Rewilding My Lot

Gulf Fritillary (Dione vanillae) butterflies and caterpillars are frequent visitors to my Scarletfruit Passionflower (Passiflora lanuginosa) vine. Our winter thus far has been exceptionally warm, and even in January I have blooms and visitors on this plant.

Gulf Fritillary butterflies are predominantly orange with additional black and white markings. They flit around a lot so photographing them is difficult, but I do have this video from a few days ago.

The caterpillars that I usually see on this plant are orange with black bristles, like this one I found in August 2025:

I was surprised recently to see a few caterpillars on the passionflower that had different markings. I saw several caterpillars at the same time that were predominantly black with a stripe of orange and white.

Of course I was curious as to what I was seeing. Were these also Gulf Fritillary caterpillars or something different? By recording an observation in iNaturalist and asking for help from the volunteer experts there, I got the answer back that these look like late instars of Gulf Fritillary caterpillars.

Gulf Fritillary caterpillars pass through five instar stages before they form a chrysalis. Looking at other reports, it does indeed seem to be the case that later instars are darker than the earlier ones, with their black more prominent than their orange. For instance, there is a series of photographs on this page. So my takeaway here is that different caterpillar instars might have different markings. I have seen slight differences with other caterpillars, e.g., Monarch, but hadn’t realized that the differences could be this significant.