Constraint of Feeding by Chronic Ingestion of 1,8-Cineole in the Brushtail Possum (Trichosurus vulpecula)

Eucalyptus leaf-eating marsupials such as the brushtail possum (Trichosurus vulpecula) ingest large amounts of terpenes, especially 1,8-cineole (cineole)--the major component of many eucalyptus oils. Brushtail possums were acclimated to a non-Eucalyptus diet with increasing concentrations of cineole (0.5-4.0% wet weight) added over 18 d. We measured food and cineole consumption and urinary metabolites of cineole. Food intake decreased with cineole content, indicating that it was constrained by the maximum tolerable intake of cineole that was 3.8 +/- 0.2 g kg(-1) or 5.2 +/- 0.3 g kg(-0.75) (mean +/- SE, N = 6). The pattern of metabolites was similar at all cineole intakes (56% hydroxycineolic acids, 27% cineolic acids, 13% hydroxycineoles, and 4% dihydroxycineoles). In another experiment, possums maintained on artificial diet were abruptly presented with 4% cineole for 5 d. Food intake fell by 45 +/- 6% (mean +/- SE, N = 6) and mean cineole intake was 2.9 +/- 0.3 g kg(-1). There was evidence of induction of secondary oxidative pathways, as hydroxycineoles were the major metabolites (48% total) on the first day, but rapidly dropped to 15% on subsequent days as the acid metabolites increased. These findings indicate that ingestion of cineole is not constrained by selective saturation of individual enzymes involved in its multiple pathways of oxidation, but rather the total detoxification capacity appears to limit feeding on a cineole diet.     

Triacylglycerol Estolides,a New Class of Mammalian Lipids,in the Paracloacal Gland of the Brushtail Possum (Trichosurus vulpecula)

The paracloacal glands are the most prevalent scent glands in marsupials, and previous investigation of their secretions in the brushtail possum (Trichosurus vulpecula) has identified many odorous compounds together with large amounts of neutral lipids. We have examined the lipids by LC–MS, generating ammonium adducts of acylglycerols by electrospray ionisation. Chromatograms showed a complex mixture of coeluting acylglycerols, with m/z from about 404 to 1048. Plots of single [M + NH₄]⁺ ions showed three groups of lipids clearly separated by retention time. MS–MS enabled triacylglycerols and diacylglycerol ethers to be identified from neutral losses and formation of diacylglycerols and other product ions. The earliest‐eluting lipids were found to be triacylglycerol estolides, in which a fourth fatty acid forms an ester link with a hydroxy fatty acid attached to the glycerol chain. This is the first report of triacylglycerol estolides in animals. They form a complex mixture with the triacylglycerols and diacylglycerol ethers of lipids with short‐ and long‐chain fatty acids with varying degrees of unsaturation. This complexity suggests a functional role, possibly in social communication.     

Odor of the muskox

The behavior of captive male muskoxen was observed closely during their characteristic superiority display, the anatomy of the preputial region was studied in two adults and three calves, and preputial washings and preorbital gland secretion were subjected to gas chromatography and mass spectroscopy. During the superiority display, the prepuce was everted to form a pendulous tube tipped with a fringe of matted hair. Owing to the movement of the animal, the urine that dribbled from the preputial opening was liberally applied to the long guard hairs of the belly. The superiority display was almost exclusively confined to dominant males and apparently accounted for their odor. In the quiescent state, the hair seen around the preputial opening was drawn inside and formed an 8 cm-wide band on the lining of the prepuce. The preputial washings contained large amounts of benzoic acid andp-cresol. The infraorbital gland secretion contained cholesterol, benzaldehyde, and a homologous series of saturated -lactones ranging from 8 to 12 carbons. The latter compounds and the natural secretion smell similar to the human nose.     

