First Antheraea polyphemus Hand-pairing

We have finally obtained a successful hand-pairing of polyphemus moths (Antheraea polyphemus)!

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Before we jump into the exciting news of the day, lets just go over all of our failed pairing attempts over the past week. Ever since we had been getting nice eclosions of male and female polyphemus lately, we struggled to obtain even a single pairing. The species is known to be very difficult to obtain natural pairings in captivity and thus most breeders will put the female in a cage to call wild males, which is usually successful as the moth is the most widespread Saturniid in north America and is one of the commonest in its range. We are supposed to have a population here in Albany, California as there have been sitings not too far from here, though we have never seen one around here ourselves. Still, we assumed calling a male in would be possible as long as there are a few out there, but its been many days trying with different females in the cage and nothing has come. Either the moths are not actually here, or its too early for them, though it is already May and the moths should be bivoltine here, emerging as early as March and April in nearby counties. 

Along with trying to call in wild males, we also put sets of males and females in a very large flight cage outside in order to give airflow which should help with natural pairings. Some have had success this way, though it is usually luck-based, and we didn't have much luck. The moths just sat there every night hardly moving at all - the females called patiently for the males which would just rest on the other side of the cage motionless, completely ignoring of the pheremones in the air.

Since we had little confidence left obtaining a pairing naturally through calling a wild male or in a flight cage, we tried hand-pairing the moths every other night. However, the males had very flabby abdomens and wouldn't cooperate no matter what we did. We even busted a few through using too much brute force to mash the moths' genitalia together. We were simply doing something wrong.

Well, today we tried again with hand-pairing close to midnight while the female was calling and the males were awake. It was a very warm night, which made them more active then usual. We took the female we found and the larger male that eclosed two days ago and went at it, but failed again as always. Then, we tried the female that eclosed today with the smaller male that eclosed two days ago with the firmer abdomen, and after testing around with different angles for a few minutes, they paired instantly! There must have been something wrong with the angle we were hand-pairing them before, as this time at about a 120 degree angle, the male calmly moved its abdomen and found its way to the females' genitalia with no assistance whatsoever besides holding them in position. It seems practice and trial and error is needed in order to get the knack for hand-pairing these moths. Every species is slightly different, and thus our long experience pairing Papilios wasn't quite enough to get us a polyphemus pairing immediately, but luckily we managed to figure it out. 

After obtaining the pairing, we gently placed the two in a container in the dark. They actually split by accident a few minutes after the first pairing, but we quickly held them together again and they paired up again. Hopefully, they will stay put until tomorrow and the male will successfully ejaculate (the problem with hand-pairings sometimes is that if the male isn't in the right position, it will simply hold onto to the female a long time but not actually ejaculate). Then we're probably guaranteed to get 200 plus fertile eggs this week, and if we get more hand-pairings that'll be at least 200 more for each.

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Authors
Alan Liang

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