I left my recently emerged Polythysana cinerascens female outside in a wicker basket in order to attract wild males. After some hours, I came out to see her and for some reason her abdomen was torn apart, with some ova coming out of it (picture attached).
However, she seems to be relatively fine and still calling. What are the chances (if any) that eggs that are still inside of her can be fertilized?
I would really appreciate your help. Thanks in advance.
Fernando, She will probably still be able to scent and attract wild males. They will probably be able to pair with her. However, she may have great difficulty deposting eggs, as abdominal contractions may force the eggs out the tear rather than through the proper opening, or abdominal muscles may be so damaged that eggs cannot be expelled. Males usually fly in during hours between 10:00 am and noon. If you can protect her within a screened enclosure, capture the males and insert them into the same enclosure, you may have better success. Once a predator "knows" there is food in the area, or a playtoy (maybe done by a cat), the predator will probably return.
Did any of the suspected dead pupae rehydrate after you wet them? or did all of those pupae perish?
I have heard that fertilizing by hand has worked from time to time, but I'm not sure how the process works or how well it has worked. I believe the males are killed and the seminal vesicles are removed and then manipulated, somehow. The person who has been doing it didn't tell me very much. Jeff Prill
Hi Fernando, Many people do not realize that the eggs are not fertilized at the time of the pairing. The eggs are fertilized as they are deposited as they pass through the natural opening of the female. It is at this time that the eggs are bathed in a mixture of the male's sperm and the females "glue". If the female is not able to expel the eggs naturally, then they will not be fertile, and you will have to resort to method Jeff has mentioned. I have never tried it and would not be able to describe method, but that would be your only choice, or hope aanother female emerges. Did you have any luck with rehdration of the pupae that appeared dead? I suspect a lizard, a mouse or a vole got into the basket through the narrow openings between the "wicker" bands. I would not leave them in the basket if you hope to get a pairing, or for that matter have any moths. Bill Oehlke
@bill: that's very good info, I didn't know that eggs were fertilized in the moment they were deposited.
As for your other question, I'm very sorry, I forgot to respond to it in my previous post; I tried rehydrating the pupae, but I don't know if I succeeded. There's one pupa that dried completely (lost weight and volume). The rest of the pupa lost volume, but not weight, so I don't know what to think. Anyway, there's still other 3 healthy-looking female pupae, so if this one isn't able to deposite fertile eggs, there's still a chance.
As for the pairing, don't worry, I already moved the moths from the wicker basket to an enclosure ("caterpillar castle"). I was using the wicker basket because the female didn't succeed attracting males when she was in the enclosure (I thought maybe the fine mesh didn't allow a good airflow).
Fernando, You can try to gently squeeze the eggs through the natural opening, even if it means putting tape over the wound. It is a long shot, but it might work for you to at least get some fertile eggs. Sometimes males can mate more than once and provide enough sperm to fertilize two or three females, but I would advise that you try to get fresher males to fly in to other females (hopefully you will have some). In other words, I would not release the male that has already paired, but save him alive in cool conditions just in case no more males arrive when you have your next female out. Then you can let him pair, and hopefully his sperm will still be good. Good way to keep him still and from expending energy is to put him in a plastic tub, lid on tight, no air holes, and put the tub in the refrigerator crisper, above freezing, not in the freezer.
I do not think so. I think it is only important that the eggs get washed in the male sperm as they exit the female's body. There is probably, under normal conditions, a pressure bath as the eggs are expelled. You might or might not be able to duplicate it manually. I suspect sperm was probably stored in some sort of receptacle in the female's body. Just guessing, but i suspect the pressure exerted by the eggs probably squeezes some of the male fluids into the track and coats the egg as it gets expelled. The tear in the female's body may have caused her to lose much of the fluid around the eggs by evaporation so she may be entirely bound. Maybe it wil work, maybe not. All you have to lose is some time.