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Male adult butterflies of many species have characteristic odors originating from the disseminating organs known as androconia. Despite the fact that androconia exist in several species, there have been few investigations on adult scents from the lycaenid species. Celastrina argiolus ladonides(Lycaenidae) is a common species in Eurasia. We have reported that male adults of this species emit a faint odor, and the major components causing this odor have been newly found in the Insecta. By using field-caught individuals, we determined the chemical nature and location of this odor in the butterfly. Gas chromatography–mass spectrometry (GC–MS) analyses revealed that two lactone compounds, lavender lactone and δ-decalactone, are present in the extracts of males but absent in those of the females. On an average, approximately 50 ng of each compound was found per male. Chiral GC analyses performed using enantiomerically pure standards revealed that the natural lavender lactone was a mixture of two enantiomers with an R/Sratio of 32:68, whereas the natural δ-decalactone contained only the R-enantiomer. When the analyses were conducted using different parts—forewings, hindwings, and body—of three males, the lactones were more abundantly found on the forewings and hindwings than on the body. Microscopic observation of the wings demonstrated that battledore scales known as androconia are scattered on the upper surface of both the wings of C. argiolus ladonidesmales. These results indicate that the specialized scales on the wings of males serve as scent-disseminating organs.

Abstract: How to acquire sufficient quantity of nitrogen is a pivotal issue for herbivores, particularly for lepidopterans (butterflies and moths) of which diet quality greatly differs among their life stages. Male Lepidoptera often feed from mud puddles, dung, and carrion, a behavior known as puddling, which is thought to be supplementary feeding targeted chiefly at sodium. During copulation, males transfer a spermatophore to females that contains, besides sperm, nutrients (nuptial gifts) rich in sodium, proteins, and amino acids. However, it is still poorly understood how adults, mostly nectarivores, extract nitrogen from the environment. We examined the availability of two ubiquitous inorganic nitrogenous ions in nature, viz. ammonium (or ammonia) and nitrate ions, as nutrients in a butterfly, and show that exogenous ammonia ingested by adult males of the swallowtail, Papilio polytes, can serve as a resource for protein biosynthesis. Feeding experiments with 15N-labeled ammonium chloride revealed that nitrogen was incorporated into eupyrene spermatozoa, seminal protein, and thoracic muscle. Ammonia uptake by males significantly increased the number of eupyrene sperms in the reproductive tract tissues. The females also had the capacity to assimilate ammonia into egg protein. Consequently, it is evident that acquired ammonia is utilized for the replenishment of proteins allocable for reproduction and somatic maintenance. The active exploitation of exogenous ammonia as a nutrient by a butterfly would foster better understanding of the foraging and reproductive strategies in insects.

Adults of Papilio protenor demetrius emit a faint odour; the male odour is notably stronger than that of the females. The extracts of whole individuals of each sex comprised 53 compounds regarded as cuticular lipid components, of which the 17 major compounds were straight-chain alkanes and alkenes with 23 - 31 carbon atoms, higher fatty acids, long-chain aliphatic ketones, squalene, and cholesterol. However, highly volatile compounds were not detected in the whole individual extracts. Eight of the 17 major compounds showed a significant sex difference in relative abundance per individual. Principal component analysis, using the major compounds as variables, revealed a marked sexual dimorphism in the chemical composition of cuticular lipids. From the extracts of 10 dissected individuals of each sex, 21 highly volatile compounds were identified in amounts of less than 200 ng/individual. Among them, linalool and 2,3-butanediol showed a significantly larger amount in males than in females, indicating that the adult odour is also sexually dimorphic. Moreover, both sexes shared several odoriferous compounds, such as heptanal, nonanal, methyl salicylate, benzyl alcohol, and benzoic acid. The faint odour of P. protenor adults, perceivable by the human nose, appears to originate from these volatile compounds

Abstract: Adults of some butterfly species have odors, several components of which are known to have pheromonal or defensive functions. Little is known about the odors of hesperiid butterflies, however. Erynnis montanus (Hesperiidae), especially male adults, emit a pungent odor that is detectable by the human nose. Chemical analysis has revealed that crude extracts of wild individuals contained 10 volatile substances, of which docosane and heneicosane were the main components. Because males contain a significantly larger amount of p-cresol than females, this aromatic compound is characterized as a strong male odor. At the end of the adult occurrence period, p-cresol decreased substantially in each male. Benzothiazole, identified for the first time in lepidopteran adults, was present in both sexes in almost equal amounts. Among the 10 volatile substances detected in males, biased distribution in the wings rather than the body was observed for benzothiazole, heptanal, and p-cresol. Male adults have androconial organs in the costal part of the forewing on which benzothiazole and p-cresol tended to concentrate. However, these compounds were detected not only in other parts of the forewing but also in the hindwing and body, suggesting the presence of undiscovered scent-producing organs.

