rearing of chalcedon checkerspots

[Niklas Wahlberg]

Hi!
   I've been rearing the European versions of the Euphydryas checkerspots
(ie Hypodryas maturna and Eurodryas aurinia) for the past few years as a
part of my PhD project. Since they have a rather similar life cycle, I
think I can help. The best way to know if the eggs are fertilized is their
colour. Fertilized Euphydryas (sensu lato) eggs tend to change colour from
yellow to purplish a few days after being laid. I have found that the eggs
hatch after about 10 days when kept at room temp (about 22 C, whatever that
is in Farenheit). If they are kept outside in a shady place hatching will
take longer.
   Euphydryas butterflies are indeed obligate larval diapausers. In Finland
I have kept diapausing larvae outside during winter in an unheated shed.
The most important thing is keeping the humidity right. If it is too dry,
the larvae die, and if it is too wet they tend to mould. In San Jose I
would presume that the larvae diapause during the driest part of the year.
The young larvae will enter diapause when they are ready, whether you want
them to or not! Once they are in diapause, put them in a cool place (eg a
basement or something similar) until their host plant begins to grow again
in nature. It is best to check on them occassionally to make sure they are
not drying out.
   I hope this helps.

Cheers,
Niklas



_________________________________________________________________________

   Niklas Wahlberg                          
   Department of Ecology and Systematics    
   Division of Population Biology           
   PO Box 17 (Arkadiankatu 7)               
   00014 University of Helsinki
   Finland                                                         
   p. +358-9-191 7378, fax +358-9-191 7492  
 Check out our www-site:                    
  http://www.helsinki.fi/science/metapop/