July 13, 2011 8 Comments
Very rough translation: They loved us, then left us. (the cicadas, that is.)¹
¹ Guest blogger’s subtext — Maybe if I dazzle the readers with a title in the colorful language of Pompeiian graffiti, they’ll forgive me for not posting pictures as beautiful as Ted’s. Well, anyway…
On this year’s US Independence Day, we in the St. Louis area were able to proclaim our freedom from the 5-week-long din of cicadas, or so the TV “news” reporters would have us believe. For me, it was more of a return to the dominance of human-made noise; the faint drone of a distant highway, the monotone roar of a neighbor’s lawn mower, the repetitively plosive engine of one of the many diesel pickups that float by, with the CD player’s bass thumping at an almost certainly hearing-damaging decibel level.
I started my celebration early in the day, by doing some gardening and rearranging in the yard. Moving a pile of concrete paving stones, I reached the bottom one and lifted it, and was greeted with a view of abandoned nymphal emergence burrows made by just a few of the many thousands of periodical cicadas that graced my yard with their presence this year. The burrows were already showing wear at the edges in their disuse. A little later later in the morning, I heard the whoooooooa-ooh of a last, lone Magicicada tredecim male from the hackberry tree—first one call, then another, then no more. But nature’s course proceeds, and as afternoon drifted into evening, I was pleased to hear the first of the dogday, or annual, cicadas of the genus Tibicen. These are not truly annual; They emerge every year, but actually take several years—4 or 5, it is said—to develop from egg to adult.
The four Magicicada species that can be found in the St. Louis area, near the western edge of Periodical Cicada Brood XIX (a.k.a. the Great Southern Brood), are famous for their intermittent emergence as adults, every 13 years. (Life spans of 17 years occur in three, more northern species that do not occur in the St. Louis area). In fact, during years to either side of the two emergences of Brood XIX that I’ve experienced since moving to this area 24 years ago, I have always heard, and if really lucky, seen a few, one or two years before and after the “scheduled” emergence. But, the vast majority stick to the plan of feeding on the xylem sap of tree roots as subterranean, tan-colored nymphs for 13 seasons before coming out of the ground, then molting to the ever-so-buggy-looking, winged, black insects with red eyes and wing veins, that “freak everyone out” during their mass emergences.
The mass emergence is all about reproduction, the successful transmission of genes to the next generation—you know, Darwinian fitness. When a female happens to “like” the song of a particular male, she flies to him, then is courted a for a bit with a different song, before “succumbing to his charms”. Mating typically takes place up in trees. But, being amoral creatures of little brain or scruples, they may choose indelicately to copulate on a porch rail or other such public place.
Consumed with sex, the adults don’t eat much, but occasionally one sees a cicada poking its proboscis into some soft plant tissue for a drink of sap (clearly exhibiting the relationship of these large insects to those smaller sap-feeders, the aphids and such). A little sap-drinking does little damage to plants, but the insertion of eggs by the mated females into small twigs of woody plants can do quite a bit of “natural pruning”. This would be more of a concern if it happened every year, I suppose, but it really also does little damage in the long run, especially on a mature tree. Still, I would have appreciated it they hadn’t found my recently planted black gum tree such an attractive oviposition site.
But I don’t begrudge them this. I miss their mass serenade. I treasure the remembered sight of a corpulent hairy woodpecker muddying itself to pull one nymph after another from rain saturated ground. I delighted in seeing a surprisingly chubby chipmunk perched fearlessly on an exposed root as it munched a cicada whose wings never properly expanded. Perhaps best of all was watching a red-shouldered hawk clumsily hop about on the lawn to snarf up cicadas that weakly fluttered to the ground. But now, the periodical cicadas are, till May of 2024, mere shells of their former selves.
To end on a pretty note, here’s a gaudy cicada that was attracted to lights of the scientific station’s laboratory building in Yasuní National Park, Ecuador, and obligingly posed for a photo on the windowsill.
Copyright © James Trager 2011