Abstract: We compared the chemical compositions of the osmeterial secretions of fourth and fifth (last) instars of eight swallowtail species of the tribe Papilionini. Four species (Papilio demoleus, P. polytes, P. paris, and P. macilentus) are Asian Rutaceae-feeding swallowtails. The other four (Chilasa epicydes, C. agestor, P. troilus, and P. glaucus) represent more distant clades within the Papilionini and species with larval hosts in other plant families. We conducted a quantitative analysis for six species, but only qualitative analysis for P. glaucus and C. agestor. In all eight species, regardless of larval host plant, secretions of the fourth instar principally consisted of mono- and sesquiterpene hydrocarbons, whereas those of the fifth instar comprised aliphatic acids and their esters. Consistent with earlier findings, our results suggest that this “heterogeneous” pattern of osmeterial chemistry, not seen in other tribes, may characterize the Papilionini as a whole. Unlike those of most Papilio species, the fourth and fifth instars of Chilasa species resemble each other in body coloration. Thus, the heterogeneous osmeterial pattern is not necessarily associated with color change in papilionid larvae. The major terpenoids identified in fourth instar larval secretions from the six species were α-pinene, sabinene, β-myrcene, limonene, β-phellandrene, (Z)-β-ocimene, (E)-β-ocimene, p-mentha-1,4(8)-diene, β-elemene, β-caryophyllene, (E)-β-farnesene, (3Z,6E)-α-farnesene, (Z)-α-bisabolene, germacrene-A, (E)-α-bisabolene, and germacrene-B. The profiles for individual species differed both qualitatively and quantitatively from one another, and certain species also secreted methyl 3-hydroxy-n-butyrate and oxygenated sesquiterpenes in relatively large proportions. Secretions from fifth instars were composed of varying proportions of isobutyric, 2-methylbutyric, and acetic acids, and methyl and ethyl (minor) esters of both isobutyric and 2-methylbutyric acids. The heterogeneity of osmeterial chemistry in the tribe Papilionini may represent fine-tuning of chemical defense in response to shifting predation pressures as the larvae age and grow.

Abstract Males of the chestnut tiger butterfly, Parantica sita, secrete danaidone as a major component from the alar androconial organ (sex brand). Since danaidone has been postulated to be derived from various pyrrolizidine alkaloids (PAs), which males ingest as adults from PA-containing plants, we conducted oral administration tests of several PAs to examine their availability for danaidone production by P. sita males. Males fed with a mixture of intermedine (80%) and lycopsamine (20%) produced danaidone at an average of 25.7 µ g per individual, which was comparable to that found in field-caught males. In contrast, a smaller amount of danaidone (5.7 to 7.0 µg/male) was formed when males ingested retronecine or heliotrine, and those fed with an HCl salt of monocrotaline or retrorsine produced only traces of danaidone (< 0.5 µ g/male). In addition, males showed a strong feeding response to intermedine/lycopsamine, whereas the other PAs elicited no positive feeding behavior. These results indicate that, unlike the arctiid moths, P. sita males can only successfully convert limited chemical types of PAs into danaidone, and further suggest that in the field, males selectively ingest particular PAs that are readily transformable into danaidone.

Host-plant chemicals responsible for egg-laying by the chestnut tiger butterfly, Parantica sita, were identified from one of its hosts, Marsdenia tomentosa. Ovipositing females responded positively to a methanolic extract of the plant. Solvent partitioning of the extract and oviposition bioassays indicated that the active principle resided in the aqueous fraction. Further activity-directed fractionation of the water-soluble constituents by various forms of column chromatography led to the isolation of several saturated and unsaturated cyclitols together with their glycosides. Of these, conduritol A, a predominant cyclitol present in the plant, moderately stimulated oviposition, while conduritol F 2-O-glucoside, although present in a very small amount, evoked a stronger response from females than conduritol A when tested at the same dose. In contrast, its aglycone, conduritol F, which was also a trace component, was almost inactive by itself. However, the oviposition-stimulatory activity of conduritol A was significantly enhanced when tested in combination with a small quantity of conduritol F. Addition of a small quantity of conduritol F 2-O-glucoside to conduritol A resulted in a substantial elevation in female responses. Consequently, the synergistic action of a large amount of conduritol A and small amounts of co-occurring conduritol F and its glucoside can account for the stimulation of egg-laying by P. sitaon M. tomentosa.

