Showing papers in "Journal of Chemical Ecology in 1977"
TL;DR: The identification of (Z)-9-tetradecenyl acetate, in addition to the other 3 components reported previously, is the first report of a 4-component pheromone system in moths.
Abstract: MaleArchips argyrospilus (Walker) were maximally attracted to a 60∶40∶4∶200 admixture of (Z)-11-tetradecenyl, (E)-11-tetradecenyl, (Z)-9-tetradecenyl and dodecyl acetates. The identification of (Z)-9-tetradecenyl acetate, in addition to the other 3 components reported previously, is the first report of a 4-component pheromone system in moths.Archips mortuanus Kearfoot, a sibling species, was maximally attracted to a blend of the same components, but in a 90∶10∶1 mix of the tetradecenyl acetates. Among a number of tortricine moths that co-occur on apples and other hosts in New York, British Columbia, and elsewhere, differences in diel rhythms of attraction and seasonal distribution are insufficient to maintain reproductive isolation. Although the attractant systems of these species often possess components in common, males are maximally attracted to a speciesspecific blend. In tortricine moths attraction specificity appears to be a paramount mechanism for species partitioning.
107 citations
TL;DR: The data support the hypothesis that there is a synergistic phytotoxic effect whenp-coumaric and ferulic acids are found together and equimolar mixtures of both acids showed greater reduction in sorghum seed germination, shoot elongation, and total seedling growth than eitherphytotoxin caused when alone.
Abstract: The data support the hypothesis that there is a synergistic phytotoxic effect whenp-coumaric and ferulic acids are found together. Equimolar mixtures of both acids showed greater reduction in sorghum seed germination, shoot elongation, and total seedling growth than either phytotoxin caused when alone. Repeated experiments showed mixtures containing 5×10−3 Mp-coumaric and 5×10−3 M ferulic acids reduced germination to 34% of controls after 24 hr and 59% by 48 hr. The same concentration of either phenol-treated seeds alone showed 69 and 92% germination at comparable times. The phytotoxic action of the combination approximated the inhibitory effect on germination of 10−2 M ferulic acid and was a greater reduction than caused by 10−2 Mp-coumaric treatments. Sorghum seedling growth was more sensitive than germination, with an equimolar mixture of 2.5×10−4 Mp-coumaric and 2.5×10−4 M ferulic acids reducing seedling dry weight significantly below weights of seedlings treated separately with 2.5×10−4 Mp-coumaric or ferulic acids. Further dilutions showed a 1.25×10−4 M concentration of either phenol was stimulatory to seedling growth, whereas a mixture of these two produced inhibition.
100 citations
TL;DR: Host finding by the fruit fly parasitoid Biosteres (Opius)longicaudatus Ashmead was found to involve attraction to fermentation products emanating from rotting fruit, a probable site for location of host larvae.
Abstract: Host finding by the fruit fly parasitoidBiosteres (Opius)longicaudatus Ashmead was found to involve attraction to fermentation products emanating from rotting fruit, a probable site for location of host larvae. Bioassays conducted in the greenhouse with all saturated 1-, 2-, and 3-carbon primary alcohols, aldehydes, and organic acids indicated that acetaldehyde was the most active agent followed by ethanol and acetic acid. Rotting fruit was attractive irrespective of the presence of host larvae, and attraction was attributed to fungal fermentation products rather than to kairomones from host larvae.
97 citations
TL;DR: Although the alarm response is likely an antipredator device, conclusive evidence for its effectiveness in reducing predation is lacking, and the apparent balance between feeding attraction to less related species and alarm response to more related species was further examined by manipulating the snails' diet.
Abstract: Nassarius obsoletus, N vibex, andN trivittatus were exposed to juices of conspecifics and taxonomically and ecologically related gastropod species Conspecific juices caused the strongest alarm responses, while those from taxonomically related species (congeners) induced less pronounced responses Juices from nonrelated species induced no alarm response with one notable exception, the strong alarm response ofN trivittatus toUrosalpinx cinerea juices Nonrelated gastropod species induced stronger feeding responses than more closely related species The strongest feeding responses, however, were induced by juices from nongastropod mollusks The apparent balance between feeding attraction to less related species and alarm response to more related species was further examined by manipulating the snails' diet Starvation resulted in a great reduction of conspecific alarm responsiveness Following the resumption of feeding, the original responsiveness was again observed Although the alarm response is likely an antipredator device, conclusive evidence for its effectiveness in reducing predation is lacking One of the predators ofNassarius obsoletus which may be responsible for maintenance of an alarm response is the green crab,Carcinus maenas
87 citations
TL;DR: It is argued that Nassarius obsoletus may have developed an alarm response to an existing nonspecific substance rather than a true alarm pheromone, and preliminary chemical analysis indicates that the substance is water soluble, heat stable, and of high apparent molecular weight.
