Found Cresphontes on Rue at the Cornell Botanic Gardens

After locating rue (Ruta graveolens) at the Cornell Botanic Gardens, we were able to find eastern giant swallowtail (Papilio cresphontes) larvae.

---

After our first trip to the Cornell Botanic Garden yesterday, we realized that many butterflies such as Papilio cresphontes and troilus are common and still in flight here. Thus, on our visit today, we tried to locate some of their hosts in order for to attempt getting eggs out of the females we caught yesterday, and also to find any larvae or eggs that might be on them. 

At first, we spent a long time trying to find troilus hosts, spicebush (Lindera benzoin) and sassafras (Sassafras albidum), but we simply couldn't (makes us wonder why the butterfly was even here??). We later asked one of the workers there who told us there wasn't spicebush in this section of the garden, but there was some in the arboretum, but that was far from here and a storm was due in half an hour.

​We then quickly moved on to searching hosts of the Rutaceaea feeding cresphontes. We knew there was some lemon trees (Citrus limon) there, but they were small and not very good, so there wasn't much hope of finding eggs or larvae on it. Instead, we tried looking for hop (Ptelea trifoliata), prickly ash (Zanthoxylum americanum), or rue (Ruta graveolens). Based on the Botanic Garden plant database, there was no prickly ash and the few hop trees they were supposed to have were apparently in a different section quite far from where we were looking. We thus forgot about the hop and prickly ash and tried to find some rue, which they supposedly had three patches of in the herb section.

After searching for probably much longer than we should've (half an hour at least?), we located two of the three patches, which in retrospect were actually just in plain sight. We quickly scanned the first patch, but surprisingly found no eggs or larvae, despite that the butterflies (both sexes) were always flying around the garden (while we were searching, we actually caught a male cresphontes drinking nectar, though we have little use of him). When we got to the second patch, we were delighted to see that there was a second instar sitting right in front of us on the upper side of a leaf. We eagerly searched the pants for more, but all we could find was a dead second instar on a leaf (no idea what the case of mortality was). The single live larva was good enough for us though - we had never seen the larvae of this or related Heraclides group species in real life until now. The larva is a perfect dropping mimic (much more convincing than other Papilio larvae we have seen), being shiny with blotches of white on the dorsum of the abdomen and rear. The thorax is also extremely enlarged and shaped like a snake head. We collected the larva in a dish and started heading back as the storm was beginning.

While looking for the cresphontes and troilus hosts, we spotted a bunch of the common stuff again, like melanoplus and band-winged grasshoppers, monarchs, skippers, red-spotted purples, etc. There were also a terrifying amount of Heminoptera and Diptera here compared to at home, with probably hundreds (thousands?) swarming the flower bushes in the garden.

We also took a few shots of the garden right before we left if you were wondering how it looked.

---

Authors
Alan Liang

---