Are Alien Invaders All Bad?

Call them what you will, alien invaders, invasive species, or just aliens, these ecological-niche invaders are increasingly present in ecosystems on land and in water, and increasingly difficult to eradicate because they always seem to thrive, even when displaced, and frequently feed on – or otherwise eradicate – native populations.

In the animal kingdom, invasive species include the brown tree snake in Australia, the cane toad in S. America, the European starling in the U.S., and the Eurasian wild boar, also in the U.S., though its introduction almost predates occupation and probably doesn’t count (unless you’re facing one down in some Louisiana swamp).

In the world of bugs, the African honeybee comes immediately to mind because of its aggressive tendencies and also because of the U.S. decline of European honeybee populations due to varroa mites (or cell phone towers). This, of course, diverts attention from the Asian ladybug (also known as a home invader in autumn), the Caribbean fruit fly (just as its name suggests, including the apple in your hand), the European bark beetle (Dutch elm disease) and the Gypsy moth, ostensibly introduced to make silk, until scientists discovered it was better at eating than working. In fact, Gypsy moths will eat the leaves of almost every species of tree growing in the U.S.

Among aquatic invaders, we have a number of mussels, including the zebra mussel of the Great Lakes, native to the Caspian Sea region of Asia, and quagga mussels from the Ukraine. We also have the Asian carp, which – like the starling – seems to be at home everywhere. Aquatic weeds feature milfoil, which is even more adaptable than the carp, and loosestrife, which, while not actually aquatic, likes to keep its feet wet in marshes and shallow ponds, but will go anywhere it isn’t prevented and shoulders out all other greenery with obnoxious self-aggrandizement.

I know they are invaders. I know they take over regional ecologies and are darn near impossible to eradicate. I know that the U.S. alone has 6,000 introduced species (excluding microbes) that are thriving without human assistance. I know eradicating them costs at least $138 billion per year.

In spite of that, I’m going to leap to their defense. At least, to the defense of some of these invaders, which are not only quite pretty (loosestrife and milfoil), but seem to have the ability (oft lacking in native species) to not only survive but thrive in global warming conditions that are accelerating much faster than predicted. I’m sure the environmental community is going to denounce me roundly for my unorthodox stance, but they say strength comes through adversity, so bring it on.

I’d prefer robins, but if things get really bad I will settle for starlings. I prefer cattails and rushes, but when lake levels fall close to nonexistent, milfoil may be the only greenery able to survive in noxious waters. I also prefer walleye, but carp are edible if highly seasoned, and I would much prefer my European honeybees, but African versions also produce honey and can be managed by the very cautious. I eat clams, but if I were starving I could easily down a zebra mussel with a little salt and lemon. We’re talking exigencies here, and the 21st century may boil down to nothing but exigency in terms of food and other resources.

Perhaps, in a warming world, with regional ecologies collapsing left and right from pollution and overuse, these aliens are Nature’s way of preserving life, however ugly, obnoxious and creepy. I’d rather have an Asian lady beetle roaming my cucumber vines than suddenly discover there were no insects at all. Because no insects will indicate the final collapse of all of earth’s ecosystems and I don’t want to live to see that happen. Do you? More important, I’m no longer sure, having made such a mess of things, we humans actually have a choice, so perhaps we should let Nature make a few decisions.


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