmas evergreen, holly, yield viscous exudate called "lime" (from the Latin "limere," to smear), which was used immemorially by men to snare birds.) Mistletoe cannot live in soil but must steal its nourishment from a host tree's sap veins. Where it fastens on, grotesque swellings ensue and the host's deformed members writhe away from the vampire as if in horror. No amount of chopping-out short of limb amputation will eradicate the mature bushes. Fortunately for trees, and for the human kissing custom, and for Oklahoma whose State "flower" mistletoe is, the deaths it inflicts are slow and painless. Its glaucous clumps aloft even confer a macabre beauty upon the elms, hackberries, walnuts, gums, pecans, mesquites, and (rarely) oaks which it reduces to skeletons.