LATE Blue Grass and early skippers--another insight.

[Michael Gochfeld]

With regard to how Cobweb and Dusted Skippers get to use Bluestem grass
which doesn't green up until mid-summer (at least in NJ), Norbert
suggested a uique strategy: 

The larva-in-egg option is one I hadn't thought about. It's sort of an
analogue to ovoviviparity in some vertebrates where the eggs hatch in
the female body and live young emerge.

Ironically, we cited a reference in Butterflies of New Jersey by
Heitzman and Heitzman (1969--a life history of Hesperia metea)) who
reported that the half-developed larvae of Cobweb Skipper bury deeply
into the base of a Bluegrass clump, where they estivate.  They hibernate
in the center of the grass plant in a sealed silk, chamber.  In spring
the larvae emerge and pupate immediately. That doesn't get us out of the
blind that the half-developed larvae are doing their first half of
development early.  So we need to establish when the egg hatches and
whether it pulls a "Dione Copper ploy" as Norbert describes below. 

Norbert Kondla wrote:
> 
> Re. below, fascinating. One possible explanation is as follows: in a
> case where the adults fly in the spring and there is no green foliage of
> the suspected host grass to sustain the larvae the same spring, then the
> larvae cannot be using said suspected host prior to the presence of
> green foliage. What they could be doing is using the green foliage later
> in the season when it is available and then overwintering in a larval or
> pupal stage until adult emergence the following spring. Or they could be
> eating other grasses prior to the bluestem greenup. An interesting
> snippet that I learned within the past year is that some butterflies
> that overwinter as an egg really do not overwinter as an egg at all. The
> case of Lycaena dione Dione Copper as reported to me by Sue Borkin from
> her research. The 'egg' actually turns into a larva within the egg
> casing prior to winter; so the overwintering 'egg' is no longer an 'egg'
> even though it looks that way from the outside. Who would have thunk it
> :-) This makes me wonder how many other butterflies that are reported to
> winter as eggs actually winter as larvae within the egg casing --- so
> getting back to the skippers mentioned below the eggs laid by the adults
> in the spring could remain as eggs until the host grass is greening up
> or they could develop into larvae within the egg casing, waiting for the
> right environmental cue to emerge and start chomping on the fresh
> greenery
> 
> -----Original Message-----
> From: Michael Gochfeld [mailto:gochfeld at EOHSI.RUTGERS.EDU]
> Sent: Wednesday, August 06, 2003 4:59 AM
> To: leps-l at lists.yale.edu; WCanButterflies at yahoogroups.com; Lepstalk
> Subject: [leps-talk] LATE Blue Grass and early skippers
> 
> The convergence of two events leads me to pose a puzzling question that
> I'm
> sure some list members can answer.
> 
> I have been studying grasses, and on a recent (mid-July) field trip,
> noted
> that the green tips of new growth of bluestems (Andropogon virginicus
> and
> Schizachyium scoparium (excuse spelling) were just beginning to show
> amid the
> clumps of last years vegetation (central New Jersey).
> 
> Last night at our local NABA meeting, Sharon Wander gave a
> well-illustrated
> talk on larval hosts of NJ butterflies.  She highlighted several
> possibly
> obligate bluestem feeders among which are two of our earliest skippers
> (Cobweb flying mainly in April and Dusted flying mainly in May).
> 
> So how do these early fliers do it.  It's easy enough to locate
> bluestems,
> one or more species are widespread.  But when these species are flying
> (up
> until mid-June at the latest) the only apparent clue is the dead
> foliage.
> 
> If the larvae hatch quickly they won't have any green growth to sustain
> them.  I couldn't find a statement on how long it takes the eggs of
> these
> species to hatch---they'd have to be dormant for weeks, or the first
> instar
> would have to take a prolonged nap before it found something to eat.
> 
> Or could they be eating something else at the earliest stages.  MIKE
> GOCHFELD
> 
> ------------------------ Yahoo! Groups Sponsor ---------------------~-->
> Buy Ink Cartridges or Refill Kits for Your HP, Epson, Canon or Lexmark
> Printer at Myinks.com. Free s/h on orders $50 or more to the US & Canada. http://www.c1tracking.com/l.asp?cid=5511
> http://us.click.yahoo.com/l.m7sD/LIdGAA/qnsNAA/CCYolB/TM
> ---------------------------------------------------------------------~->
> 
> TILS Motto: "We can not protect that which we do not know" © 1999
> 
> Subscribe:  TILS-leps-talk-subscribe at yahoogroups.com
> Post message: TILS-leps-talk at yahoogroups.com
> Archives: http://groups.yahoo.com/group/TILS-leps-talk/messages
> Unsubscribe:  TILS-leps-talk-unsubscribe at yahoogroups.com
> For more information: http://www.tils-ttr.org
> 
> 
> 
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

 
 ------------------------------------------------------------ 

   For subscription and related information about LEPS-L visit:

   http://www.peabody.yale.edu/other/lepsl