What kind of naturalist am I, sitting here all day at this computer? That's what I asked myself in frustration this morning before I headed out with a bottle of water and my camera to see what I could find. A few minutes later, I pulled into the parking area of Jackson Forest, a little piece of preserved land that may be all that remains when developers move on to destroy another Jersey community. But that's another story.I wasn't long down the trail when I started to see odd little gatherings on the trunks of oak trees. Almost like little ghost towns left behind on the bark and under leaves - telltale signs of gypsy moths. It's August, prime egg laying season and the trees were covered with yellowish masses and spent pupal cases.
The eggs will develop for a month or so, and larva will be fully formed then. But rather than emerge in time for fall, when food would be scarce, the clever gypsy moth caterpillar suspends its animation (diapause) and waits through winter. In spring, as temperatures start to rise, the larva reawakens and emerges in time to eat the newly opened leaves.
Next in its life cycle comes a behavior that terrified me in my childhood - ballooning. The new caterpillars climb to the top of the tree from which they hatched, cast a long silky thread, and wait for a breeze to carry it off, often as far as 150 yards. When I was 6 or so, there was a particularly bad gypsy moth infestation and I remember seeing hundreds of caterpillars descending from the tree tops in my grandmother's backyard. They were so numerous we had to dash from the car to the house to keep from getting creepy crawlies in our hair.
But that was then, and this is now. Back in late May, the planes flew all morning long, just over the powerlines and houses, spraying to keep the gypsy moths at bay. They stopped for an hour or so when the schoolchildren were at the bus stops in the morning. I guess big people don't matter as much. Since reading Silent Spring back in college, I've tended toward skepticism when the government declares something "safe."Anyway, once the caterpillars land on firm ground (or leaf), they begin a 5-6 week feeding frenzy that can literally defoliate trees overnight. After molting 5-6 times and reaching full size, the cats find a quiet little place to rest, usually between ridges in the bark, and shed their skin a final time. Two weeks of stillness leads to the emergence of the adult gypsy moth.
At this point, there's nothing left to do but reproduce. Females, oddly, can't even fly. The males spend their afternoons flying in search of a mate. With only two weeks left to live, this is a frantic dating game at best. Once true love has been found and the marriage is consummated, the female lays a mass of eggs and covers them with buff colored hairs from her body. You can see egg masses, as well as pupal cases, in my photo (above, right). A well-nourished female may lay 600-1000 eggs in a single mass.
I guess the spraying over the years has helped controlled this exotic pest, since I can't remember another year like that from my childhood. Still, I can't help thinking it would be better to spray for developers - don't they destroy more forests per year than gypsy moths?
