Monday, July 6, 2015

Phenology: Katydids, Moths, Flowers

Last time I was here, a week ago, the katydids I heard on the way home were startling phenology news. Katydids are active during the last half of summer. In Virginia they're supposed to start their "discussion" ("Katy did!"--"Katy didn't!") twelve weeks before the first frost, rather than six weeks, as has been claimed in the North...but, either way, they're not normally heard in June. 

By now the "debate" is at what will probably be its loudest, as katydid "discussions" are really noises made by young unmated males hoping to attract females, most of which goes on during the week or two after the insects mature. A few unlucky or ambitious little guys will go on calling, here and there, until frost...but this weekend, while humans were celebrating the Fourth of July in town, in the woods the katydids were really carrying on.

Temperatures have been mild, even cool, all week. Weather has been particularly inconvenient as we've caught and apparently held on to the edge of another storm system. The sun will peek out for an hour or two, things begin to dry out, then another half-inch or inch of rain will be dumped on us during the next half-hour. This kind of weather tends to make humans grumpy. Independence Day celebrations, and even my extended family's traditional annual gathering on the Saturday nearest to the Fourth of July (hello?), were scantly attended.

For those who've asked, Grandma Bonnie Peters has been fit as a fiddle, even doing a day job in addition to staying with a paraplegic patient at night; it was her car that couldn't make it to the party. Between jobs, choir, grandmothering, and worrying her children she'd forgotten to take it in for its annual inspection. The car passed inspection and she went back to work today.

I'm seeing about the same mix of wild flowers I saw last week; two more isolated sweet peas were in bloom yesterday. My privet hedge still has unopened flower buds. During last winter's Big Freeze it lost its leaves; privet rarely loses all its leaves at one time, and, although it's recovered from similar shocks before, the effort of recovering has prevented the hedge from becoming a beautiful mass of fragrant blooms. Perhaps someone out there knows whether it's better for the shrubs to be pruned, anyway, and not waste any more resources trying to revive old growth, or be allowed to run wild this summer.

Earlier this spring I didn't see a lot of butterflies or moths, but populations seem to be recovering by now. In the past week I've seen Tiger Swallowtails, Spring Azures, Wood Nymphs, Coppers, Painted Ladies, and a sassy Sulphur butterfly literally leaped up and hit me in the face. I've not seen a Tuliptree Beauty or Haploidea bipuncta at the Cat Sanctuary yet this year. The whole tiger moth family seem to have been affected by the Big Freeze.

Some smaller Geometrid moths that live in the black walnut trees along the road have declared my office a nightclub and been scent-tagging me for advertising purposes. Moths have little in the way of brains, and what they do perceive hardly seems to overlap at all with what humans perceive, so it can surprise humans that purposes can occasionally be discerned in moths' behavior. Basically what moths want to do is find mates. (Flying around and into sources of light probably expresses confusion--they're wired to navigate by observing stars.) Moths can mate only with their own species; what humans see as tail ends are tiny, complicated anatomical structures that are even more diverse than the patterns on moths' wings, such that the only way humans can identify some species is by studying their tail ends under a microscope. So the animals rely on scent to find mates. Humans don't even smell most of these scents. We see moths flying around, touching, and clinging to specific places for no reason we can perceive. Usually this is because a moth of their species, of the opposite sex, has alighted there, and now one or more prospective mates are trying to find her or him. This can become quite annoying, especially to those who've tried to scent-trap nuisance moths, got the scent of the female moth on their skin, and found themselves in the middle of a cloud of eager male moths. (Bothersome as being searched by moths is, being "raped" by moths would undoubtedly be more so if it were physically possible.) So for the past week or two these moths have been swooning ecstatically over my home computer screen when I write at night...sometimes it's almost bad enough to make me turn off the computer. All the windows have screens. No window screen means any more to any self-respecting Geometrid moth than it does to a tiger mosquito.

So which moths are these? I had a field guide and looked them up, years ago. They're large enough and common enough to be near the beginning of the list of Geometridae in the field guide. They've even been assigned an English name...but it's not a common name in the sense of being commonly used. The caterpillars are commonly called inchworms, and the moths are commonly called light moths. By now I've forgotten their official Latin name. If I were using a more efficient computer than the Sickly Snail I could look them up online.