Role of Detoxification of Plant Secondary Compounds on Diet Breadth in a Mammalian Herbivore, Trichosurus vulpecula

Theory predicts that mammalian herbivores detoxify different classes of plant secondary compounds via separate metabolic pathways and that generalist herbivores maintain broad diet breadth to avoid overloading individual detoxification pathways. We tested the hypothesis that a generalist marsupial herbivore, the common brushtail possum, Trichosurus vulpecula, can maintain a higher intake of food when allowed to select from two diets containing different profiles of secondary compounds (phenolics and terpenes) than when given access to the diets individually. Diets consisted of a fruit and vegetable mash to which was added ground leaves of either Eucalyptus melliodora or E. radiata. E. melliodora and E. radiata differ in their concentrations and types of secondary compounds. Brushtail possums include these eucalypt species as part of their natural diet. We measured food consumption and detoxification metabolites of possums on these diets. Consistent with the hypothesis, animals presented with a choice of both diets consumed more food than animals given diets singly. One of the two indicators of detoxification, acid load in urine, differed significantly between diets while the other, glucuronic acid, did not. These results provide partial support for the hypothesis that diet breadth is governed by detoxification abilities.     

Defining Sources of Coffee Plant Odor Attractive toCeratitis Capitata Flies

We evaluated attraction of released mature laboratory-cultured Mediterranean fruit flies to different sources of coffee plant odor placed in potted nonfruiting guava trees in outdoor field cages. Volatiles from crushed medium or dark red fruit ofCoffea arabica cv. arabica plants were significantly more attractive than volatiles from cut leaves or stems of such plants, volatiles from less-ripe crushedC. arabica fruit, and volatiles from crushed red fruit ofC. racemosa,C. canephora, orC. dewevari. Volatiles fromC. arabica cv. arabica crushed red fruit were equally attractive as volatiles from crushed red fruit ofC. congensis orC. arabica cv. mundo, cv. bourbon, cv. kents or cv. catura. Volatiles from as little as 2 g of crushed redC. arabica fruit (= 1 fruit) were as attractive as volatiles from 32 g of such fruit, demonstrating sensitivity of the bioassay approach used to a small amount of source material. Odor ofC. arabica red fruit refrigerated for 1–10 days after picking was significantly more attractive than odor of fresh-picked fruit, while odor of a 24-hr water extract of intact redC. arabica fruit was significantly more attractive than odor of 24-hr extracts of such fruit with methanol, methylene chloride, or hexane or 1- or 6-hr extracts with water. Extraction studies suggested that at least some of the volatiles of red coffee fruit attractive to medflies may be polar water-soluble molecules. In our final test, volatiles from crushed redC. arabica fruit trapped on Super Q and eluted with methylene chloride proved just as attractive as volatiles emanating directly from crushed fruit of the same type. Together, our findings define optimal source material and effective handling procedures of source material for future identification of volatile components of coffee fruit attractive to medflies.     

Effects of two plant secondary metabolites,cineole and gallic acid,on nightly feeding patterns of the common brushtail possum

We investigated effects of two plant secondary metabolites (PSMs), cineole and gallic acid, on the nightly feeding behavior of the common brushtail possum (Trichosurus vulpecula), a generalist folivore. We tested whether possums altered their feeding behavior in response to increasing levels of cineole, a dietary terpene. Possums were fed artificial diets containing three levels of cineole; zero (basal diet), medium (6.8% of total dry matter, DM), and high (15.3% DM). In another experiment, we introduced gallic acid, a dietary phenolic, into the diets. Possums were offered a Choice PSM diet (cineole and gallic acid diets simultaneously) or a No-Choice PSM diet (containing either cineole or gallic acid). Detoxification products of cineole and gallic acid were examined in urine to determine that different detoxification pathways were utilized in the elimination of each compound. With increasing cineole levels, possums ate less, had smaller feeding bouts, and had a lower rate of intake, but did not extend their total nightly feeding time. Possums offered the Choice PSM diet, compared with the No-Choice diets, ate more, had larger feeding bouts, and tended to increase their rate of intake. Results from the urinary analysis indicated that gallic acid and cineole were not involved in competing detoxification pathways in brushtail possums. There was also a significant sex effect: females ate more overall, ate more per feeding bout, and ate at a higher rate than males. These results indicate that PSMs not only constrain overall intake, but that possums alter their feeding behavior in response to them. Altered feeding patterns may reduce the negative influence of PSMs on intake.     