In nature, Papilio polytesutilizes a limited range of rutaceous plants as hosts. We isolated and identified oviposition stimulants for the butterfly from the foliage of its primary host plant Toddalia asiatica. Females readily deposited eggs in response to a methanolic extract of the plant. Partition of the extract with organic solvents revealed that chemicals responsible for eliciting egg-laying resided in a water-soluble fraction. Further bioassay-guided fractionation of the active fraction by column chromatography, preparative TLC, and HPLC led to the isolation of two oviposition stimulants. One was isolated from an amphoteric fraction and identified as trans-4-hydroxy-N-methyl-L-proline [(−)-(2S,4R)-4-hydroxy-1-methyl pyrrolidine-2-carboxylic acid; HMP]. The other, isolated from an acidic fraction, was identified as 2-C-methyl-D-erythronic acid [(−)-(2R,3R)-2-methyl-2,3,4-trihydroxybutanoic acid; MEA]. HMP alone evoked significant oviposition-stimulatory activity, although this was much lower than that of the original water-soluble fraction. MEA, on the other hand, alone did not elicit positive responses from females. However, HMP, when assayed in combination with MEA, markedly enhanced the female response, and the mixture was as active in stimulating oviposition as were the original water-soluble fraction and the plant foliage. We conclude that HMP is a substance crucial for host recognition by females, while MEA is a synergistic stimulant involved in host recognition and/or preference.

Papilio polytesutilizes only a few plant species of Rutaceae as hosts in the field. We examined in detail the acceptability of Toddalia asiatica(a major host plant) and three other potential rutaceous hosts, Murraya paniculata, Melicope triphylla, and Phellodendron amurense, for ovipositing females of the butterfly. Female responses to the foliage, methanol extracts, and partitioned fractions from these plants were assayed for the presence of oviposition stimulants and/or deterrents. Larval survivorship on these plant species was also compared as an estimate of fitness. The foliage and a methanol extract of T. asiaticareadily induced egg‐laying, while females responded moderately to the foliage and a methanol extract of P. amurense. By contrast, ovipositing females only marginally accepted Me. triphyllaand completely rejected Mu. paniculata. Further experiments to test the biological activity of fractions derived from the respective plant species revealed that T. asiaticacontains potent oviposition stimulant(s) and that weak stimulant(s) are present in P. amurense. Poor or negative oviposition responses to both Me. triphyllaand Mu. paniculataproved to be attributable to strong deterrent(s) present in these plants. Larvae performed very well on T. asiaticaand P. amurense, whereas larval mortality was much higher on Mu. paniculataand Me. triphylla, suggesting the involvement of antifeedant(s) or toxic substance(s) in these plants.

Adults, particularly males, of a papilionid butterfly, Papilio machaon hippocrates, emit a fairly strong scent perceivable by humans. We have identified a variety of volatile compounds (hydrocarbons, alcohols, aldehydes, ketones, esters, and so on) from the wings and bodies of both sexes of the butterfly. Male wings secreted n-dodecane, linalool and geranylacetone as major components together with small amounts of camphene, limonene, p-cymene, 2 -phenylethanol, n-hexanal, n-decanal, isoamyl acetate, p-allylanisole, 2 -pyrrolidone and other characteristic volatiles. The overall profile of volatile compounds detected from male body was quite different from that of the wings. Male body was devoid of camphene, 2-phenyletha-nol, n-hexanal but instead contained limonene, acetoin, a sesquiterpene hydrocarbon (C15H24), methyl n-octanoate, (E,E)-hepta-2,4-dienal, and another isomer of heptadienal as principal components, of which the last four compounds were specific to the body. All these substances seem to concurrently characterize the male odor. The chemical patterns of com­ pounds found from female wings and body were essentially the same in quality as those of male wings and body, respectively, although their quantities in females were generally smaller than in males. Females, however, had a larger amount of acetamide than males. The chemical compositions of volatiles from the fore and hind wings of males were not greatly different from each other, and every component was considered to be present on all parts of the wings. This suggests that the scent-producing organs or scent-emitting pores are widely distributed on the whole wings. EA G responses of both sexes to 12 selected compounds identified from the butterfly were not strong at a dose of 1 µg, while both sexes showed relatively stronger responses to n-nonanal, methyl n-octanoate, D-limonene and linalool at a higher dose (10 [µg). Although sexual difference in EAG response was not prominent, females appeared a little more sensitive, and n-nonanal and acetoin evoked significantly higher responses from females at 1 µg.

