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Desert Black Swallowtail [Papilio poyxenes coloro] Rearing Images

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This female came from the Dead Mountains on March 6th, 2005. I had hopes of getting some eggs and raising a brood of these swallowtails. Getting swallowtails to oviposit in captivity can be difficult at best. I have either stumbled onto the magic combination, or just got lucky, as I managed to get 33 eggs. My procedures have been repeated several times since this initial attempt, to verify cause and effect. I've documented the events and conditions below for others to try.

The female was captured on Monday at about mid-day. She spent the remainder of the trip (about 48 hours) safely packed in a glassine envelope at ambient temperature until Wednesday mid-morning when I removed her. She was a bit weak and pretty hungry when removed from the envelope. She crawled around but didn't try to fly and probably couldn't. I had no honey onhand so I fed her a solution of about 10% (granulated) sugar in water. She drank a bit and then laid 2 eggs almost immediately just sitting on a plastic container.

I placed a sprig of [what I thought was] Thamnosma (Turpentine Broom) in front of her to encourage further ovipositing. Turns out it was some other smelly purplish plant, so apparently no host plant was necessary! In any case, she was only willing to drink more sugar water, and crawl/flutter around a bit. This routine cycled off and on during the day. Her abdomen swelled noticably from all the nectaring, but she did not oviposit any more. At the end of the day I placed her back in the envelope so she wouldn't beat herself up.

Thursday morning I began trying different strategies; keeping her close to the [not Thamnosma] plant sprigs, feeding her off and on, and letting her bask under my 23w compact fluorescent desk light. She seemed to enjoy being very close to the light (about 2") where it was really warm and the light was intense. She would sit still with her wings open to "sun" herself for up to 10 minutes before becoming restless. About mid-day I acquired some honey and mixed-up a batch of 10% honey-in-water, which I began to feed her instead of the sugar water. No ova were deposited at all. Back into the envelope she went for the night.

Friday morning, I took her out of the envelope and fed her the honey solution, and she immediately laid an egg on my finger. No host plant (wrong kind or not) was anywhere near. The feeding, basking, crawling/fluttering AND egg laying cycles continued - she oviposited one egg about every 5 minutes, mostly while crawling on my fingers, for 20-30 minutes, then rested for 15-20 minutes. After several hours and 27 eggs she stopped ovipositing for the day. I placed her back into the envelope.

Saturday morning I repeated the same procedure as before but was only able to get 4 eggs out for the day. She was obviously getting worn down. By Sunday morning she could barely move and finally died sometime Sunday afternoon.

Summary observations: A lot of nectaring seems to have a delayed effect of stimulating ovapositing on the following 1-2 days. Exposure to bright light and warmth also has a positive effect. Host plant was not be needed at all, since the sample I brought back turned out to be the wrong plant! Keeping her confined in an envelope when not actually feeding, ovipositing or basking seemed to provide a resting period so that when she got out of the envelope she'd be ready to oviposit right away. 3-11-2005

The eggs are bright yellow when first laid. After about 5 days they begin to turn orange, first as a band, then darkening even further to a deep amber. Finally, about one day before hatching they are completely black as the developing larva inside is visible through the almost completely transparent egg shell.

8 to 10 days later the eggs began to hatch... (3-19-2005)

The eggs were placed in a "hatching tray", made from a small paper cup and hung from the host plant. When the larvae hatch they don't have far to crawl to find fresh lunch! In this case, a Fennel sprig is poked through a small hole in a medicine bottle filled with water. It's important to prevent the larvae from entering the water as they will drown if they do. The larvae and container setup are pictured below... (3-19-2005)

...few shots of an early 2nd instar larvae on 3-20-2005

On 3-27-2005, the largest is now almost an inch long and growing rapidly. The two left images show the color and pattern. The two right images show a 2nd instar molting into 3rd.

Here is a very freshly molted 3rd instar larva. Note the lighter colors of the head capsule and legs. Within about 15 minutes, these areas take on their normal black coloration. 3-30-2005

On 4-1-2005, they are growing rapidly. A large 4th instar is shown with a 3rd instar, and displays it's "horns" when disturbed.