Inheritance Of Resistance to Mammalian Herbivores and of Plant Defensive Chemistry in an <Emphasis Type="Italic">Eucalyptus</Emphasis> Species

Hybridization in plants provides an opportunity to investigate the patterns of inheritance of hybrid resistance to herbivores, and of the plant mechanisms conferring this resistance such as plant secondary metabolites. We investigated how inter-race differences in resistance of Eucalyptus globulus to a generalist mammalian herbivore, Trichosurus vulpecula, are inherited in their F₁ hybrids. We assessed browsing damage of 3-year-old trees in a common environment field trial on four hybrid types of known progeny. The progeny were artificial intra-race crosses and reciprocal inter-race F₁ hybrids of two geographically distinct populations (races) of E. globulus north-eastern Tasmania and south-eastern Tasmania. Populations of trees from north-eastern Tasmania are relatively susceptible to browsing by T. vulpecula, while populations from south-eastern Tasmania are more resistant. We assessed the preferences of these trees in a series of paired feeding trials with captive animals to test the field trial results and also investigated the patterns of inheritance of plant secondary metabolites. Our results demonstrated that the phenotypic expression of resistance of the inter-race F₁ hybrids supported the additive pattern of inheritance, as these hybrids were intermediate in resistance compared to the pure parental hybrids. The expression of plant secondary metabolites in the F₁ hybrids varied among major groups of individual compounds. The most common pattern supported was dominance towards one of the parental types. Together, condensed tannins and essential oils appeared to explain the observed patterns of resistance among the four hybrid types. While both chemical groups were inherited in a dominant manner in the inter-race F₁ hybrids, the direction of dominance was opposite. Their combined concentration, however, was inherited in an additive manner, consistent with the phenotypic differences in browsing.     

Attraction of Mature Ceratitis capitata Females to 2-Heptanone, A Component of Coffee Fruit Odor

In indoor laboratory-cage and outdoor field-cage assays, we evaluated the attraction of released, protein-fed, mature Mediterranean fruit fly females to six volatile compounds emitted by attractive crushed ripe coffee fruit: 3-methyl-1-butanal, decanal, 3-methyl-1-butanol, 2-(Z)-pentenol, 2-(E)-hexenol, and 2-heptanone. Previous tests in a wind tunnel indicated that each of these six compounds was more attractive than clean air to females. In laboratory cage assays, none of the compounds elicited a response significantly greater than that to water. In field-cage assays, 2 or 4 l of 2-heptanone in 5 ml of water (but none of the other compounds at 2 or 4 l in 5 ml of water) consistently attracted protein-fed medflies at significant levels that averaged about five times greater than attraction to water alone, although about 40% less than attraction to odor of coffee fruit extract. All types of mature protein-fed females tested (laboratory-cultured virgin, laboratory-cultured mated, wild mated) in field-cage assays responded similarly to 2-heptanone, whereas same-age (9- to 11-day-old) protein-deprived females did not respond significantly to 2-heptanone. Response of protein-fed females to 2-heptanone increased progressively with increasing dose (1, 2, 4, or 8 l in 5 ml of water). Addition of 2 l of 2-heptanone or 2 l of any of the other compounds tested to 5 ml of water extract of coffee fruit did not enhance attractiveness of the extract. Relative to response to water, protein-fed females consistently exhibited a significant positive response to odor of coffee fruit extract but no significant response to odor of Nulure (a proteinaceous food attractant). Together, our findings suggest that mature protein-fed females were responding to 2-heptanone as though it were an oviposition-site stimulus rather than a feeding-site stimulus.     

