Polyphemus / voltinism
Mothman617 at mediaone.net
Sun Aug 13 19:24:38 EDT 2000
I do live in a rural area just north of Boston and have had much experience
in rearing and collecting Saturniids. The Polyphemus are generally double
brooded here and are sporadic throughout the summer. Much depends on weather
conditions here in southern New England which can vary from year to year.
This year for instance the first brood of A. polyphemus appeared in early
June. The second brood of individuals appeared in mid- July to early August.
This second brood was very impressive in numbers. One night I counted up to
11 males at my blacklight. In 1997 for instance, the first brood appeared in
mid to late June and the second in mid August.
The Promethea moth (C. promethea) also is double brooded here in some years.
The latter appearing in early August. The Luna moth also may occasionally
produce a partial summer brood here, but only rarely.
"Martha V. Lutz & Charles T. Lutz" <lutzrun at AVALON.NET> wrote in message
> Chris wrote:
> "I've raised 30 polyphemus larvae this season on maple leaves from a
> obtained and hatched from last season. ( I don't know the food plant she
> reared on)
> It's mid August, the larvae just spun cocoons.
> I've read and heard repeatedly that in the Boston area that Polyphemus
> multiple broods. I can't imagine that if my brood should hatch within the
> two weeks into adults and mate that there would be enough time for thier
> progeny to mature in time for winter.
> They have been raised on fresh cut leaves provided daily and chose maple
> oak, alder, elm and birch. (all of which I provided in an effort to figure
> their prefered food plant)
> Q- What should I expect? How should I handle these cocoons?
> If they hatch and mate? will there be enough time before autumn to raise
> another brood? Does anyone know?"
> I'll try to respond to the various points one at a time.
> 1) Regarding larval food plant of the mother moth: originally known as
> the Hopkins Host Plant Selection Principle (from work done on beetles
> in the 1900s), the concept that what the female fed on as a larva
> influences her offspring's food preferences does not seem to hold true for
> Saturniids. That was the focus of some of my Saturniid work with H.
> cecropia a few years ago, and larval preference seemed completely
> unaffected by what the mother fed on; the biggest effect I found was
> hydration level of the leaves offered to the larvae.
> 2) It is possible that polyphemus moths have two summer broods in the
> Boston area, although it might depend on when the first brood hatches in
> the spring. When did your female hatch? I have some rearing notes on
> polyphemus, and could check them if you would like to know typical
> (non-manipulated) durations for larval life, non-diapause pupal phase, and
> time required for eggs to hatch. A female hatching in early May might
> produce offspring that would pupate in time for their offspring to be a
> second summer brood. A female hatching in late June . . . probably not,
> although some of her offspring might emerge after a month instead of going
> into diapause. Full sibs of Actias luna raised under the same conditions
> (in terms of food plant, daylength, and temperature) included both
> individuals that emerged after 3-4 weeks as pupae, and other individuals
> that overwintered and emerged the following spring (my own work from the
> past few years).
> 3) My polyphemus like maple (mostly Acer platanoides), but will also feed
> nicely on oak (several species). They will eat black cherry (Prunus
> serotina) but if some maple or oak is in the same cage, they will consume
> all of that before feeding much on the cherry.
> 4) If your larvae just pupated in mid August, then you can expect
> from all of them emerging to all of them entering diapause. It depends on
> the daylength cues they received. If they were reared outdoors, I would
> guess that some would diapause and others would emerge in mid to early
> September. If they were reared indoors, and you tend to provide a long
> 'daylength' with indoor lighting, then they may well all emerge in a month
> or so.
> 5) Rather than putting them in the refrigerator, try putting the cocoons
> in a VERMIN-PROOF (very important!!!) cage outside, in a place where they
> cannot be flooded by rain but will experience outdoor temperatures. An
> unheated garage works pretty well as a place to put the cage to keep it
> of the rain. Make sure the cage has provisions for emergence: something
> on the bottom to absorb the fluid they expel when they emerge, and
> something for the adults to climb onto and hang from while their wings
> expand. After 5 weeks, maybe 6 to be really safe, you can probably assume
> that any that have not emerged have entered diapause. At that point you
> can either refrigerate them OR leave them as is and they will emerge
> much in synchrony with the wild population in your area.
> 6) I have never, ever had full sibs of polyphemus moths mate. If anyone
> has had them do so, I would greatly appreciate hearing about it! Lunas
> will mate with sibs, and so will cecropias, but not polyphemus. Which is
> interesting, when you think about it!
> 7) "will there be enough time before autumn to raise
> another brood? Does anyone know?""
> So glad you asked! In the fall of 1996 someone sent me polyphemus eggs.
> reared them (indoors, with artificially long days) between mid September
> and mid November, and the moths emerged in early December. Being full
> sibs, these moths did not mate. Regarding the larvae, however: the
> fed happily on maple, continuing to feed even as the leaves turned color
> and began to fall. They preferred leaves fresh from the trees, rather
> leaves that had fallen. I was able to continue to find hydrated leaves
> well into the fall, but also made some 'seal-a-meal-for-bugs' packages. I
> froze fresh leaves and offered the thawed leaves to larvae. They
> individual servings, and would only feed on leaves that were still moist.
> Frozen leaves dry out rapidly, so this is a labor-intensive way to feed
> (thawing new servings more than once per day as the larvae get big), but
> some of these larvae did spin cocoons and emerge as adults--normal, albeit
> a bit smaller than their sibs raised on fresh (not frozen) leaves. The
> larvae fed on frozen leaves had a slightly slower growth rate; the larvae
> fed on senescing autumn leaves grew at a rate typical of summer brood
> polyphemus larvae.
> Let me know if you want any more information about this . . . I have about
> 12 years of data on playing around with Saturniids, their host plants, and
> various manipulations with the larvae. I have even had various Saturniids
> feed on Ginkgo and fern, although none ever made it through on those
> In Stride,
> Martha Rosett Lutz
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