Jamaican Giant Swallowtail

P. homerus is endemic to Jamaica, which is located in the Neotropical realm. It previously occupied half of the 14 parishes of Jamaica but can only be found as two or three small populations today. While many researchers have previously claimed that there are only two remaining strongholds, one author argues that there are three distinct populations: a central, eastern, and western population.

Central population. The Central population has most likely disappeared. The last observation of P. homerus in this region was in 1925. This is also the least understood of the three populations. The region that they had inhabited consists of plateaus at an elevation of 600 to 1,000 m (2,000–3,300 ft). The population was located centrally around Mt. Diablo, which is located 70 km from both of the other populations. Thus, this population likely served as a key means of allowing gene flow between the three populations to prevent genetic bottlenecking, the genetic isolation of a subset of any given population. The population has been lost to anthropogenic habitat disruption. With deforestation and the expansion of developments bordering much of the remaining forest land, the climate of the region is more arid. This less than 100% humidity results in developmental defects in pupae reared in the lab. …

New larvae hatch from the egg, consume the chorion, and feed on the leaf of oviposition. They are typically found alone, but can share the same leaf with upwards of five other larvae. When the larvae reach the fourth instar, they move onto other, younger leaves to feed. Larvae have also been observed drinking water droplets after heavy rains.

Although, H. catalpaefolia and H. jamaicensis have been known to be the host-plants, the access to these plants now seem to be restricted. Currently, there is no confirmed larval food plant species known. However, oviposition has been observed on Ocotea species plants that are found in all three geographies known to have recently been occupied by the populations of Jamaican swallowtail.