Odor learning and foraging success in the parasitoid,Leptopilina heterotoma

A brief 2-hr experience with hostDrosophila larvae in artificial apple-yeast or mushroom microhabitats had three effects on the foraging behavior of femaleLeptopilina heterotoma (Hymenoptera: Eucoilidae) parasitoids under field conditions. First, experienced females released at the center of circular arrays of apple-yeast and mushroom baits were more likely to find a microhabitat over the course of a daily census than naive ones. Second, for those females that found a microhabitat, experienced ones found it faster than naive ones (i.e., experience reduced travel times). Third, females experienced with a particular microhabitat were more likely to find that micro-habitat than an alternative one. Learned preferences were retained for at least one day and possibly as many as seven. Results generally did not depend on the host species (D. melanogaster orD. simulans) with which females were given experience. Females tended to arrive at baits upwind of the point of release, suggesting that odor is involved in finding host microhabitats and, in particular, in learning to find them more effectively. The implications of these results for the application of semiochemicals in biological control are discussed briefly.     

Responses of Cambarid Crayfish to Predator Odor

The responses of individuals of four sympatric species of cambarid crayfish to the introduction of the odor of a common predator, the snapping turtle Chelydra serpentina, were recorded in the laboratory. Adult Orconectes virilis spent significantly more time in a lowered posture and reduced the frequency of nonlocomotory movements following introduction of snapping turtle odor but showed no change in behavior upon introduction of the odor of painted turtle (Chrysemys picta). Recently released young O. virilis did not respond to snapping turtle odor initially but did so after turtle odor and conspecific alarm odor had been paired. Individuals of O. propinquus did not respond to snapping turtle odor. Initial tests with O. rusticus did not yield any response to snapping turtle odor but after experience with paired turtle and alarm odor, individuals showed a decrease in nonlocomotory movements when just snapping turtle odor was introduced. Individuals of Cambarus robustus spent less time in the lowered posture, less time in their burrow, and more frequently executed nonlocomotory movements, in response to snapping turtle odor. The differences in responses to the odor of a common predator are correlated with ecological differences among the crayfish species.     

Development of Tolerance to the Dietary Plant Secondary Metabolite 1,8-cineole by the Brushtail Possum (<Emphasis Type="Italic">Trichosurus vulpecula</Emphasis>)

The common brushtail possum (Trichosurus vulpecula) is a generalist herbivore whose diet includes Eucalyptus leaves that are well defended by plant secondary metabolites (PSM) such as the terpene 1,8-cineole (cineole). We accustomed possums to a terpene-free diet, then challenged them with the addition of 2% cineole to the diet. Initially, there was a 50% reduction in total overnight food consumption associated with a marked decrease in the mass of the major feeding bout. After nine nights, however, cineole tolerance had developed as total food consumption had returned to the control amount. Compared to the control diet, the cineole diet was eaten in a larger number of smaller bouts, which were also eaten at a slower rate. The experiment was repeated with animals that had been accustomed to day-time feeding to take blood samples during feeding sessions. Feeding variables and blood concentration data for cineole were compared on the first and seventh day of the cineole diet. Although the total food consumed increased 2.5-fold after 7 days of the cineole diet, there was no increase in average blood cineole concentration, measured as the area under the concentration–time curve. This indicates that induction of liver enzymes resulted in greater pre-systemic metabolism of cineole and reduced bioavailability. The maximum tolerated blood concentration of cineole also increased, suggesting some adaptation of the central nervous system to the cineole aversive effects. This appears to be the first report in a vertebrate herbivore that consumption of a dietary PSM leads to metabolism induction and that this contributes to development of tolerance to the PSM. Overall, herbivores adapt to newly encountered dietary PSMs by immediate changes in feeding behavior followed by development of increased metabolism of PSM and probably diminished cellular responsiveness to effects.     

