Our final non-diapausing ♀ ​polyxenes asterius × ♂ zelicaon hybrid pupa eclosed into a crippled male. Fortunately, the important wing and body patterns are visible enough to compare to parent species, P. polyxenes asterius and P. zelicaon.

The hybrid eclosed today, and weak and small as it is, it could not expand its wins fully just like the first one. However, this one managed to expand enough for us to clearly see the wing patterns, unlike the first who's wings were completely crumpled. Below are sided by side live comparisons between the hybrid and the parent species, P. polyxenes asterius and P. zelicaon; all individuals are males. Though intermediate between the parent species and many traits, the hybrid superficially resembles polyxenes more due to the black (rather than yellow) ground color. However, all the yellow regions on the hybrid are darker than in polyxenes more closely match the shade in zelicaon.

Now let's get into the details, starting with the wings.

​Dorsal Forewing

The dorsal forewing of the hybrid is primarily black like polyxenes, though it is not quite as dark and is slightly brownish. The band of yellow spots in the middle is more or less consistent in width, unlike in polyxenes which typically tapers going upwards or like in zelicaon which is thick on both ends and narrower in the center. Also, The marginal yellow spots are somewhat intermediate of the parents, being more rectangular than polyxenes' but rounder than zelicaon's. ​

​Dorsal Hindwing

The dorsal hindwings of the hybrid are similarly intermediate between the parent species as the forewings are. They are primarily black, but the band of yellow spots is larger than in polyxenes. Also, the marginal yellow spots are larger and more crescent shaped than in the polyxenes of our lineage, more like in zelicaon.

Ventral Forewing

The central hindwing is again more polyxenes like that zelicaon, simply due to the black ground color (though again, slightly brownish rather than pitch black). However, the other traits seem more intermediate, with the band of spots in the middle being orange-yellow, rather than orange in polyxenes or yellow in zelicaon. The marginal yellow spots are longer lengthwise and more rectangular, similar to zelicaon, and not rounded or tear drop like in polyxenes.

​Ventral Hindwing

The ventral hindwing of the hybrid is perhaps the most interesting of the wings. It is again black in ground color rather than yellow. However, intermediate of the parents, it contains much more blue past the band of orange spots than in polyxenes, and less than in zelicaon. Also, the band of orange spots is lighter and more yellow than in polyxenes, and is more simplistic, lacking the orange spot on the discal cell like in zelicaon.

​Now, onto the body

Head & Thorax

Like mentioned in the previous post with the first hybrid, the yellow stripes on the head and thorax of the hybrid are short and small like in polyxenes, unlike the long, connected stripes in zelicaon. However, like other yellow regions of the hybrid's body, the yellow is darker than in polyxenes, and more like the shade in zelicaon.

​Abdomen

The hybrid abdomen is very interestingly intermediate between the parents which we briefly described it in the previous post already. On the hybrid, the abdomen very clearly has two rows of rectangular yellow spots laterally. This is intermediate between polyxenes and zelicaon, because in polyxenes, the abdomen has three rows of rounded yellow spots - two lateral and one dorsal, and in zelicaon there are two solid yellow stripes rather than  rows of spots. The placement of the top row of yellow spots in the hybrid is also intermediate between the location of the dorsal and top lateral row in polyxenes, and right in the middle of where the larger solid yellow stripe in zelicaon is.

​Authors
Alan Liang

Now that most all of our anise swallowtail (Papilio zelicaon) larvae have pupated, we have a lot of pupa mass data. We have a very large sample size that includes larvae of many different lineages, so it should be fairly representative of our region's population when fed on fennel (Foeniculum vulgare), which they almost always use in the wild already. The only concern was our accuracy in sexing the pupae. For some reason, anise pupae are particularly ambiguous compared to other swallowtails we have reared and because the pupae were weighed on the day of pupation, some of them still had not completely gotten into shape which could have made it hard. But even with an 80-90% accuracy, it was still quite clear that females are larger on average than males when you consider a whopping t = 90637 (df = 179; n = 181; p<0.0001) in a 2-sample t-test for the difference in means. A table summarizing our data is shown below. 

