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Post by kristinebl on Mar 18, 2021 4:54:35 GMT -8
Dear everybody, I hope for some advice. I'm not an entomologist, but life has turned out where I have started a scientific project with an aim to keep a Pieris brassicae in a laboratory stock culture. I have read a lot of articles about this thema, but practice things don't work out. The individuals were collected in the wild last year as caterpillars and now are emerging from their winter hibernation. The colony is held in 60x60x60 BugDorm cage, fed with 10% honey solution, at 26 degrees C, 16:8 L:D cycle under led lamps. For oviposition a Brassica oleracea is placed into the cage. For now several females and males have emerged, but there are no eggs. The humidity in the room is about 30%RH, could that affect it? Or is there an important detail I am missing?
Last september I tried the same with Pieris rapae. I collected 25 adult individuals in wild, reared the first generation in laboratory, but none of the second generation eggs hatched (I had about 60 F1 adult individuls, but the cage was smaller - 30x30x50cm - could it be, that there were no place for mating process and all 600 eggs were unfertilized? Or did the low humidity play a role - but in that case, the first generation hatched in the same conditions).
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Post by kevinkk on Mar 18, 2021 9:29:19 GMT -8
You might try Actias.de, perhaps someone there is more familiar with P. brassicae
You sound a lot like an entomologist...
Carolina Biological sells classroom kits for Pieris rapae, that might help you with that species.
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Post by catocala59 on Mar 18, 2021 10:06:45 GMT -8
If your food plant is well watered then the humidity inside the cage may be fine. Lighting is key to getting pairings indoors. A mixture of full spectrum and blue range LEDs will work, but the intensity is also important, and you may just need more light.
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Post by kristinebl on Mar 18, 2021 23:10:39 GMT -8
Thank you for the suggestions.
Well, I'm a biologist, but I never learn about insects, so right now everything is self-learned from scientific articles, but they always leave something out.
The light intensity in the midle of the cage is about 5000Lux (about 7000Lux in the upper part and 3000Lux near the floor). Right now I'm reading that perhaps a bilateral lighting should be tried that my light bulbs might be too concentrated and more scattered light would be better. But i had no chance to measure the spectrum jet, also the lamps I use are 3000K, so the warm light.
What made me worry is, that once I spray (distilled) water into the cage the butterflies start drinking it from all the surfaces. Also feeding was observed, should I move food sources into the cage? But even unfed individuals should lay eggs, so the pairing is the problem here jet.
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Post by bobw on Mar 19, 2021 1:38:05 GMT -8
In my experience Pieris need fresh flowers and don't feed well from sugar solution. Males generally need to feed for a day or two before successful pairing. It's many years since I tried to rear them but I always did them outside in natural sunlight, adults of most butterflies don't fare well indoors.
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Post by Paul K on Mar 19, 2021 5:47:54 GMT -8
How about salts? In nature males always look for salts before mate to enrich their sperm. Maybe that’s why they hesitate to copulate.
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Post by kristinebl on Mar 19, 2021 6:50:05 GMT -8
Salts? In what form and witch ones?
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Post by Paul K on Mar 19, 2021 7:00:44 GMT -8
Salts? In what form and witch ones? Hmmm...very simple, wet some sand with your urine. I’m not sure how that would work in the breeding cage as I have absolutely no experience about mating butterflies but it is working perfectly in the field. Hundreds of males come to it mud puddling. |
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Post by radusho on Mar 19, 2021 7:14:54 GMT -8
How about salts? In nature males always look for salts before mate to enrich their sperm. Maybe that’s why they hesitate to copulate. That is totally unnecessary. I did fine with just sygar and water with Hipparchias where females needs days for egg development before they start laying. It is all a game of a proper light and temperature nothing else. Keep it simple. Pieris are difficult to pair naturarly, you might have more luck with handpairing. |
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Post by nomihoudai on Mar 19, 2021 7:47:07 GMT -8
Salts? In what form and witch ones? Hmmm...very simple, wet some sand with your urine. Fun for the entire lab. Oh boy... As Radusho said it's for most species a question of temperature and light. Successful mating in captivity is not so simple. If it was, a lot of us wouldn't bother running around with a net. There is research labs, mostly plant ecology and plant insect interactions, that breed Pieris. I would try to locate one of these and email them. |
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