by Bob Mount
The Endangered Species Act of 1973, signed into law by President Richard Nixon requires conservation of threatened or endangered species throughout all or a significant portion of their ranges and conservation of the ecosystems they depend on. Numerous aquatic snails and mussels that were formerly abundant in Alabama streams are now extinct or are listed as threatened or endangered by the U. S. Fish and Wildlife Service. Yet comparably few such insects are on the list. The Xerces Society, an organization dedicated to conserving harmless and often beneficial insects, notes that only four percent of the listed animals are insects, whereas 17.9 percent of vertebrate animals in the U.S. are listed. The Society points out that 72 percent of the world’s animals are insects and concludes that on this basis at least 29 percent of the insects in the U.S. should be on the list.
If the Endangered Species Act was rigidly enforced by the USFWS, at least two insects that once were common throughout Alabama and probably in all other lower southeastern states, but have now virtually if not completely disappeared are the common black tumblebug and the catalpa sphinx moth. The larvae of the latter feed on the leaves of catalpa trees, and were commonly called “catalpa worms.”
The tumblebugs, “Canthus vigilans” were valuable in dispersing piles of cow manure in pastures, which if left intact, provided breeding sites for blood-sucking horn flies that aggravated the cattle. It is widely believed and has been documented that the chemical, ivermectin, when present in the manure is toxic to tumblebugs. The chemical is injected into the cattle to control internal parasites, and winds up in the manure.
The disappearance of catalpa worm, which were widely used to bait fishing hooks, was doubtless the result of the presence of imported red imported fire ants. When the larvae dropped to the ground to burrow and enter the pupal stage, they would be attacked, killed, and eaten by the ants. it’s been several decades since I last saw a catalpa worm. In one of my columns I asked my readers to let me know if, when, and where anyone of them had seen a catalpa worm in recent years. I received no responses. Should Canthus vigilans and the catalpa sphinx moth be listed as “endangered?” Obviously they should be.
One of my three degrees was in entomology, and I have been interested in insects and other critters since my youth. In addition to the aforementioned, I have noticed sharp declines in many other insects over the years. The large bristly robber flies, Family Asilidae, are now rarely seen. We called them “fly in front of you bugs” because when we were walking along a path, when one was encountered it would take flight and land a few yards away. This would be repeated time and time again. Other insects doing likewise were tiger beetles, which I seldom see anymore. The larvae of tiger beetles live in round holes, and can be “fished” out using grass stems. They had humps on their backs, and when pulled from their holes and aggravated they would attempt to bite their captors and spit “tobacco juice” from their mouths.
Surely, competent observers have noticed that fewer large grasshoppers are present now in suitable habitats than they once were. The absence of one species is exemplary. It is, or was, the fairly large brown hopper conspicuous because of its black and yellow wings when in flight. I sometimes wonder if a shortage of large grasshoppers has not contributed to the plight of the Loggerhead Shrike, known by many as “butcher bird,” which is now rarely seen. This bird fed largely on large grasshoppers, and stored excessive numbers caught by impaling them on thorns of thorny shrubs or on barbs of barbed wire fences. Another bird that once bred in these parts, but no longer does, is the Southeastern Kestrel, or sparrow hawk. Its food consisted largely of grasshoppers. One has to wonder if a hopper shortage has had anything to do with the Kestrels’ abandoning our area as a place to breed.
Of course, as every observer is aware, no longer do Eastern Meadowlarks breed in these parts, nor do Nighthawks, except for a pair or two that nest on gravel roofs. Nor do we have any more breeding Bobwhite Quail. All these ground-nesters have succumbed to predation by fire ants.
Speaking of animals that should be considered for listing as T or E species, two mammals come to mind as having virtually having disappeared from a “significant portion” of their respective ranges, the spotted skunk and the striped skunk. Not too long ago, the smell of a skunk was a nocturnal ambient odor detectable in nearly every rural area of central and southern Alabama. It’s been quite a while since I have seen or smelled a skunk. To me, the smell of a skunk was a pleasant reminder of the times I spent possum and coon hunting in South Georgia.
Bob Mount is a Professor Emeritus with the Department of Zoology and Entomology at Auburn University. He is also chairman of the Opelika Order of Geezers, well-known local think tank and political clearing house. He writes about birds, snakes, turtles, bugs and assorted conservation topics.