Rearing notes for our one-eyed sphinxes (Smerinthus cerisyi) originated from Colorado.

Rearing Notes 3/30/17-4/6/17:

See Smerinthus cerisyi Pupa Near Eclosion

One of our Cerisyi's sphinx (Smerinthus cerisyi) pupae has eclosed into a male. These originated from Colorado.

The male Smerinthus cerisyi eclosed this morning and is in perfect shape. Now all we have to wait for is the female to eclose tomorrow or the day after and we'll have a pairing. Below are pictures of the male cerisyi, which greatly resembles S. ophthalmica, though differences are apparent.

The differences between the male Smerinthus cerisyi and our west coast S. ophthalmica suddenly became quite obvious now that we have seen both with our own eyes. The sources and photos we have looked at are correct - the cerisyi's wings are more jagged along the lateral edges and the veins are paler and thus much more contrasting. This makes the ophthalmicas appear much more "smooth" in comparison. Also, this male cerisyi's antennae are proportionately large relative to the body. The abdomen tip where the genitalia is located doesn't look quite the same shape either. And, the most apparent difference (though hard to tell from the photo), is the large size difference between the wings and abdomen of cerisyi and ophthalmica. Their thoraxes and heads are actually about the same size, but this cerisyi's abdomen is smaller, and the wings are significantly shorter, with a forewing length of just 3.1 cm compared to our ophthalmica's 4.2 cm. The cerisyi's eyespots also seems to have more black around them and the pink is darker. 

As far as behavioral differences, the cerisyi seems to be a much more quicker and urgent flyer, flying about all over our room the second it got dark unlike our ophthalmicas which were much more heavy weight and beat their wings more slowly. The cerisyi also reveals its eyespots when prodded on the head just like the ophtahlmicas, but in addition to the eyespot revealing, the moth also shakes its body up and down (not the vibration right before it takes flight), and holds the wings up at an angle. 

​Below is a comparison between S. cerisyi and S. ophthalmica.
​Row 1: S. cerisyi male; Row 2: S. ophthalmica male; Row 3: S. ophthalmica female.

One of our one-eyed sphinx (Smerinthus cerisyi) pupa is near eclosion.

A few weeks ago we received four Smerinthus cerisyi pupa, three male and one female. One of the males got moldy and died within the first few days which we suspect may have already been dead upon arrival as it was a dark and slightly dried up looking. However, the other three have remained nice and healthy and today the larger of the two males began to show wing patterns, meaning it is close to eclosion. Unlike our S. ophthalmica pupae which have a much darker, almost jet black cuticle which makes it impossible to see wing pattern development, these ceriyis are a much lighter reddish brown, making the black wavy like pattern clearly visible on the wings. The abdomen of the pupa also feels much looser as the segments move around much more easily when gently pulled from side to side. The moth will probably come out within the next few days and we'll be waiting on the female pupa. 

We have received four Smerinthus cerisyi (one-eyed sphinx) pupae originated from Colorado.

 We currently have a single locally obtained and reared female Smerinthus ophthalmica pupa that is in diapause. Since we are uncertain if we are going to be able to obtain a pairing with just one female, especially when we don't know when the local population flies and when this pupa will eclose, we decided to get four Smerinthus cerisyi pupae just in case. Our thinking was that since S. cerisyi and ophthalmica are very close related, a female cerisyi should be able to call in a wild ophthalmica. 

We had expected the cerisyi pupae to look nearly identical to ophthalmica's, but when the pupae arrived we were in for quite a surprise. We cannot say for certain that the cerisyi and ophthalmica pupa that we have are each representative of the typical phenotype for their respective species, but we observed quite a few differences. First off, the cerisyi pupae are far smaller than we had imagined - the three males weigh 1.6, 1.4, and 1.1 g respectively while the female weighs 1.7 g, half the size of our female ophthalmica pupae which currently weighs 2.9 g (originally 3.1 g several months ago). This is such an incredible size difference that it is unlikely due to variation from rearing conditions but almost certainly genetic. In addition, three of the cerisyi pupae are distinctly glossy reddish brown in color rather than a slightly duller jet black like the ophthalmica, though the fourth cerisyi is on the darker side which we suspect is due it being close to eclosion. Further, the cerisyi seem to have pointier and larger cremasters in relation to body size and have narrower abdomens while the ophthalmica's is slightly blunter like Pachysphinx modesta's. 

We weren't expecting such differences between the two species and are now uncertain about the compatibility of the two in reproduction. Several authors still consider the two to be subspecies of each other rather than separate species, which by definition would mean they should readily produce offspring with near 100% fertility. However, looking at the huge size differences and slight pehnotypical differences between the two species, we are becoming somewhat doubtful about the viability of the eggs. However, if we do manage to hybridize these two species (or subspecies), then it will be extremely interesting to see whether or not the observed differences we have made are attributed to genetics or not. Ideally, it would be even better if we could produce a pure strain of both the Coloradan cerisyi and Californian Ophthalmica and treat them as control groups.

Another burning question of ours that an experiment like this would solve would be whether the four larval instars observed in Ophthalmica is truly genetic or simply a result of extremely ideal rearing conditions (doubtful, but that's what some have said). We assume that the Coloradan cerisyi had five larval instars as this seems to be the norm based on literature. Thus, if a S. cerisyi x ophthalmica cross produced offspring with significantly different proportions of larva that undergo four or five instars than the two pure strains, then we could conclude that the four instars in Ophthalmica truly is genetic and may be a defining trait of this species, or at least of the local population of this species.

And, one more thing - we are very curious to know the egg size of these Coloradan cerisyi because our local Ophthalmica females seem to lay disproportionately large ones for the size of the species, but each female lays very few (~100). This gives rise to larva with large birth sizes which becomes undermined by the fact that they only undergo fourth larval instars - in essence, a less extreme R-selected reproductive  strategy that favors fewer but larger (assumed fitter) offspring. This actually seems to be a pattern among Saturniids/Sphingids in California; the three Californian Saturnia females also all have enormous eggs but lay just 70-80, and larva of two/three of  the species undergo four rather than five larval instars. We also hear that California Antheraea polyphemus also have larger eggs than those from other parts of the country. Thus, if the Coloradan cerisyi eggs turn out to be much smaller than our local Californian ophthalmica's it will further suggest that this large egg size of Ophthalmica is likely characteristic of the species or at least the Californian population, and may have to do something with the pattern we have been seeing.

Below are photos of the four Smerinthus cerisyi pupae as well as side by side comparisons with S. ophthalmica and another relatively closely related Smerinthin, Pachysphinx modesta.