I know it’s officially fall because brown marmorated stink bugs have been swarming on the outside of my house. Emerging research indicates that the bugs’ search for winter quarters seems to peak around the autumnal equinox (Sept. 23), triggered by waning daylight.
Other invertebrates were also taking advantage of the warm, sunny weather before last week’s rain. When I spotted a pair of eastern tiger swallowtail butterfly wings (sans body) hanging from one of my smooth blue asters, I was sure a predator was afoot. The next day I found the culprit — a female Chinese mantis — finishing off the last of another eastern tiger swallowtail that had come by to feed on the asters’ nectar.
Mantis activity usually picks up this time of year, when females lay their eggs — in a foamy, brown egg sack (ootheca) that hardens and protect the eggs over winter. Searching for food, and likely mates, several females have been visiting all the last blooms in my yard, which are also attracting hordes of the various invertebrates the mantises’ prey on.
One day, after hearing the loud buzzing on my asters, I thought a colony of honeybees had also stopped by to feed on their nectar. On closer inspection, I found that the sound came from dozens of hoverflies. These flies mimic bees and wasps, right down to the buzz, created by the rapid flapping of their wings.
The hoverflies had black bodies about the length and thickness of a honeybee, with yellow stripes. As their name implies, they generally hover when they feed, so were hard to ID until I later looked at photos of them that I’d managed to grab. The photos showed that the insects were indeed Diptera (in the fly and mosquito insect order), not Hymenoptera (the order that includes bees and wasps): they had two wings, not four, and their antennae were straight, not bent at a joint in the middle. Knowing the many hoverfly species are tough to sort out, my best guess is that the ones feeding on the asters are in the large Surphus (flower fly) genus.
Despite all the invertebrates in my yard and the forest it borders, I’ve often lamented not finding any butterfly caterpillars since I moved here five years ago. Moth caterpillars and cocoons are everywhere up here in the fall, and many butterfly species, including spicebush swallowtails, visit my gardens during the summer, but I’ve found no butterfly larvae. This summer, I’ve been especially diligent about checking for caterpillars on the spicebush that lines one path through the woods, to no avail.
Then one day recently, I spotted on the gray concrete foundation of my house what looked like a slug dressed up for a fancy dress ball in a bright-green, bejeweled costume. It took a couple of seconds for it to sink in that I was looking at a pupa of a spicebush swallowtail. Knowing that several moth cocoons had recently been nabbed by predators off the sides of the house, I decided to try to overwinter the pupa in a glass jar in a sheltered area on my deck, with the hope of seeing the adult butterfly emerge in the spring.
While our fall rains, usually linked to storm systems moving north up the Atlantic, can occasionally be damaging in Virginia’s interior, they are rarely as catastrophic what South Carolina is experiencing after Hurricane Joaquin and another low-pressure system butted up against each other last week. And our fall rains do have an upside — most significantly they recharge our groundwater, often after summer drought.
And we are not the only organisms that benefit from these rains. Amphibians, for example, are most likely to be on the move when it rains, even into early fall. Driving through the hollow on warm, wet evenings or early mornings recently, I’ve seen spring peepers making their way across the road; some may already be looking for overwintering spots under logs and under loose bark on trees. And, in a walk through the woods near my house, the crimson coloring of a fairly large red eft — the juvenile, terrestrial form of the red-spotted newt — stood out on the forest floor, the only bright spot on a dark, soggy trail.
Mushrooms have also been loving the wet weather. Blooms of several fall species have been popping up all over my lawn, including purple ones that I think, after looking at my references, are blewits (Clitocybe nuda), and tiny white ones, with spines, that I’m pretty sure are “clustered spiny puffballs” (Lycoperdon marginatum). I’ve had no luck in trying to ID another lovely, smooth mushroom that is white with a beige center.
With some birds already migrating south, the flood of ruby-throated hummingbirds at my feeders had slowed to a trickle by the third week in September. The currently sporadic visitors are likely migrating through from the north. An eastern phoebe also showed briefly this week, gleaning insects off the lawn — the first phoebe I’ve seen for at least a month — and moved on.
When the rain ended this week, the cricket chorus returned, with chirps and trills of several species enlivening the night. I’ve only been hearing katydids during the day down by the lower ponds, where it’s generally warmer.
On a sunny but relatively cool day this week, I saw an eastern rat snake (aka black snack) that had tried to cross U.S. 211, or maybe just warm itself up on the road’s heat-absorbing surface. Whatever the reason, it had not ended well for the snake.
Early this week I also found my first black-legged (deer) tick since late spring, crawling across my arm. In the Northeast, the adults start to become abundant early in October and will “remain active through the winter as long as the temperatures are above freezing and the ground is not frozen or covered by snow,” according TickEncounter Resource Center — so something to look forward to as fall progresses.
© 2015 Pam Owen