Floral scent has been shown to elicit behavioral responses by butterflies which forage for flowers after receiving appropriate signals. In comparison with investigations about the role of floral scent, those of foliar odor are, however, very few. In this study, the foliar volatiles of Cinnamomum camphora (Lauraceae), which had been collected by air entrainment, exhibited activities toward Graphium sarpedon nipponum (Papilionidae) in both electrophysiological and behavioral tests. The volatiles were analyzed by capillary gas chromatography with electro-antennographic detection (GC-EAD). Two electrophysiological active compounds were found which were determined as nonanal and decanal by using gas chromatography-mass spectrometry (GC-MS). Female butterflies generally tend to show a greater EAG response than males to the headspace volatiles and EAG-active aldehydes. Two EAG-active aldehydes were found in attractant tests to be attractive to both sexes of the butterfly when treated individually. Although the difference between the sexes was not significant, the female butterflies' preference tended to be more active than that of the males.Key words: attractant; Graphium sarpedon nipponum; Cinnamomum camphora; nonanal; decanalThe sequence of behavior for most phytophagous insects during host plant selection is often in three different stages: orientation, approach, and assessment. 1)In trying to locate the habit of its host plant during orientation, olfactory stimuli alone, or in combination with visual cues are used by insects. These stimuli prompt the insect to initiate upwind flight. In the second step, the approach to the host plant may be triggered by an olfactory cue or by olfactory and visual cues. Olfactory cues play an important role for many insects in the first two behavioral steps. 2)Butterflies of the family Papilionidae are among the most common insect taxa.3) Research on this family has focused mainly on secondary metabolites, [4][5][6][7][8] which often act as oviposition and feeding stimulants. [9][10][11] These metabolites include amino acid derivatives, sugar-related acids, alkaloids, flavonoids, and hydroxycinnamic acid derivatives. 12) However, there have been few chemical ecological studies on the volatile compounds 13) relating to orientation and approach. To the best of our knowledge, investigations on volatile compounds has been largely reported for odors from the floral scent, [14][15][16][17][18][19][20][21][22] studies on the volatiles from foliage as an attractant being rare. 23,24) The common bluebottle, Graphium sarpedon (Lepidoptera: Papilionidae), is a species of swallowtail butterfly distributed throughout South and Southeast Asia. There are approximately 15 subspecies with differing geographical distributions. One of the subspecies, G. sarpedon nipponum, inhabits mainly southern Japan and the adult butterfly appears from May to October each year. This butterfly is a Lauraceae-feeding butterfly, especially preferring Cinnamomum camphora. Many males and females are commonly observed ar...

The acceptance of camphor tree (Cinnamomum camphora) as a host plant for the larvae of common bluebottle (Graphium sarpedon nipponum) was explained by the presence of feeding stimulants in the leaves. When the active methanol extract of C. camphora leaves was separated into hexane and water layers, both layers showed high feeding activities for the larvae of G. sarpedon nipponum. Bioassay-guided fractionation of the hexane layer resulted in the isolation of a highly active compound, which was identifi ed as α-linolenic acid by nuclear magnetic resonance spectrometry and gas chromatography-mass spectrometry.