Smerinthus ophthalmica Pairing and Eggs

We have finally obtained a Smerinthus ophthalmica pairing and eggs!

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At last, we finally did it! This morning when we checked our pairing cage, our captive raised Smerinthus ophthalmica female had paired with a wild male! When the female has first unexpectedly eclosed two days ago, we were almost certain we were about to loose this stock because it was probably a few weeks too early for the wild population to be in flight, and even if it was, the horrible weather this week would ruin any chance of pairings. Well, this fine looking determined male proved us wrong as it somehow found its way to our doorsteps. His appearance also confirms that the local flight has already begun.

​We tried to get some good shots of the pairing while they were still hooked, but unfortunately, when we tried to move them onto a nice willow background, the female became irritated and separated from the male which also happened the last time we had a pairing when we tried to get a good shot. The separation at this point is completely harmless though, since the actual copulation had already finished long ago in the middle of the night, but we did loose a good shot!

Below we have the wild male, a very large grey form who looks freshly eclosed. The male's forewing length is 4.2 cm, the same as the female's, but it has a slightly larger thorax and head so perhaps in that sense you could say it's larger than the female.  The males and females of this species are not very dimorphic -  there are only a few subtle differences if examined closely. Mainly, the antennae are larger and pectinated, and the abdomen is much slimmer and curved upwards like a tail. Also, the wings are just slightly narrower and at rest, he angles them upwards posteriorly. Also, since Smerinthus ophthalmica adults are highly variable in color, it's hard to find two that look exactly alike. This male is much greyer (more melanic) than the female and the brown is much darker. In fact, when compared to the female, the female actually looks somewhat intermediate between a grey and brown form.

Okay - so back to the female. Immediately after splitting from the male, the female began to become frantic, flying around recklessly all over the room so we were forced to put it back in the container. However, about an hour later, we took it out again and placed it on some willow cuttings to take a photo with the male, but it became frantic again, but this time it began circling around the willow cutting and laying eggs on them! The way this moth oviposits seems very effortless; it hardly land or curls its abdomen - maybe for a split second - and out slips a flat shiny pale yellow egg.  

It ended up laying 2-3 dozen on the leaves, mostly singly, but sometimes is larger clusters. When it got tired and uncooperative, we put it back in the container with willow cuttings and paper towels, and throughout the day it laid several more in there too, both on the cuttings and the paper towels. We didn't get an exact count (we will when she lays all her eggs), but it looked like at least 70-80 in there already. That means we already have about a hundred eggs on the first day, though the last female we had (the mother of the current one) only managed to lay this much before running out. So, the current female has probably laid over half of its eggs and will probably finish up in a day or two, 

Finally, here are the shiny little eggs below. They are extremely smooth and are white the moment they are laid but quickly turn to a pale yellow after drying,  ​There is a little bit of clear "glue" on the base sticking them to the substrate. 

Overall, obtaining this pairing and eggs is extremely exciting for us since it was an incredibly rocky road to get here. The origin of this now thriving stock began with a single egg that we stumbled across by pure chance last June (we were actually looking for Papilio rutulus eggs then). At the time we didn't even know what species' egg we had found, but we kept it anyway and reared it out. It eclosed in late August and was very fortunately a female which allowed us a chance of pairing, but by the time a male came, the female had already deposited about a hundred infertile eggs. It laid just a single fertile egg after the pairing before dying. That single fertile egg was then reared into the fall and went into diapause, eclosing now as the current female (very lucky again to be female). The rest of the story is told above. Thus, finally having a successful pairing and oviposition is extremely fortunate and has been very long waited. We now have a nice batch of eggs ready to hatch in 7-10 days, meaning we'll have plenty of voracious green caterpillars in no time!

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Authors
Alan Liang

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