Summary Statistics for Papilio zelicaon Pupa Mass
                   Mean                   Std Dev                  Median      Min      Max     N  
Male          0.9612903226       0.1132832714           1                  0.7         1.2        93
Female      1.123863636         0.1259395204          1.1               0.9         1.5        88
All               1.040331492        0.1444449167         1                  0.7         1.5        181

Although the difference in size between the two sexes was statistically significant, the difference isn't huge in real life, especially with the large standard deviations. Just eyeing them, the only ones that can be instantly sexed without looking at the genitalia are the massive females; even though there is only a 0.16 difference in means, the difference in maximums was 0.3. Disproportionately high female potential seems to be a common trend in the species we have reared. 

What surprised us as we were collecting was how many of the pupae were exactly 1 gram, regardless of sex. For this kind of data, it would definitely have helped to use a more precise scale (perhaps to .001). This would have made the curve much smoother in the charts below and may have helped in showing the difference in size between the sexes. It is especially strange that so many of the females were 1 g, making it is hard to draw any conclusions from their distribution other than that we may have messed up. The male curve and the combined curve are both much more unimodal albeit sightly skewed. 

​

Our male ♀ Papilio ​polyxenes asterius × ♂ Papilio zelicaon hybrid finally eclosed, but unfortunately did not expand its wings.

We are extremely disappointed to say that our ♀ Papilio ​polyxenes asterius × ♂ Papilio zelicaon hybrid male eclosed today but could not expand its wings fully. We don't know why it became crippled or if hybridization could have caused it, though usually the males of machaon group hybrids should have no problem eclosing. Despite the crumpled wings, it is still possible to see the body and the general pattern on the wings. We tried to get shots from many different aspects, shown below.

From what we can see, the hybrid appears to resemble polyxenes more so than zelicaon. Both fore and hind wings have a considerable amount of yellow, but it is hard to say exactly how much since they are not fully expanded. The males of the parent species both have yellow on their wings, with zelicaon having more. The hybrid definitely seems to have less yellow than a zelicaon would have and looks more like polyxenes. However, perhaps if the wings were expanded, there would actually be a lot more yellow than it looks, and perhaps some of the grayish looking parts could expand to a yellow-gray, intermediate of the parent species. We do not know.

As for the ventral aspect the wings, they again seem to resemble polyxenes more, with the forewing having only small amounts of yellow and the hindwing having orange spots. However, probably the orange spots on the hind wing will expand into a pale yellow orange based on how light they are even when not expanded, which would be intermediate of the parent species, since polyxenes' spots are well-defined and dark, while zelicaon only have traces of orange.

Looking at the body - mainly the abdomen, the hybrid again resembles polyxenes slightly more. In the parent species, polyxenes has several rows of yellow spots down the length of its abdomen while in zelicaon, it is a single solid yellow stripe on each side with a poorly defined solid stripe on the ventral side. The hybrid very clearly has rows of spots rather than solid yellow, but the spots appear to be slightly larger and more rectangular and "dash" like than than in polyxenes. The head and thorax region looks more polyxenes as well. In polyxenes, there are broken pale yellow spots on the thorax while in zelicaon it is two solid dark yellow stripes. The hybrid has spots rather than solid stripes, but they appear slightly thicker and darker than normally would be in polyxenes. 

​Authors
Alan Liang

The hybrid is almost here now. Just another day and it should be out. As of tonight it is pharate and the wing patterns can already be seen. We currently also have pharate zelicaon and a close to pharate polyxenes (the two parent species) for comparison, plus an actually pharate male and female polyxenes photo from a month ago (bottom center). All pupa shown are male except for the female polyxenes.

The main thing to compare here is the amount of yellow on the wings. It's the number one difference that separates zelicaon and polyxenes adults (and many other closely related western and eastern swallowtails) and thus the also main area of focus on the hybrid wing patterns as well. In zelicaon, the fore and hind wings of both males and females are predominantly yellow. In polyxenes, both males and females are predominantly black, but the male has a thin row of yellow on both fore and hind wings while the female is almost entirely black. See Papilio zelicaon and Papilio polyxenes asterius Side by Side Pictures for a visual.

On the developing pupae, the zelicaon very clearly has a large yellow portion on the hindwing while the male polyxenes only has a small strip of yellow spots. The hybrid, on the other hand appears to be a perfect intermediate, having the yellow portion of the zelicaon wing pattern but rather than a bright rich yellow, it is partially masked by black, turning it into a greyish yellow. The hybrid also has the marginal row of yellow spots, a trait shared by both parent species.

​Authors
Alan Liang

An anise swallowtail (Papilio zelicaon) with particularly large, crescent-shaped marginal yellow spots eclosed today.