Field observations revealed that flowers of Osmanthus fragransattract few insect species despite their strong scent and vivid coloration (yellowish orange). Floral volatiles of the plant were thus examined for suspected repellency to Pieris rapae, a potential visitor that never visits this flower. The influence of odor components on the foraging behavior of adult butterflies was assessed by two behavioral bioassays: proboscis extension reflex (PER) in response to olfactory stimuli and the frequency of visits to artificial flowers. In the PER bioassays, a binary mixture composed of a test material and 2-phenylethanol (a positive standard compound) was used, and the negative effect of test materials was appraised based on the degree of suppression caused compared with the original PER performance evoked by 2-phenylethanol alone. Isopentane extract of the flower exhibited significant deterrency in the PER test and remarkable repellency in the flower-visiting experiment, thereby suggesting the presence of a repellent(s) in the floral volatiles. Fractionation of the extract by silica gel column chromatography yielded an active fraction (based on PER performance), which, upon GC and GC-MS analyses, was found to consist of γ-decalactone, β-ionone, and linalool oxide (LO) isomers (furanosides and pyranosides) as major components together with small amounts of linalool and α-ionone. γ-Decalactone was strongly deterrent in the PER test, and β-ionone and all LO isomers were weakly deterrent, while the other compounds exhibited no deterrency. In the flower-visiting tests, γ-decalactone showed notable repellency, whereas β-ionone had no repellent effect. Among the LO isomers, at least furanosides (cis/transmixture) and cis-pyranoside were found to be weakly repellent. On the other hand, the butterfly showed strong to weak EAG responses to LO furanosides, cis-LO pyranoside, γ-decalactone, and β-ionone in decreasing order of intensity. The present results clearly indicate that the repellency of a compound is correlated with its deterrent effect on PER but not necessarily with antennal sensitivity.

Scent and coloration of corolla were examined as floral attributes responsible for preferential visiting by the cabbage butterfly, Pieris rapae, to rape flower, Brassica rapa. Floral volatile components that release the flower-visiting behavior of the butterfly were identified by chemical analyses, electroantennography (EAG), and two behavioral bioassays: proboscis extension reflex (PER) in response to odor and attraction to artificial flowers. GC and GC-MS analyses of the headspace volatiles from the flowers revealed the presence of six aromatic compounds, benzaldehyde, phenylacetaldehyde, benzyl alcohol, 2-phenylethanol, phenylacetonitrile, and indole in decreasing order of quantity. Of these, phenylacetaldehyde elicited the highest response in the PER assay. While benzyl alcohol, 2-phenylethanol, benzaldehyde, and phenylacetonitrile evoked moderate responses, the PER-eliciting activity of indole was very weak. In two-choice behavioral bioassays, artificial flowers scented with any one of these PER-active compounds attracted significantly more butterflies than control (unscented) flowers, whereas those treated with indole were almost inactive. The EAG activities of the six chemicals were not high and were about the same at a low dose (1 μg), but phenylacetaldehyde elicited a much stronger response from both sexes at higher doses (10 and 100 μg). An overall profile of EAG responses at a dose of 100 μg was analogous to that of PER performance, suggesting that floral volatiles may be involved in close-range location or recognition of flowers rather than long-range attraction. By spectroscopic and UV-photographic examinations of rape flower, the central part of the corolla was found to absorb UV rays in marked contrast to the other parts, which reflected near-UV rays (λmax= 350 nm). This indicates that the flower is endowed with a conspicuous nectar guide that is probably an important visual stimulus for attracting foraging adults of P. rapae. Consequently, the present findings strongly suggest that this elaborate pollination strategy of rape flower, characterized by its good combination of olfactory and visual attractiveness, accounts for preferential visiting by the cabbage butterfly to the flower.

