32 TROP. LEPID. RES., 23(1): 32-38, 2013 CHANDRA ET AL.: Life history of Papilio schmeltzi NATURAL HISTORY OF FIJI’S ENDEMIC SWALLOWTAIL BUTTERFLY, PAPILIO SCHMELTZI (HERRICH-SCHAEFFER) Visheshni Chandra1, Uma R. Khurma1 and Takashi A. Inoue2 1School of Biological and Chemical Sciences, Faculty of Science, Technology and Environment, The University of the South Pacific, Private Bag, Suva, Fiji. Correspondance: [email protected]; 2Japanese National Institute of Agrobiological Sciences, Ôwashi 1-2, Tsukuba, Ibaraki, 305-8634, Japan Abstract - The wild population of Papilio schmeltzi (Herrich-Schaeffer) in the Fiji Islands is very small. Successful rearing methods should be established prior to any attempts to increase numbers of the natural population. Therefore, we studied the biology of this species. Papilio schmeltzi was reared on Micromelum minutum. Three generations were reared during the period from mid April 2008 to end of November 2008, and hence we estimate that in nature P. schmeltzi may have up to eight generations in a single year. Key words: Papilio schmeltzi, Micromelum minutum, life cycle, larval host plant, developmental duration, morphological characters, captive breeding INTRODUCTION MATERIALS AND METHODS Most of the Asia-Pacific swallowtail butterflies P. schmeltzi was reared in a screened enclosure from mid (Lepidopera: Papilionidae) belonging to the genus Papilio are April 2008 to end of November 2008. The enclosure was widely distributed in the tropics (e.g. Asia, Papua New Guinea, designed to provide conditions as close to its natural habitat as Australia, New Caledonia, Vanuatu, Solomon Islands, Fiji and possible and was located in an open area at the University of Samoa). These tropical Papilio utilize a diverse array of habitats the South Pacific, Suva. The enclosure measured 3.4 m X 7.1 such as forest, mountains, grasslands and suburban gardens. m X 1.8 m, and was large enough to allow observations while Within this genus, eggs are mostly laid singly, and many species standing inside the cage without causing significant disturbance feed on the members of Rutaceae. Many species exploit native to the butterflies. The enclosure was covered with two layers and cultivated Citrus species and some are considered pests of mesh: silver aluminum 1-mm² mesh covered the sides to (Parsons, 1999; Grund, 1999; Braby, 2000). allow maximum sunlight to pass through, and black polythene Papilio schmeltzi (Herrich-Schaeffer, 1869) is endemic mesh covered the top to provide shade and keep the inside of to the Fiji Islands and, due to habitat loss and predators, is the cage cool. Polythene mesh on the roof had periodic gaps currently undergoing significant population decrease (Chandra to allow sunlight. The floor of the cage was also covered with et al., unpublished). All type material and Herrich-Schaeffer’s aluminum mesh to prevent predators. Temperatures throughout records were destroyed during World War II (Robinson, 1975). the duration of the study ranged from 25 °C – 32.9 °C, and Existing information on P. schmeltzi is derived mainly from averaged 28.2°C. studies by Mathew (1885), Robinson (1975) and Hancock Flowering plants (nectar source for adults) were placed (1983a; 1983b). Mathew (1885) had studied developmental along one side of the enclosure and larval host plants on the stages of this butterfly but the descriptions are brief and only a other side in pots. Two native trees (Ficus sp. and an umbrella pupa and fifth instar larva are illustrated. Similarly, Hancock’s tree, Brassaia actinophylla) were provided for shelter, and (1983a; 1983b) accounts of the mature larva are limited. four rutaceous plants (Euodia hortensis, Murraya koenigii, Robinson (1975) and Hancock (1983a; 1983b) gave only short Citrus reticulata, and Micromelum minutum) were provided notes on morphology of adult P. schmeltzi. as potential host plants and to test oviposition preference. A detailed study of the life history of P. schmeltzi is Lantana camara (pink flowers), Ixora coccinea (red flowers), necessary in order to fully understand its population ecology Stachytarpheta urticifolia (purple flowers), Pentas lanceolata and to employ effective conservation programs. Recent (white & purple flowers), and Tagetes erecta (yellow flowers) investigations of P. schmeltzi have gained information on were used as enclosure nectar sources and to determine potential seasonal development of larvae by field observations (Chandra wild nectar plants. et al., unpublished). However, this approach was problematic A wild gravid female was released in the butterfly cage. because eggs of P. schmeltzi were scarce in nature; larvae were She successfully laid eggs on one of the host plants, and three found to occur in low numbers, and larvae that were