Rearing notes for our two remaining Oregon Swallowtails (Papilio machaon oregonius). They were originally obtained as eggs from an Oregon breeder and reared indoors on fennel (Foeniculum vulgare). They pupated on 9/21 and 9/23.

Rearing Notes 10/4/16-10/7/16:

- Alan

Now that our Oregon Swallowtails (Papilio machaon oregonius) have pupated, we have the chance to compare them to our Anise Swallowtails (Papilio zelicaon), another machaon group swallowtail. 

From the moment we first got a good look at our first Oregon Swallowtail (Papilio machaon oregonius) to pupate on 9/21, we already got the sense that this phenotype was not your typical Anise Swallowtail (Papilio zelicaon) which we are much more used to seeing. 

For one thing, the oregonius chrysalis was huge: 1.3 grams for a male individual (on average, the smaller sex). 1.3 -- even 1.2 and some 1.1 -- gram Anise Swallowtails  are invariably female and the average Anise chrysalis including either gender straddles between 0.9 and 1.0 grams. Of 262 Anise chrysalises we had in August, only one chrysalis was larger than 1.3 grams at 1.5 grams; and there were only 11 1.3 gram chrysalises. Using these numbers, the percent of Anise chrysalises at or above 1.3 grams was only 4.58% (and we are quite confident that these were 100% female). While this is only one oregonius chrysalis we are looking at, the odds are highly in its favor that the oregonius are the larger species. 

While we had the feeling that the Oregon chrysalis didn't look quite like an Anise chrysalis (ignoring size), we couldn't quite put our fingers on it until today when the chrysalis fully tanned. Immediately, we noticed that the color was a bit off. It was a brown or dark morph chrysalis with a palish base and black stripes. While Anise chrysalises can also have a similar coloration, they are often much more mottled with the dark and light parts blending (sometimes looks brownish). Because we couldn't find a single exact match to the Oregon coloration out of our 70 or so brown morph Anise chrysalises, we took the closest match to do a side by side comparison. One obvious area of difference is in the wing pattern; the Anise chrysalises consistently have thicker and darker vein lines but reduces markings at the outer part of the wing as compared to the Oregon.

Another major difference between the Oregon and the Anise is the bump that protrudes from the back at the thorax. In the Anise, the bump is larger (wider) and is pointy (looks kind of like a horn jutting out) while in the Oregon it is more blunt. 

A third big difference is the horns on the head. Like with the thorax bump, the horns of the Anise are noticeably more pronounced and wider.

- Brian

Rearing Notes 9/13/16-9/??/16:

​9/21:

- Alan

Our fourth instar Oregon Swallowtail caterpillars (Papilio machaon oregonius) have ecdysed into fifth instar.

Our two remaining Oregon Swallowtail caterpillars entered apolysis yesterday and we thought they were going to ecdyse tomorrow since hadn't done after most of the day had gone by. However, around 10 PM, both of them ecdysed. Just like with zelicaon fifth instars, the fifth instar oregonius are now smooth bodied with no scoli. However, since both oregonius were already green in the fourth instar unlike most zelicaon which are black in the fourth instar unless subjected to high temperature and low humidity, the fifth instar oregonius are on the very green end of the color spectrum, having thick, vibrant green bands and thin black bands. As they get larger later in the instar and their cuticle stretches, they should become even greener. Size-wise, the oregonius look about the same size as zelicaon, though possibly slightly larger than average, but it is impossible to say since we only have two and no live zelicaon currently to compare to. 

- Alan

Rearing Notes 9/9/16-9/11/16:

- Alan

Admittedly, there hasn't been too many interesting observations to make about our Oregon Swallowtail caterpillars so far since they are almost identical to Anise Swallowtail caterpillars which we have raised thousands of. However, during the third instar, the caterpillars seemed slightly larger and lighter in color than typical anise swallowtail caterpillars raised under the same conditions and we suspected from the start that a main phenotypic difference between the two species' larvae was in their color based on internet searches. Anyway, today, two of our Oregon Swallowtail caterpillars molted into fourth instar, and we were amazed to see that both were green morph fourths, one being very green and the other somewhat whitish green. This is a clear difference between the two closely related species, as Anise Swallowtail caterpillars are typically black in the fourth instar when raised indoors and are only green when subject to very high temperatures and low humidity. In fact, we have only ever had a single indoor raised green morph fourth instar Anise out of thousandss we have reared. Thus, the fact that two of two of the fourth instar Oregon Swallowtail caterpillars reared under the same conditions as Anise are green is clearly not a coincidence and must be typical of the species.

Since the Oregon swallowtail caterpillars are already green in the fourth instar, we assume they will be very green fifth instars with extremely thin black bands since this is typical of fifth instars produced from green morph fourth instar Anises. When speculating from an evolutionary standpoint, it would make sense for the oregonius caterpillars to be more green in the final instar with very thin black bands since most non-umbel feeding Swallowtail larvae are green with no black bands. The machaon group Swallowtails diverged from Rutaceae feeding Swallowtails by jumping onto Apiaceae, or umbels (possible due to phytochemical stimulant similarities) and all have very characteristic black bands and yellow or orange spots in the final instar unique to other Swallowtail larva which make them quite cryptic on umbels. However, since switching over to umbels, some of the machaon group swallowtails such as oregonius now almost exclusively utilize Artemisia in the wild rather than umbels, again due to phytochemical stimulant similarities. Thus, since oregonius no longer feed on umbels any more, their once cryptic black bands are probably not very cryptic anymore and thus greener caterpillars with thinner black bands are more cryptic and have higher fitness. Don't quote us on any of this though, since these are pure speculations that came to mind when comparing oregonius to zelicaon. 

- Alan

Rearing Notes 9/5/16-9/7/16:

- Alan

Rearing Notes 9/1/16-9/??/16:

- Alan

Rearing Notes for our first instar Oregon Swallowtail caterpillars (Papilio machaon oregonius). These were obtained as eggs from an Oregon breeder and reared indoors on fennel (Foeniculum vulgare).

Rearing Notes 8/29/16-8/31/16:

- Alan

Our first two Oregon Swallowtail (Papilio machaon oregonius) eggs have hatched.

Since we received our Oregon Swallowtail eggs, many showed signs of development and began turning brown and eventually black today. Out of the 9 eggs, 1 was shriveled (infertile) 4 were yellow with mottled brown patches (developing), and 4 were black as of this afternoon, until  2 of the black ones hatched at around 5:00 PM and the other 2 at 11:00 PM. The caterpillars are nearly (if not exactly) identical to Anise swallowtail hatchlings. They are black with a white saddle and small scoli along the whole body. We found what we thought was tarragon (Artemesia), their preferred host, but it seemed that they did not recognize it, so perhaps we misidentified it. Instead, we put in some fennel which is a seldom used but utilizable host. 

- Alan