Floral scent compounds of Ligustrum japonicumthat affect the foraging behavior of Pieris rapaeadults were examined by means of chemical analyses, electroantennogram (EAG) responses, and behavioral bioassays; the behavioral biossays consisted of two tests: reflex extension of proboscis (REP) in response to odor, and attraction to scented and unscented artificial flowers. More than 30 compounds, including 2-phenylethanol, benzyl alcohol, and methyl phenylacetate as the major components were identified from L. japonicumflowers. Of these, 22 compounds were tested for their effect on foraging behavior. Phenylacetaldehyde (PA), 2-phenylethanol (PE), and 6-methylhept-5-en-2-one (MHO) elicited the highest REP responses, and benzaldehyde (BA) and methyl phenylacetate (MPA) evoked intermediate REP responses. EAG responses were not necessarily correlated with REP activities; the three high-REP compounds gave only moderate EAG responses, whereas two other compounds (ethyl phenylacetate and 2-phenylethyl acetate) that released high EAG responses showed low REP activities. In two-choice behavioral bioassays, flower models scented with any one of these high-REP compounds attracted significantly more adults, while compounds with low REP activities exhibited weak or no appreciable attractiveness. This suggests that the REP responsiveness closely reflects the attractiveness of a compound and could be an effective measure in elucidating which chemical attractants are involved in flower-visiting. A synthetic blend of five floral chemicals (PA, PE, MHO, BA, and MPA) displayed an attractiveness that was comparable to that of the floral extract and was more effective in attractiveness than the compounds tested singly. Consequently, it is highly likely that the flower-visiting by P. rapaeto L. japonicumis mediated largely by floral scent chemicals and that a synergistic effect of the five floral components would be most responsible for attraction of the butterfly to this flower. The present results also strongly suggest that specific floral volatiles may facilitate close-range flower location by P. rapae, could serve in part as a cue for recognizing food sources, and also be profoundly implicated in flower preference.

A giant danaid butterfly, Idea leuconoe, specializes on apocynaceous plants such as Parsonsia laevigata, which has been reported to contain pyrrolizidine alkaloids. Females of I. leuconoedeposited eggs in response to methanolic extract of P. laevigata, and subsequent bioassay-guided fractionation of the extract revealed that phytochemicals crucial for host recognition by ovipositing females are Parsonsia-specific macrocyclic pyrrolizidine alkaloids including parsonsianine, parsonsianidine, and 17-methylparsonsianidine. Parsonine, another P. laevigatapyrrolizidine component with a keto-dihydropyrrolizine moiety that is closely related in structure to male pheromones of the butterfly, and several nonhost pyrrolizidine alkaloids were entirely inactive. We interpret these data as strong evidence for an ancestral association through herbivory between danaid butterflies and pyrrolizidine alkaloids.

Investigations were carried out on the origin of osmeterial secretions exuded by fourth instar larvae of Papilio helenusand P. protenorthat had been reported to secrete a variety of terpenic compounds. Variations in the chemical composition of the secretion induced by dietary and/or genetic factors were quantitative rather than qualitative in both species. Overall pattern of the chemical constituents was found to be highly species-specific and substantially invariable in a given species. Several sesquiterpene hydrocarbons secreted by the larvae were not present in detectable amounts in the leaves of the host plant, Fagara ailantoides, suggesting that the sesquiterpenes were biosynthesized by these larvae. Deuterium was efficiently incorporated in vivointo sesquiterpene hydrocarbons in the secretion, (E)-β- farncsene, β-caryophyllene, germacrene-A and germacrene-B, by topical application of deuteriumlabelled acetic acid to everted osmeteria, while similar treatment with deuterium oxide resulted in much lower incorporation of deuterium. These results provide evidence for de novabiosynthesis of sesquiterpene hydrocarbons in young Papiliolarvae.