encountered successive generations were subsequently raised. The number tended to already be in third or later instars. of eggs laid was counted daily, and the preferred host plant The aim of the current study was to rear P. schmeltzi in was noted. Immature stages were monitored while on potted captivity and to describe its life history, including information M. minutum to obtain estimates of survival. Durations of on inter-stage mortality, feeding behaviour and mating ecology. different developmental stages (egg, larval, and pupal stages) In addition to providing basic information on the ecology of and longevity of adults were recorded. this uncommon species, the potential for captive rearing of All morphological observations reported here are based on butterflies to provide specimens for augmentation of wild adults and different stages obtained from the reared generations populations is discussed. in the butterfly cage with additional information drawn from Mathew (1885), Van Son (1949), Hancock (1983b), Parsons (1999) and Braby (2000). Numbers of individuals of each CHANDRA ET AL.: Life history of Papilio schmeltzi TROP. LEPID. RES., 23(1): 32-38, 2013 33 2nd abdominal segment; an obscure brown stripe running along central dorsal abdominal segments. Fourth Instar: 21mm – 29.2mm in length, similar to third instar. Glistening dark brown with creamy white prothorax (extending laterally to mesothorax), 10 abdominal segments; all prolegs, ventrolateral abdominal area above is white. Fifth Instar: 29.7mm – 49.5mm in length, osmeterium is long and red; tubercles present on all thoracic segments, abdominal segments 1, 5 to 9; thorax slightly humped; all prolegs, ventrolateral abdominal regions are white. Larvae c exhibited colour dimorphism: green or striped. Green larvae dorsally uniform a b golden green or green with yellow-green lateral patches, transverse white to Fig. 1. Colour variation of P. schmeltzi eggs with age in the enclosure. Newly dark brown thoracic band with white ventrolateral line. Abdominal segments laid eggs (a), half way through egg stage (b) and eggs close to hatching (c). have white or brown ventrolateral band extending obliquely backwards dorsally over each of abdominal segments 4 and 6, margined with white above and below, that on segment 4 extending dorsally backwards to segment 5. For stage on which morphological observations are based and the striped larvae, body colour variable, green or orange brown with many white, measurements are given in Table 1. We recorded variation in yellow-white, yellow-green, yellow lateral streaks, transverse dark brown to black thoracic band. Abdominal segments with black or brown ventrolateral the colour and other morphological characteristics, duration of band extending obliquely backwards dorsally over each of abdominal segments pupa stage and time of day the adult emerged. Fecundity of 4 and 6, margined with white above and below; that on segment 4 extending adults was estimated by counting eggs deposited in cage and dorsally backwards to segment 5. V-shaped saddle mark dorsally on 3rd and oviposition rates were calculated by number of eggs laid daily 4th abdominal segments, extending laterally on to 2nd abdominal segment, distinctive; a structured, pale, small, v-shaped mark mid-dorsally on all for the first five days of oviposition. The number of larval instars abdominal segments; tubercles on abdominal segments 5 and 6 are prominent was assessed as well as duration of individual instars, and the black. overall growth rate. Courtship and mating behaviour including First four larval instars closely resemble fresh bird droppings as is typical mating frequency were observed. Longevity of adults and their of Papilio species, apparently to hide from potential predators, turning green in later instars (Henning et al., 1997; Parsons, 1999; Braby, 2000; Suwarno et interactions in a closed environment in cage were observed. al., 2007). P. schmeltzi early larval instars are closely related to P. godeffroyi Adult butterflies were observed in various behaviors such as (Mathew, 1885), P. aegeus (Braby, 2000) and P. fuscus (Parsons, 1999), as all feeding, coupling, chasing and oviposition. The camera used to are dark-coloured with anterior, middle, posterior parts having broad transverse take photos in the cage was a FujiFilm (FinePix A820) digital white bands on dorsal surface. P. schmeltzi and P. godeffroyi larvae have a prominent white V-shaped mark in middle of larvae but in P. schmeltzi white camera with 8.3 Mega Pixel recording and 4X Optical Zoom. V-shaped mark becomes bigger through growing instars unlike in P. godeffroyi (Mathew, 1885). P. schmeltzi larvae are distinguished from that of P. fuscus RESULTS AND DISCUSSION by presence of fleshy, subdorsal-branched