4-3-2005 - I Visited the foothills North of the Dead Mts. again and was able to locate some larvae on Thamnosma montana. Finally got the foodplant right! Notice how well the larvae blend in even though they have a very different color pattern than the plant itself. Some pictures of the host plant and a 15" net for scale are also shown. Many of the larvae shown are 4th and 5th instars.

These larvae were nice enough to sit still for some "mugshots" to show the variation in coloration and pattern. 4-4-2005

By 4-7-2005 a number of the "collected" larvae had begun to pupate. Like most Leps, the mature 5th instar larvae makes one last messy poop as it purges its gut, and then begins to wander around, searching for a secluded place to pupate. The core of the host plant and under nearby rocks make ideal locations, because they provide protection from predators and the elements. In captivity, a paper bag makes a suitable place to pupate. The larvae will suspend themselves in typical Swallowtail fashion and shed their skin one last time as they pupate in 1-3 days.

The sequence of frames below shows the pupal shedding process.

These shots show the original batch of larvae raised from the eggs of the female at the top of this page. By 4-8-2005 they are getting pretty large and mostly overwhelming this fennel bouquet. This batch will be carefully monitored to see what percentage of dark and light forms emerge, since they all originated from the same parents. The female was a yellow (light form) and the male was unknown.

Additionally, some pupae are green and some are brown. It's been suggested that a higher percentage of green pupae emerge in the same year, and more brown pupae tend to overwinter. The results of these two batches will be detailed below.

The first 3 shots show a larva suspended in preparation for pupation on 4-19-2005. Many swallowtail species suspend themselves in this manner. The 4th image shows a larva in the process of shedding its final skin but it died during the process on 4-20-2005

This home-made box is handy to monitor pupae while they develop. Freshly emerged adults can easily be spotted and removed before they can damage themselves. The pupae are pinned in place, either by the substrate on which they pupated (paper bag), the silk pad they spun and attached themselves to, or a tape holster to hold them upright. The inside of the box is lined with tulle netting so that they can hang properly to inflate their wings.

In the center of the box is a "humidifier" made from a paper towel, Q-tips, and jar lid. The lid is filled with water and absorbed and evaporated by the paper towel. The increased humidity is intended to simulate spring and summer rainfall and encourage eclosure. The entire enclosure is made from a pourous material such as cardboard, which prevents condensation (important!) even though the box is basically non-ventilated. 4-20-2005

These images show some of the color variations in coloro pupae. They range from green with yellow spots, to a dark grey color. A few pupae are about ready to emerge, and the wing pattern can be clearly seen through the nearly transparent pupal case on 4-20-2005. Empty pupal cases and one suspended larva on are shown in the right photo on 4-21-2005.

Swallowtails are easy to feed - just mix 10% honey in water and serve as shown. You can use a toothpick or insect pin to uncoil the butterfly's tongue into the solution. If they are hungry, they will immediately stop moving and feed for up to 10 minutes, unless disturbed. Here is shown a fresh form "clarki" male feeding with a female rutulus on 4-21-2005.

While feeding, I took the opportunity to shoot some closeups of the coloro's face using a jeweler's eye-loupe held to the lens of a digital camera. The depth of field is greatly reduced at such high magnification but the image is still interesting. 4-25-2005

After an attempted hand pairing of a dark male and female, the project comes full-circle with this new generation preparing to lay eggs. The egg-laying setup is pretty strightforward - keep them warm, in bright light, and feed them regularly. It doesn't take much encouragement to get females to oviposit, but a sprig of Rue is provided anyway. If warm and laden with eggs, the females will oviposit about once every 10 minutes on average. Apparently it takes some internal processing before egg is ready to be oviposited. 4-25-2005

Females will oviposit even if not successfully mated, so it will be about 10 days before I know if my hand pairing will result in a subsequent generation of coloro or not! 4-25-2005

I happened to have a rutulus egg onhand as the coloro began ovipositing, so I thought it would be interesting to show the difference in size between the ova of the two species. 4-25-2005

By 4-26-2005, 7 yellow form females had emerged, and only two males. One male was a yellow form and the other a dark form. Interestingly, all the pupae which have emerged up to this point have been green ones. These two adult female yellow form specimens show some variation in amount of black in the wing pattern.

On 4-27-2005, this female form "clarki" emerged and I was able to capture a few nice hi-res images...

At this point the project is essentially complete, although additional coloration and timing data will be added as the remaining pupae emerge.

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