A series of new amphoteric surfactants, sodium salts of 2-(N-alkyl-N-methylamino)ethanephosphates (alkyl: n-dodecyl, n-tetradecyl and n-hexadecyl) were prepared by reacting alkylbromides with N-methylaminoethanol, followed by addition of phosphoric acid groups and neutralization with sodium hydroxide. The structures of these compounds were confirmed by spectroscopy and elemental analysis. Physical properties such as Krafft point, isoelectric point, critical micelle concentration, occupation area of molecule at surface, foaming power and the effect of pH on surface activity were evaluated. These surfactants were found to exhibit zwitterionic characteristics in the pH range from approximately 5 to 9 and demonstrated good surface-active properties over a wide pH range (pH 4~10). Large occupation areas of the molecule at a surface in comparison with sodium dodecyl sulfate was noted as a characteristic feature of these surfactants.

We studied the chemical basis for the differential acceptance of a rutaceous plant.Phellodendron amurense, by ovipositing females of two sympatricPapilio butterflies,P. protenor andP. xuthus, that have a very similar host range.P. amurense, on which larvae of both species perform well, was rejected byP. protenor females but was marginally accepted byP. xuthus, even though water-soluble fraction of this plant elicited significant ovipositional responses from the two species. A prenylated dihydroflavonol glucoside, 3,5,7,4′-tetrahydroxy-8-(3-methylbut-2-enyl)flavanone-7-O-β-glucoside (phellamurin), was identified as a dominant active substance that deters oviposition.P. protenor responded highly sensitively to phellamurin, whereasP. xuthus was less susceptible and was affected conspicuously only at higher concentrations than that found in living plants, thereby accounting for their differential responses toP. amurense. InP. protenor, the deterrent effect of phellamurin was considered to outweigh the activity of coexisting stimulant(s) at the concentrations actually present in the foliage, resulting in avoidance of this plant. The phellamurin content in the foliage amounted to as much as 1.8% of the fresh weight, which is far higher than the average levels of flavonoids present in other major host plants ofPapilio. The dose-response experiments demonstrated that unacceptability ofP. amurense forP. protenor was attributable largely to such a high concentration of phellamurin. These results appear to provide information on possible coevolutionary interactions between herbivores and plants and also on the potential for shifts in host affiliation.

A feeding deterrent against larvae of a papilionid butterfly,Luehdorfia puziloi (Parnassiinae), a specialist onAsiasarum plants (Aristolochiaceae), was isolated from another aristolochiaceous plant,Heterotropa aspera. Antifeedant activity was exhibited by then-hexane-soluble fraction that proved to contain at least two active components. One of the deterrents was identified as a neolignan compound, asatone. The concentration of asatone inH. aspera was estimated at approximately 225 ppm, and larval feeding ofL. puziloi was significantly deterred at concentrations over 90 ppm. By contrast, asatone was not detectable (< 1 ppm, if any) in its host plant,Asiasarum sieboldii.

Volatile components of the larval osmeterial secretion ofParnassius glacialis (Parnassiinae, Parnassiini) consisted of isobutyric acid, 2-methylbutyric acid, and their methyl esters. In contrast, the osmeterial exudate ofSericinus montela (Parnassiinae, Zerynthiini) was characterized as monoterpene hydrocarbons comprisingβ-myrcene (Major),α-pinene, sabinene, limonene, andβ-phellandrene, whereas that ofPachliopta aristolochiae (Papilioninae, Troidini) was composed of numerous sesquiterpene hydrocarbons, includingα-himachalene,α-amorphene, and germacrene-A, and a few oxygenated sesquiterpenoids. In these three species, the chemical nature of the secretions of the last and the penultimate instars was essentially of similar quality, suggesting that the three genera,Parnassius, Sericinus, andPachliopta, are assigned to homogeneous types.

Identification of chemical compounds responsible for the oviposition behavior in a Rutaceae feeder,Papilio protenor demetrius, was undertaken with the epicarp of sour orange (Citrus natsudaidai) which exhibited potent stimulatory activity as did its leaves for egg-laying by the females. The stimulants were present in the hydrosoluble fraction, and the kairomonal activity displayed by the peel was regarded as originating from the synergistic effect of the total chemical complex. One of the active compounds was identified as a flavanone glycoside, naringin (naringenin-7ß-neohesperidoside), which, although showing no appreciable effectiveness when bioassayed alone, elicited positive response at the concentration of 0.2% either when admixed with other unidentified components or provided the females had been conditioned with them in advance. Another flavanone glycoside, hesperidin (hesperetin-7ß-rutinoside) that was contained in a trace amount in the peel also had a positive effect comparable to that of naringin under similar conditions, while their corresponding aglycones were less active or inactive. In contrast, a flavone glycoside, rhoifolin, coexisting in the peel, and some other flavones and flavonols tested as possible candidates for oviposition stimulants were all found entirely ineffective.

