ovoviviparity

[Doug]

Dr. Miller - can you add to the answer to the question below?  Leps-L is a
discussion group for Lepidoptera.  This question forwarded by Gordon Ramel, was
asked by Estela Favrat from the Agricultural Microbiology/Zoology institute in
Argentina:

>>I need to know the name of a Lepidoptera example that has ovoviviparity
>>reproduction. As I am in a hurry I beg you to answer me soon.

I have always understood that butterflies (and assumed moths, without much basis)
were all very similar in the design of their egg production.  They are basically
assembly lines in which eggs are manufactured in a continuous process, continually
moving as they mature, closer to the ovipositor.  Due to the sheer quantities of
eggs many butterflies produce, due to space limitations, I imagine it would be
generally impracticle to slow the production line. Fertilization logically would
occur as soon as the egg is mature and able to be deposited on a hostplant.  Most
authors cite other methods of insuring successful quantities of offspring, rather
than ovoviviparity (retention of fertilized eggs until briefly before hatching,
usually to minimize predation):
1.- Large quantities laid
2.- Hiding eggs in bark or other crevices
3.- Laying eggs with symbiotic protective insects (usually ants)
4.- Producing and coating with special "hard shell" enzymes
5.- Selection of difficult to find sites on hostplants and choice of hostplant
location
6.- Ovipositing aggregates (protections in number as in 1.)
7.- Opositing single eggs far apart (to take advantage of 5.)
8.- Camoflauging eggs (color/texture same as hostplant)

Since typically the many egg strategy is pursued for propogation, I would guess
that the eggs with shortest cycle time are of those species with the "best"
nutrition, which undoubtable could reduce developmental time, all else equal.  One
candidate for shortest cycle time might be Feniseca tarquinius, a species that
occurs in North America and is commonly known as the "Harvester" because it eats
aphids (as a caterpillar).  I believe the larva emerge from the deposited eggs in
three days.  However, I don't know (but doubt) that the eggs are retained very
long after fertilization.  If there is another candidate group of Leps for
ovoviviparity, it would be those who produce the fewest eggs, perhaps the
"assembly line production" is slowed sufficiently due to low throughput so that
after fertilization enough resident time is allowed before ovipositing to allow
near development of the embryo.  I would not guess that retention of eggs within
the female is a viable option for most butterflies, as the lifespan of the adult
is frequently as long as the time required for the larva to emerge from the eggs,
thus too few eggs would be produced.  That brings up another option - longer
living butterflies are probably better candidates.  Maybe someone else can provide
further information here.

Estimada Estela, Te deseo mucha suerte en tu investigacion, posiblemente el
profesor  Dr. Thomas Miller, profesor de la fisologia de insectos, en UC Riverside
chmeliar at ucrac1.ucr.edu puede darte una respuesta mas especifica.  Si cualquier
cosa requiere aclaracion, no dudes en hacerme saberlo y te contestare de acuerdo a
mis conocimientos.  Saludos.
________________________
Douglas David Dawn
N.  25º 37.408'
W. 100º 22.003'
Altitude 910 meters
Sylvania Pinus-Quercus


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