Did you know there is a silk moth – one of the moths of the family Saturniidae – that belongs exclusively to Northern New England? Its natural range is entirely within Vermont, New Hampshire, Maine, and Massachusetts. It is a moth we truly can call our own, and we do: the New England buck moth (Hemileuca lucina).
This moth is diminutive in size compared to its relatives, which include the enchanting, pale-green luna moth. While the buck moth’s wingspan is no more than a couple of inches, it is just as lovely as the luna, with its translucent wings and tufts of red “fur” about its collar and at the tip of the male’s abdomen.
Its scientific name comes from the Latin: Hemi = half, leuca = white, lucina = translucent, for its translucent wings, which are half white. Its common name refers to the fact that it flies only in the autumn, when white-tailed bucks are starting to move. There is a very similar moth called, simply, “the buck moth” (H. maia), but it has a much larger range, opaque wings, and it flies earlier in the season.
I am in my seventh season of rearing Saturniid moths, but before July 2005, I only knew of the New England buck moth from books and conversation. It was pure chance that summer when I noticed a two-inch-long, reddish-brown, spiny caterpillar on my back step. Due to its size and a certain familiarity, I was sure it was a Saturniid. I was also sure that those multi-barbed spines were not friendly! (Be forewarned: if you come across any caterpillar, be careful. Some barbed spines can produce very painful stings.) But if I didn’t act quickly, the caterpillar would disappear under the house – an opportunity lost – so I grabbed a garden glove and scooped it up.
I quickly identified it as H. lucina. Although none of the Saturniids feed as adults, the hungry caterpillars certainly do. New England buck moths feed mainly on our native and abundant meadowsweet (Spirea latifolia) but will sometimes switch to trees such as wild cherry and oak in their final instars – the stages between molts, or skin sheddings, that caterpillars go through on the way to becoming moths. This one fed on the cherry leaves I offered it until, a week later, it made a shallow depression in a bed of moist peat and shed its final skin to reveal a hard, dark brown pupal casing.
In late September, a lovely, delicate female moth emerged. I named her Luci. Unlike most other Saturniids, these silk moths are day fliers, and the female “calls” for a mate in mid-afternoon. She does this by protruding a scent gland from her abdomen and sending her perfume into the breeze, where a male lucina will detect her pheromones with his large, feathery antennae, which is how moths “smell.” Luci was successful in pairing with a wild male that I directed into her cage. They coupled for about an hour, after which I had the extraordinary privilege of watching her lay eggs on a branch I had provided for her – a string of pale blue pearls.
It was like having my own window into a private world. First, she touched the tip of her abdomen to one side of the stem, then around to the other as if to measure its diameter. Then, with precision, she gently placed one egg next to another in rings around the stem, coating each one with a shellac-like substance to keep it from desiccating in our cold, dry, winter air. I have seen many other moths lay eggs, but this was by far the most exquisite.
In mid-May of this year, about 50 of Luci’s eggs hatched into spiny larvae. Similar to related gregarious species, such as the Io moth (Automeris io), they wait for their siblings to hatch and then form groups before moving off in search of food. The groups remain together until the third instar, after which time they begin to split up and wander away. I am now awaiting the emergence of Luci’s offspring as grown adults, sometime this September, from the thirty pupae I kept in order to continue rearing this species.
If you happen to be out in the woods or walking through a wet meadow this month, keep watch for this modest moth among the spirea, goldenrod, milkweed, boneset, and other plants in the wet meadow and edge habitat preferred by the New England buck moth. Because it flies by day, it’s one of the easiest silk moths to find. If your eyes are really sharp, you can look for the lacquered egg rings on the branches of its host plants as you’re snowshoeing this winter – and think of Luci in the sky… maybe not with diamonds, but certainly a gem.