"What Happened to our Biggest Moths"

[Mike Quinn]

Hope everyone caught Peigler's article in the latest issue of the "News of
the Lep. Soc."

Peigler (2001) draws our attention to Boettner, et al. (2000) who squarely
lay the blame for the virtual disappearance of the Cecropia and Promethea
silk moths from New England on "an especially virulent parasitic fly named
Compsilura concinnata in the fly family Tachinidae." The parasitoid was
introduced as a biological control agent against the gypsy moth. According
to Milius (2000), "this fly has a known host range of almost 200 species,
and it would not be approved for introduction under U.S.D.A. guidelines and
standards today." Michael Collins is cited as pointing out that "one reason
this insect is so successful biologically is that is escapes hyperparasitism
by killing its hosts quickly." Peigler says he "found published records of
it parasitizing many nontarget hosts in North America, including species in
the Papilionidae, Nymphalidae, Hesperiidae, Sphingidae," and the following
additional silk moths: Luna, Io, and Polyphemus. Peigler notes that this
parasitoid is now found in California as well...

Peigler, R. S. 2001. "We now know what happened to our biggest Moths." News
of the Lep. Soc. 43(1): 30-31.

Boettner, G. H., J. s. Elkinton & C. J. Boettner. 2000. Effects of a
biological control introduction on three nontarget native species of
saturniid moths. Conservation Biology 14(6): 1798-1806.

Milius, S. 2000. Fly may be depleting U.S. giant silk moths. Science 158:
359.

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This best paper to get a copy of is Boettner's.

According to Boettner, et al. (2000), *Compsilura concinnata* was repeatedly
introduced into North America from 1906 until 1986, "and has been recorded
killing over 180 different species of native Lepidoptera, Coleoptera, and
Symphyta in North America." 

The authors monitored 500 Cecropia larvae in Massachusetts and found that
none survived beyond the fifth instar.

They simultaneously deployed cohorts (n=100 per cohort) of the first three
instars of Cecropia larvae. C. concinnata was responsible for 81% of
Cecropia mortality.