Papilio xuthus

Papilio xuthus is a member of the genus Papilio. It is of the family Papilionidae and order Lepidoptera. It was first introduced in Hawaii in 1971 from Japan or Guam. P. xuthus makes significant seasonal migrations over 200 km. There are three subspecies of P. xuthus: Papilio xuthus xuthus, Papilio xuthus koxinga, and Papilio xuthus neoxuthus. ==Description==

The Asian swallowtail is a mid-sized, yellow, prominently-tailed butterfly. The young caterpillar mimics bird feces and has a white and brown spot on its head. Experimental manipulation of wing coloration has been achieved through administration of the acid carboxypeptidase, Molsin. Injection of Molsin into 0-2 day pupae, butterflies had high amounts of black wing scales. These modified subjects had produced high amounts of melanin and papiliochrome II. Injection of Molsin into 3-4 day pupae shows no change in wing coloration. This indicates that P. xuthus likely has an acid carboxypeptidase of its own that naturally induces production of these pigments, and its action lasts during the first two days of pupation. Administration of a higher amount of acid carboxypeptidase to the pupae at 0–2 days induces an overproduction of pigmentation molecules, which leads to a high number of black scales. P. xuthus uses wing coloration and patterning to identify insects of the same species. Sexual behaviors are elicited from males by visual identification alone. Adult P. xuthus males were able to find odorless conspecifics, and while they do not discriminate by sex, they can identify a female once physical contact is made. ==Courtship and mating==

During the mating season, Asian swallowtail males fly through the foliage of trees in search of a mate. In addition, males use visual cues to conduct the mating ritual and are particularly attracted to closely spaced yellow patches on female wings. Multiple matings leads to an increased genetic diversity of swallowtail offspring. In addition, multiple matings allow females to produce a greater number of eggs, of which there can be up to thirty. Oviposition Female butterflies disperse when they are about to oviposit. They decide on the number of eggs they deposit in different subhabitats by certain criteria such as the quality of the subhabitat, the existing adult population in the area, the quantity of young leaves in the vicinity, the degree of sun exposure (females prefer sunnier areas), and host plant height. ==Mortality factors==

everted - lower: undisturbed Predation Some insects, such as the grasshopper Oeanthus longicauda, are capable of removing Asian swallowtail larvae out of their eggs before they hatch. Environment Aside from predation, larval mortality rate is also affected by diseases that appear to correlate with the duration of the rainy season. Long days of rain in autumn lead to the rotting of infected larvae. ==Foraging==

Asian swallowtail butterflies exhibit color vision which gives them the ability to differentiate objects of contrasting colors irrespective of brightness. Asian swallowtail butterflies show this color constancy even when the background light is yellow and red. • Poncirus trifoliata • Zanthoxylum species, such as the Japanese pepper tree (Z. piperitum), Z. nitidum and the Japanese prickly-ash Z. ailanthoides • Cultivated Citrus species such as mandarin orange and yuzu • Euodia ruaecarpa • Ruta graveolens (rue) • "Bauhinia" species, such as Hong Kong Orchid Tree ==Development and population dynamics==

Despite its wide distribution, populations of the Asian swallowtail remain at a stable, relatively low, level. There are typically four to five generations per year with the adults of the first generation emerging from mid-April to early May and adults of the second generation emerging in mid-June. P. xuthus will lay single eggs on leaves of host plants, allowing hatched larvae to feed on Poncirus trifoliata, Zanthoxylum ailanthoides and various citrus species. The larval stage lasts for approximately three to five weeks while the pupal stage is around two weeks. According to a study, the population fluctuation of the Asian swallowtail butterfly has been surprisingly stable compared to that of various other insects. The stability of the population appeared to be regulated by the population dynamics of egg the parasitoids, Trichogramma, and the pupal parasitoids, Pteromalus puparum, which maintained shorter life spans and generation times than the eggs of the Asian swallowtail. When the butterfly population reaches a high density, because of the shorter generational turn around of the parasites, intergeneration responses of the parasites are faster than those of the butterflies, resulting in a responding increased growth of the parasites. This creates an evolutionary stable system to keep the population of both the parasites and the host in check. It was also found that among the subpopulations studied, exchanges between each subpopulation helped to maintain the stability of the entire population as a whole. ==Gallery==

File:Egg of Papilio xuthus.JPG|Egg File:Papilio xuthus Larva 2011-10-15.jpg|Caterpillar File:Papilio xuthus Pupa 2011-07-16.jpg|Pupa File:Papilio xuthus and HIGANBANA Lycoris radiata.jpg|On Lycoris radiata ==See also==