Spatial Arrangement of Odor Sources Modifies the Temporal Aspects of Crayfish Search Strategies

In natural habitats, animals encounter cues from multiple odor sources that may impact foraging decisions. Previous work has focused on orientation behavior to one food odor source, and does not distinguish between mechanosensory and chemosensory guidance of orientation. The present study investigated how the spatial distribution of two food cues affects crayfish orientation behavior. Crayfish, Orconectes virilis, were presented with odor sources that were separated in an artificial stream. Orientation behavior was filmed from above and digitized at a rate of 1 frame per sec. Electrochemical recordings were taken to characterize the odor plume, and an acoustic doppler velocimeter was used to characterize the hydrodynamic structure of the artificial stream. Temporal changes in odor plume structure were seen as a result of the positioning of the odor sources. Changes in the intermittency of the odor pulses as well as concentration, rise time, and slope of the pulse were observed. Time series analysis showed that the lower frequency signals of the dual odor source were higher in energy than the single 1X or single 2X sources. Crayfish altered orientation strategies when presented with different spatial arrangements of food cues. In particular, the temporal aspects of the orientation pattern were most altered by the differences in odor presentations. Crayfish responded with faster walking speeds as a function of distance to the odor source and exhibited more consistent turning angles. This correlates with temporal changes in odor structure, and indicates that the temporal pattern of odor stimulation may be driving the temporal pattern of behavior.     

Comparative Metabolism of Dietary Terpene, p-Cymene, in Generalist and Specialist Folivorous Marsupials

The urinary metabolites of the monoterpene, p-cymene, were studied in three marsupial species: a generalist herbivore, the brushtail possum (Trichosurus vulpecula), and two specialist folivores, the greater glider (Petauroides volans) and the ringtail possum (Pseudocheirus peregrinus), as well as in the laboratory rat (Rattus norvegicus). Each animal was dosed, intragastrically, with single doses of p-cymene (0.37 mmol/kg and/or 1.49 mmol/kg). Urine and feces were collected for two 24-hr periods. Quantitative analysis of urinary metabolites by extraction, gas chromatography, and mass spectrometry gave a mean recovery of 64% (range 52–74%) of the administered dose in 48 hr for the four species. No fecal metabolites were found. A species-specific pattern of metabolite excretion was evident and reflected the natural occurrence of p-cymene (and terpenes in general) in the diet. If the metabolites excreted are grouped according to the total number of oxygen atoms added (one to four), then the rat excreted metabolites encompassing all degrees of oxidation, but predominantly a monooxygenated metabolite. The brushtail possum excreted metabolites having two, three, and four oxygen atoms added. The ringtail possum and greater glider only excreted metabolites with three or four oxygen atoms. Conjugation played a significant role in the excretion of oxidized metabolites in only the brushtail possums and the rat. These findings indicate that species encountering terpenes, such as p-cymene, in their normal diet have developed efficient oxidation pathways to eliminate them. This oxidative efficiency could also reduce the necessity for subsequent conjugation of metabolites which minimizes further demands on a nutritionally limited diet.     

Ecological Example of Conditioned Flavor Aversion in Plant–Herbivore Interactions: Effect of Terpenes of Eucalyptus Leaves on Feeding by Common Ringtail and Brushtail Possums

We investigated the hypothesis that feeding deterrence of common ringtail possums (Pseudocheirus peregrinus) and common brushtail possums (Trichosurus vulpecula) by Eucalyptus terpenes (in this case 1,8-cineole) is a result of a conditioned flavor aversion (CFA), due to the association of terpenes with postingestive effects of another group of Eucalyptus toxins, the diformylphloroglucinol compounds (DFPCs). Wild-caught common ringtail and common brushtail possums showed a dose-dependent reduction in food intake when 1,8-cineole was added to the diet. However, after continued exposure over 12 days to increasing amounts of cineole in the diet, both species substantially increased their intakes of cineole relative to control animals. This indicated that the aversion to cineole was a conditioned response rather than a physiological limitation in their ability to detoxify terpenes. Subsequent exposure to a diet including both cineole and jensenone (a simple DFPC also found in Eucalyptus and considered to cause postingestive emesis) in corresponding amounts was able to recondition the dose-dependent aversion. Consequently, animals that had been given jensenone showed an aversion to cineole-rich diets that matched the behavior of animals in the control group. This supported our hypothesis that the effect of terpenes on feeding of these marsupial folivores on Eucalyptus is due to a CFA. Possums can cope with levels of terpenes in the diet that far exceed those occurring naturally. The role of terpenes in marsupial folivore–Eucalyptus interactions appears to be to act as a cue to levels of toxic DFPCs in the leaves, rather than acting as toxins in their own right.     