Host-plant chemicals stimulating oviposition by a Leguminosae-feeding pierid butterflyColias erate poliographyswere isolated and identified from one of its primary host plants, white clover (Trifolium repens). Females readily deposited eggs in response to methanolic extracts of the plant, and subsequent partition of the extracts with organic solvents revealed that chemical constituents critical for host recognition reside in the water-soluble fraction. Further fractionation of the hydrosoluble fraction by column chromatography led to the separation of an active fraction and two cyanoglucosides, linamarin and lotaustralin. Conspicuous oviposition response was evoked by unidentified polar compound(s), while these cyanoglucosides exerted no stimulatory activity by themselves. However, ovipositing females preferred samples containing either of the two cyanoglucosides. In dual-choice bioassays, significantly more eggs were laid on samples admixed with the cyanoglucosides, suggesting that the cyanoglucosides serve as synergistic oviposition stimulants and could play an important role in host selection.

The ovipositional response of a Rutaceae-feeding papilionid butterfly,Papilio protenor, toCitrus host plants was evoked by the synergistic action ofl-(-)-stachydrine,d-(-)-quinic acid, (-)-synephrine, andl-(-)-proline that characterize the chemical compositions of the leaves and epicarp ofCitrus plants (C. natsudaidai andC. unshiu). The stimulatory activity of their mixture was enhanced by the addition of flavanone glycosides, naringin and hesperidin, which coexist in these plants and have previously been demonstrated to serve as oviposition stimulants. However, sugars such as sucrose, glucose, and inositols, which abound in plant tissues, exerted no effect on egg-laying by the females. On the other hand, chlorogenic acid present in the leaves of another host plant,Fagara ailanthoides, was found to act as an excellent synergist. However, there existed significant qualitative dissimilarities between the chemical compositions of the leaves ofC. unshiu andF. ailanthoides. This strongly suggests thatP. protenor is likely to utilize different categories of compounds as chemical cues in recognizing each plant as a host.

The larval osmeterial secretions of sixPapilio species examined displayed a remarkable qualitative change at the fourth larval ecdysis. The secretions of 4th (penultimate) instar larvae ofP. machaon, P. memnon, P. helenus, P. bianor, andP. maackii principally comprised mono- and/or sesquiterpenoids. The compounds identified from these species included a-pinene, sabinene, ß-myrcene, limonene, ß-phellandrene, (Z)-ß-ocimene, (E)-ß-ocimene, ß-elemene, ß-caryophyllene, (E)-ß-farnesene, ß-selinene, (E,E)-a-farnesene, germacrene-A, germacrene-B, caryophyllene oxide, methyl 3-hydroxy-n-butyrate, and acetic acid. In contrast, the secretion of 4th larval instar ofP. xuthus, although containing similar terpenic compounds, was accompanied by large amounts of aliphatic acids and their esters: isobutyric acid, 2-methylbutyric acid, methyl isobutyrate and methyl 2-methylbutyrate. On the other hand, the osmeterial secretions of 5th (last) instar larvae varied little in quality among the six species, and the identified compounds consisted of isobutyric acid, 2-methylbutyric acid, methyl isobutyrate, ethyl isobutyrate, methyl 2-methylbutyrate, ethyl 2-methylbutyrate, and isovaleric acid, the last of which was specific toP. bianor andP. maackii. The chemical alteration of osmeterial exudate synchronized at the final larval ecdysis with the larval morphological change (particularly in body coloration) that appears to be of defensive significance against predators.

Benzaldehyde, phenylacetaldehyde (major component), 2-phenylpropenal,n-heptanal, 6-methylhept-5-en-2-one, and linalool were identified as compounds responsible for the male scent ofAtrophaneura alcinous alcinous. These substances were present predominantly in the wings, and the quantity of them was largest at the inner margin of the hind wing. Female wings also contained some of them in much smaller (except a few components) amounts. The relative proportion of each component exhibited manifests sexual differences.

Ethyl, n-dodecyl, and n-hexadecyl esters of urocanic acid (4-imidazoleacrylic acid) were prepared from 4-imidazolecarboxaldehyde in satisfactory yields viathe Wittig reaction.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.