Papilio zelicaon Pupa Mass Data

We collected the mass data of our anise swallowtail (Papilio zelicaon) pupae.

---

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. 

​

---

Authors
Brian Liang

---