Changing Oviposition Preferences of the Desert Locust, Schistocerca gregaria, Suggest a Strong Species Predisposition for Gregarization

Field surveys at five sites within desert locust breeding habitats around Port Sudan during three successive seasons indicated that early in the rainy season the incoming solitary females oviposited predominantly in the vicinity of Heliotropium spp. (66%) and millet (32%) seedlings. Solitary nymphs also preferred to feed on these plants. Follow-up cage experiments were conducted in the field in which solitary and gregarious female locusts were presented with choices of selected desert plants and egg pods. When presented with bulrush millet, Heliotropium spp., Zygophyllum simplex, and untreated moistened sand, solitary females oviposited adjacent to the first two plants (40% and 60%, respectively). However, when offered a choice of either or both of these plants together with egg pods derived from gregarious and/or solitary insects, solitary females showed a significantly higher preference for ovipositing near gregaria egg pods than near the plants, with solitaria egg pods eliciting the least response. In contrast with solitary females and in the absence of gregaria egg pods, gregarious females preferred to oviposit in untreated moist (control) sand (74–77%) away from the plants (6–14%) or solitaria egg pods (4%). However, when present, gregaria egg pods elicited significantly more oviposition. These and previous results indicate a hierarchy of phase-dependent oviposition preferences in the desert locust and are interpreted in terms of a strong propensity of the species to exploit opportunities under appropriate conditions to facilitate congregation and the gregarization of the progeny.     

Laboratory Evaluation of Predator Odors for Eliciting an Avoidance Response in Roof Rats (Rattus rattus)

We evaluated eight synthetic predator odors and mongoose (Herpestes auropunctatus) feces for eliciting avoidance responses and/or reduced feeding by wild captured Hawaiian roof rats (Rattus rattus). In a bioassay arena, we recorded: (1) time until each rat entered the arena, (2) time elapsed until first eating bout, (3) time spent in each half of the arena, (4) number of eating bouts, and (5) consumption. Rats displayed a response to the predator odors in terms of increased elapsed time before initial arena entry and initial eating bout, a lower number of eating bouts, and less food consumption than in the respective control groups. The odor that produced the greatest differences in response relative to the control group was 3,3-dimethyl-1,2-dithiolane [from red fox (Vulpes vulpes) feces and mustelid anal scent gland]. Mongoose fecal odor produced different responses in four of the five variables measured while (E,Z)-2,4,5-trimethyl-³-thiazoIine (red fox feces) and 4-mercapto-4-methylpentan-2-one (red fox urine and feces) odors were different from the control group in three of the five variables measured. These laboratory responses suggest that wild Hawaiian roof rats avoid predator odors.     

Floral Odor Variation in Two Heterostylous Species of <Emphasis Type="Italic">Primula</Emphasis>

Floral traits such as odor, color, and morphology are important pollinator attractants. Variation in floral traits may influence floral constancy, the tendency of pollinating insects to visit flowers of only one type. We investigated for the first time variation in odor between floral morphs in heterostylous species. We analyzed inter- and intraspecific odor variation in the pin and thrum floral morphs of sympatric Primula elatior and P. farinosa (Primulaceae). Floral volatiles were sampled with headspace sorption. Quantitative analysis and chemical identification were performed by gas chromatography coupled to mass spectrometry. The species produced different floral bouquets. P. elatior emitted mostly limonene with small amounts of -pinene, myrcene, and sabinene. P. farinosa produced benzaldehyde, 4-oxoisophorone (2,6,6-trimethyl-2-cyclohexene-1,4-dione), benzyl alcohol, and benzyl acetate. These interspecific differences may play a role in promoting floral constancy and maintaining species integrity. Conversely, no differences were detected between the scents of pin and thrum morphs within each species. Heterostyly relies on pollinators visiting both floral morphs. There may be a stabilizing selection against divergences in traits that may cause pollinators to develop floral constancy to only one of the floral morphs.This revised PDF version was published online in May 2005 with added Published Online dates.     

