Science Buddies: "Ask an Expert"

Hello,

I would like to do the project "Does Temperature Affect the Rate of Butterfly Development" with the Cinnabar Moth. These moths are all over Tansy Ragwort right now and were introduced as a biological control to wipe out these plants. I know these moths cocoon over the winter since I took care of one last year. I would like to do the temperature project with these moths, but I need to speed up the cocooning time to meet my project deadline (March 2014). I've read about other scientists speeding up cocooning periods by putting the cocoons in the refrigerator. Can you give me any specifics about this? How long do the cocoons need to be refrigerated and at what temperature?

Thank you,
BugBen

Hi Bugben,

There is remarkably little on Google and PubMed about cocooning. I looked up the cinnabar moth and it is certainly a pretty insect, but as you must have seen, there’s nothing about how to modify the cocooning process.

You said that they form cocoons and overwinter, the moths emerging in the spring I assume. Insects that overwinter go into a diapause state where their oxygen consumption and metabolic rate go way down so they can survive freezing. I don’t think the cinnabar moth has to go through a cold period in order for the pupa to metamorphose.

I would think that you could prevent diapause by keeping the temperature above freezing and providing extra hours of daylight, although I couldn’t say how much. The larvae should grow into adult moths without having to go through the winter quiescence, so you should get adult moths sooner.

Sorry I can’t give you any more information. I think you’ll just have to gather some cocoons before the pupae go into diapause and try various combinations of light and temperature to see how it effects the time of emergence.

Best wishes,

Sybee