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Index of Subjects --089e0112cf10db090b04e4a7d735 Content-Type: text/plain; charset=ISO-8859-1 Thanks for taking the time, Steve. Yes, a bit of a vague question, but intentionally so. I am working on an article that involves comparing peaks in abundance of different temperate zone diptera and lepidoptera (caterpillars) with timing of bird breeding stages. Some literature suggests that, in general, there might be distinct peaks in caterpillar abundance for forest-associated lepidoptera species having deciduous vs coniferous host plants. And I am wondering whether there are life history or ecological factors that would also lead to this somewhat bimodal distribution of peak abundance ( if in fact it is a documented phenomenon in North America). Thanks for the ideas and I will definitely check the site you mention. Cheers, James On Friday, August 23, 2013, Steve Shaw wrote: > No idea, but it sounds like a bit of an odd question. Are you trying to > tie it to bird abundance or migratory period, the timing of which might be > more rigidly (and unfavorably) fixed for bird migration than for insect > emergence if the climate warms up, as I recall some have speculated? > > As herbivors, you'd expect caterpillars to be dependent upon when their > special food plant(s) starts to sprout, which is presumably variable for > different species plus weather-dependent. For arboreal caterpillars, there > are no (or few) leaves on deciduous trees around here (Halifax) until about > the third week in May, but in Washington DC (etc) when we lived there, > much further south, things started to warm up in March; same or earlier in > Vancouver. As well, certain species have more than one generation per > year. > > A way to check at least for butterflies in NS would be via the on-line > nicely revamped Butterflies of NS site, which besides images gives the > empirical flight period data actually observed for each species, but also > the inferred egg-laying and larval timing. Though apparently not usually > measured directly, the latter may be quite accurate because the flight > period of the adult is usually quite short, so the eggs obviously have to > be laid before the end of that. You'd have to go through it species by > species and compile an average histogram by week, if that's what you're > after. > Don't know how you'd do it for the much larger number of moths, but Jim > Edsall or others might have some sources. > Steve (Halifax) > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > On 23-Aug-13, at 3:42 PM, James Churchill wrote: > > or roughly June and August for Canada? > cheers, > James. > > On Fri, Aug 23, 2013 at 3:25 PM, James Churchill < > jameslchurchill@gmail.com> wrote: > >> hi folks, >> >> Can anyone provide information on the temporal distribution of >> caterpillar abundance in NS or North America? >> >> Do we by chance have two peak periods of caterpillar abundance >> corresponding roughly to May and September? >> >> cheers, >> James. >> > > -- > James Churchill > Kentville, Nova Scotia > jameslchurchill@gmail.com > (902) 681-2374 > > > -- James Churchill Kentville, Nova Scotia jameslchurchill@gmail.com (902) 681-2374 --089e0112cf10db090b04e4a7d735 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Thanks for taking the time, Steve. Yes, a bit of a vague question, but inte= ntionally so. I =A0am=A0working on an article=A0that involves comparing pea= ks in=A0abundance of different temperate zone diptera and lepidoptera (cate= rpillars)=A0with timing of bird breeding stages.=A0<div> <br></div><div>Some literature suggests that, in general, there might be di= stinct=A0peaks in caterpillar=A0<span></span>abundance=A0for forest-associa= ted=A0lepidoptera species having=A0deciduous vs coniferous host plants. And= I am wondering whether there are life history or ecological=A0factors that= would also lead to this somewhat bimodal distribution of peak abundance ( = if in fact it is a documented phenomenon in North America).=A0<span></span>= </div> <div><br></div><div>Thanks for the ideas and I=A0will definitely check the = site you mention.</div><div><br></div><div>Cheers,=A0</div><div>James</div>= <div><br></div><div>On Friday, August 23, 2013, Steve Shaw wrote:<br><bloc= kquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #cc= c solid;padding-left:1ex"> <div style=3D"word-wrap:break-word">No idea, but it sounds like a bit of an= odd question. =A0Are you trying to tie it to bird abundance or migratory p= eriod, the timing of which might be more rigidly (and unfavorably) fixed fo= r bird migration than for insect emergence if the climate warms up, as I re= call some have speculated? =A0=A0<div> <br></div><div>As herbivors, you'd expect caterpillars to be dependent = upon when their special food plant(s) starts to sprout, which is presumably= variable for different species plus weather-dependent. =A0For arboreal cat= erpillars, there are no (or few) leaves on deciduous trees around here (Hal= ifax) until about the third week in May, but in Washington DC (etc)=A0when = we lived there, much=A0further south, things started to warm up in March; s= ame or earlier in Vancouver. =A0As well, certain species have more than one= generation per year.=A0<div> <br></div><div>A way to check at least for butterflies in NS would be via t= he on-line nicely revamped Butterflies of NS site, which besides images giv= es the empirical flight period data actually observed for each species, but= also the inferred egg-laying and larval timing. =A0 Though apparently not = usually measured directly, the latter may be quite accurate because the fli= ght period of the adult is usually quite short, so the eggs obviously have = to be laid before the end of that. =A0 You'd have to go through it spec= ies by species and compile an average histogram by week, if that's what= you're after. =A0=A0</div> <div>Don't know how you'd do it for the much larger number of moths= , but Jim Edsall or others might have some sources.</div><div>Steve (Halifa= x)</div><div>=A0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</div><div><br></div> <div><div><div>On 23-Aug-13, at 3:42 PM, James Churchill wrote:</div><br><b= lockquote type=3D"cite"><div dir=3D"ltr">or roughly June and August for Can= ada?<div>cheers,=A0<