Responses of the Pollinating Wasp Ceratosolen solmsi marchali to Odor Variation Between Two Floral Stages of Ficus hispida

During development of figs on Ficus hispida, only the female floral stage is receptive to its pollinator Ceratosolen solmsi marchali. After this stage, the quantity of fig odor decreases. The effects of F. hispida volatiles from receptive figs (figs at the female floral stage, when they are pollinated) and interfloral figs (between the female floral and male floral stages) on their pollinator were studied, together with responses to compounds present in the odor. Odors emitted by both receptive and interfloral figs were attractive to the pollinator. However, wasps preferred the odor of receptive figs to that of interfloral figs even though the quantity of interfloral volatiles increased. Three monoterpenes that included linalool (major constitutent) and two minor compounds limonene and β-pinene from the receptive fig volatiles were used to test the pollinator responses. The levoisomer and racemic mixtures of linalool were attractive to the pollinator at high doses, but the dextroisomer was neutral. (±)-Limonene and (−)-β-pinene at high doses were even less attractive to the pollinator than clean air and were neutral at low doses, while (R)-(+)-, (S)-(−)-limonene were neutral at all doses. In blend tests, all four mixtures of (±)-linalool or (S)-(−)-linalool combined with (±)-limonene or (−)-β-pinene attracted C. solmsi marchali when administered at high doses. (R)-(+)-linalool and (−)-β-pinene enhanced the attractiveness of (S)-(−)-linalool to the pollinator, while enantiomers of limonene did not. These results suggest that both quality and quantity of fig volatiles regulate C. solmsi marchali response and that quality is the main host-finding and floral stage-distinguishing cue for the pollinator. Synergistic effects of some compounds may play a role in enhancing attractiveness of the active compounds.     

Rapid Absorption of Dietary 1,8-Cineole Results in Critical Blood Concentration of Cineole and Immediate Cessation of Eating in the Common Brushtail Possum (<Emphasis Type="Italic">Trichosurus vulpecula</Emphasis>)

The blood concentration of 1,8-cineole and its metabolites was measured in six male brushtail possums while they voluntarily fed on diets laced with varying concentrations of cineole for 3 d. On the third day, blood samples were collected during and after each bout of feeding for 3 hr. Blood cineole was measured by using headspace solid-phase microextraction (SPME), while cineole metabolites were measured by liquid–liquid extraction followed by gas chromatography-mass spectroscopy. Feeding patterns were measured by continual recording of residual food weight and time. Cineole absorption was rapid, resulting in a peak blood concentration at the end of each feeding bout. The blood concentration of cineole did not exceed a critical value (51.8 ± 14.1 μmol/l) regardless of the concentration in the diet. Food and, therefore, cineole intake was regulated. The amount of food ingested in the first feeding bout decreased from 236 ± 52 g on the control diet to 36 ± 20 g on the 4% cineole diet. The amount of cineole ingested in the first bout (1.18 ± 1.10 g) was the same regardless of the dietary concentration and was controlled by the size of the meal. Total food eaten during the 7-hr feeding session decreased by 64% from 368 ± 94 g (control diet) to 131 ± 52 g (4% diet). Total cineole intake increased from 2.47 ± 0.60 g (1% diet) to 5.05 ± 2.41 g (4% diet). Cineole metabolites accumulated throughout the sampling period and were generally still rising at the end of blood sampling period. Blood levels of metabolites were at least 10-fold higher than cineole levels. The immediate control of feeding seems to be regulated by blood levels of cineole, whereas metabolites are likely to be more important in regulating the chronic ingestion of cineole.     

Odor of a papilionid butterfly

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.