We probably seen hundreds of zelicaon in our time here, and we've noticed quite a lot of variation in the adult wing patterns. One of the most variable traits is the marginal row of yellow spots. The spots can be big or small; rounded, rectangular or crescent-shaped; short or elongated - you get the point. Today, we had a female eclose, and it had some very large marginal spots - some of the largest we've seen. What's more was that they were very crescent-shaped, especially the ones on hindwing, with the crescent on the tail cell stretching deep into the tail. It happens sometimes in individuals with very crescent shaped spots, but they're really large on this one. 

Below is a comparison to a more typical looking zelicaon (right) with smaller, less crescent-shaped marginal yellow spots (though the ones on the forewing are perhaps slightly smaller than usual).

Rearing notes for anise swallowtails (Papilio zelicaon). Originally obtained as eggs or larvae in Albany, El Cerrito, and Berkeley California.

Rearing notes 8/2/17-7/10/17:

Authors
​Brian Liang

We released another wave of anise swallowtails (Papilio  zelicaon) .

The zelicaon just keep eclosing and eclosing. We've already hand-paired so many and released dozens earlier this week and today we went and released and another few dozen. Some had been sitting inside the tub for a few days already and were very thirsty upon release. They quickly flew straight to the many thistle plants in our front yard that are now in full boom and nectared for many minutes. The butterflies are extremely attracted to purple colored flowers, even ones that aren't even nectar flowers. We have a large Rose of Sharon (Hibiscus) covered in large purple flowers in our front yard, and we constantly see zelicaon (and rutulus if we're lucky enough to see one) attempt to nectar from it, though they are unable to suck up the nectar from these flowers. 

While releasing the zelicaon, we also spotted a gray hairstreak (Strymon melinus) and gulf fritillary (Agraulis vanillae). We didn't get a shot of the gulf, but it was nectaring on white star jasmine flowers (Trachelospermum jasminoides). Unlike swallowtails, they seem to be attracted to a wider color range of flowers. 

​Authors
Alan Liang

Anise (Papilio zelicaon) and western tiger (Papilio rutulus) swallowtails can be hand-paired but copulation is evidently unsuccessful.  

Just when we thought that the western tiger swallowtails (Papilio rutulus) were completely out for the season, we found a newly eclosed male nectaring at our neighbor's bougainvillea (Bougainvillea), a flower that seems quite popular with swallowtails. On of the two rutulus pupae that we just reared is clearly diapausing whereas the other one seemed to be days away from eclosion when we cracked it open and found a dried out butterfly. Any sort of flight in August is clearly partial second from late eclosers in the spring.

This male would have been perfect if the pupa we had didn't die because it was a female. In fact, before we found out that it was dead, we had went out on multiple occasions to search for a male to hand-pair it with. 

I suppose, this is slightly uncalled for, but out of curiosity, we attempted to pair the male with a female anise (Papilio zelicaon). It took a minute or so, but the male quickly found a way to clasp on even though it appeared to be much to large for the female. After a few moments, the male calmed down and was holding on tightly enough that they could not be broken. This was easier to execute than some pairings between two P. zelicaon! The female, on the other hand, evidently sensed that something was wrong and kept trying to break free. We don't usually see uncooperative females when they are paired with the correct species. 

When they separated (after what was an appropriate amount of time), we left the female by herself in a dark place for a day before setting her out to see if she would lay eggs. After three days of no activity, we concluded that the hand-pairing was completely unsuccessful. We have seen females lay heaps of infertile eggs as long as the pairing actually happened (but the male was no good), but no eggs at all often indicates that the female is virgin. 

Although, there aren't too many really unique individuals, we tried to get as many different looking ones in these pictures. We only had about a dozen or two at the time (the rest were either released or put to work laying eggs), so there wasn't as much variety as we would have liked, but there are still some interesting things to see. A lot of variation exists in the shade of yellow, amount of black and blue, and the also the shape of the yellow at the edges of the hindwings. Some of them have crescent shaped yellow pieces on these edges whereas some of them are just flat. 

Photos of some of our many anise swallowtails (Papilio zelicaon) that we released today. They were originally obtained as eggs or larvae in Albany, El Cerrito, and Berkeley California.

Over the past few days, we had several dozens of zelicaon eclose. We made pairings with many of them and have the females laying eggs in a cage now. Since we no longer have any use of them, we decided to release all the spent males and other individuals we never used for pairings. We took this opportunity to get some photos of them (all posed on thistle).