refrigeration of adult lepidoptera and lifespan

[kevinkk]

Does anyone have an opinion about refrigerating an adult moth in order to increase it's lifespan and have a greater chance to mate?

The issue I am wondering is can this effect fertilility. One of last year's buyers told me they were refrigerating adults while waiting for another of the opposite sex.
Now I recieve email mentioning low fertility, it's a concern, because now I either end up with possibly some 500 caterpillars I can never take care of,
or lose money dolling refunds later.

I can see where this might work, but I think temperature would be a factor.
Before you ask, the parents were wild caught in June of 2024 and I raised the larva.

[eurytides]

I don’t have numbers on fertility but I have done this with silkmoths and they can live a month or more in the fridge. Their metabolism isn’t zero, so over time they do get weaker and use their fat stores.

[Chuck]

The temperature and duration tolerated, and with what effect, depends on the moth species. Attacus atlas does not like to be refrigerated AMHIK. I suspect that the more northern Saturnids would be more tolerant, and the Canadian May/ June species, which may endure frost anyway. <- bad grammar but you know what I mean.

Our fridge is set for 37F, which I wouldn't stick many species in for very long. Make it 47F and I'd think a lot of species would tolerate it, and for longer.

[bobw]

I've used this method many times in the past and didn't notice reduced fertility, but I rarely kept them in the fridge for more than a few days. My fridge is always set at 4 degrees C. The insects are not fully dormant and do become weaker over time, I guess it's not too dissimilar to a cold day in natural conditions. One thing I have noticed is that when they're taken out they're desperate for a drink, I've found it helps if I take them out once a day, give them a feed and let them warm up for an hour before putting them back in the fridge.

[adamcotton]

I think it would be important to put Saturniidae inside a sealed container otherwise they would desiccate while in the fridge. Obviously they cannot replace any lost body water after removal from the fridge.

Adam.

[kevinkk]

Thank you all, those are all factors, some of which I hadn't thought of.

We all have different temperatures for the fridge, the humidity factor is interesting, even using wet sponges in the veggie crisper, I cannot raise
the humidty to any significant amount, maybe that's how the appliance works, I don't know.

In any event- it seems I am still in a spot. Low fertility. Ok, that could be anything. I've had virtually every anomaly occur raising lepidoptera, it's a calculated risk and that's about it. As a seller, you either need to keep shipping cost down, so refunds aren't a big loss, or simply accept that it is a risk.

By the by- the Nymphalis antiopa I raised last year and tried to hibernate, it didn't work, I only fed them once before storing them, clearly a mistake,I wish I'd simply let them go at this point. I kept them in the fridge, maybe the freezer would have worked.

[Chuck]

I’d vote no on the freezer. While true that last winter the outdoor temp was lower than the freezer, and antiopa comes out on sunny days in March, what’s the loss rate in nature? It’s probably high.

Plus there are localized temperature tolerance in all animals. Inuits play ball when I would literally be dying. Floridians wear coats while tourists are in the pool.

Low fertility has many causes, temperature would be a least concern.

[eurytides]

Yes, I forgot to mention humidity is a factor and fridges dry things out. I store bugs in almost airtight containers and ziploc bag them. They won’t asphyxiate.