Abstract: The gastropod snailNassarius obsoletus shows a dramatic self-burial response to the presence of crushed conspecifics. After it was shown that this burial alarm response could be reliably replicated in laboratory tests, a further characterization of the alarm substance was undertaken. Dilution experiments showed a very high response threshold resulting in a short effective radius of the substance in agreement with earlier field reports. Longevity experiments showed that the substance had lost some activity after 16 hr standing over marsh mud in sea water at room temperature; it became inactive after 24 hr. Superthreshold concentration in sea water was not necessary to keep the snails buried: Mud apparently provides an adsorption surface which can remain a stimulus source for previously unalarmed snails, and snails tend to remain buried after a short exposure to alarm substance, even when given a fresh environment. The substance is present in the snail's blood and tissues and is passively released. A potential natural predator capable of such release isCarcinus maenas, the green crab. Predator odor alone did not cause burial alarm responses. Preliminary chemical analysis indicates that the substance is water soluble, heat stable, and of high apparent molecular weight (over 100,000). A comparison with fish alarm substance and response is made in a discussion of the possible evolution of chemically triggered alarm responses. It is argued thatN. obsoletus may have developed an alarm response to an existing nonspecific substance rather than a true alarm pheromone.
84 citations
TL;DR: An attractant compound was isolated from frass produced by Trypodendron lineatum female beetles boring in Douglas fir and the proposed structure is one of two isomeric tricyclic acetals, to which the trivial name lineatin is assigned.
Abstract: An attractant compound was isolated from frass produced byTrypodendron lineatum female beetles boring in Douglas fir. The proposed structure is one of two isomeric tricyclic acetals, to which the trivial name lineatin is assigned.
76 citations
TL;DR: Evidence is presented that demonstrates the presence of kairomones for larvae of Chrysopa carnea Stephens in materials associated with egg deposition by female Heliothis zea (Boddie), involved in prey finding and/or acceptance.
Abstract: Evidence is presented that demonstrates the presence of kairomones for larvae ofChrysopa carnea Stephens in materials associated with egg deposition by femaleHeliothis zea (Boddie). These kairomones are involved in prey finding and/or acceptance.
73 citations
TL;DR: The timing of their acceptance of juvenile foliage indicates the high levels of adaptation by these insects to allow oviposition for the on-coming adults and acceptable needles for the next generation of larvae.
Abstract: Two species of pine sawflies,Neodiprion rugifrons Midd. andN. swainei Midd., feed only on matured foliage of jack pine,Pinus banksiana Lamb., and leave juvenile or current-season foliage intact. This unique form of adaptation was studied from the viewpoint of the chemical ecology of this insect-host plant relationship. It was first determined that the differential larval feeding behavior reflects the presence of feeding deterrents. Two major biologically active substances were isolated and identified as 13-keto-8(14)-podocarpen-18-oic acid and dehydroabietic acid. These account for 63.5% and 24.6% of the total deterrency, respectively. The content of the former substance in current-year foliage decreases, as the foliage begins to mature, to the levels that become acceptable toN. swainei by August (60 days old) and to the second generationN. rugifrons by September (90 days old). The timing of their acceptance of juvenile foliage indicates the high levels of adaptation by these insects to allow oviposition for the on-coming adults and acceptable needles for the next generation of larvae. The level of dehydroabietic acid, on the other hand, does not change appreciably during the same time period: this indicates that the component does not play a significant role in the mechanism of differentiating juvenile from matured foliage by the sawfly larvae.
63 citations
Abstract: The highly odorous metabolites isopropylmethoxypyrazine, methylisoborneol, and geosmin were identified from aStreptomyces sp. Their role in the odor pollution of water is discussed. 2-Isopropyl-3-methoxypyrazine has not been reported previously from actinomycetes.
59 citations
TL;DR: Analyses of the defensive secretions of 17 species of polydesmoid millipedes show that other chemicals besides HCN and benzaldehyde are liberated during cyanogenesis, providing an initial chemotaxonomic basis for distinguishing between various polydesMoid taxa.
Abstract: Analyses of the defensive secretions of 17 species of polydesmoid millipedes show that other chemicals besides HCN and benzaldehyde are liberated during cyanogenesis. Several members of the families Polydesmidae, Paradoxosomatidae, and Euryuridae are shown to secrete both phenol and guaiacol, with one paradoxosomatid also producing ethyl benzoate and benzoic acid. Also, members of the family Xystodesmidae commonly produce the three following compounds: benozoic acid, mandelonitrile benzoate, and benzoyl cyanide. Benzoyl cyanide has not been found previously as a natural product. The defensive role of these additional natural products as antipredator and antibiotic agents is discussed. For certain predators benzoyl cyanide in particular seems to possess anaesthetic properties. Our studies provide an initial chemotaxonomic basis for distinguishing between various polydesmoid taxa.
57 citations
TL;DR: It is concluded that neral and/or geranial are components of the sex pheromone system of this species.
Abstract: A laboratory investigation of theItoplectis conquisitor sex pheromone was initiated to elucidate the structure(s) of the active component(s) of the system. Functional group tests performed on crude virgin female extract classified the pheromone as unsaturated aldehyde(s) and/or ketone(s). Isolation of active fractions by gas-liquid chromatography (GLC) suggested the existence of a multicomponent pheromone system. Analysis by gas chromatography-mass spectrometry indicated the presence of saturated and unsaturated aldehydes including neral and geranial. When mixtures of neral and geranial were bioassayed independently and in combination with other active GLC fractions, they elicited male sexual activity of intensity comparable to that released by the GLC fraction (DEGS E) from which they were isolated. The authors conclude that neral and/or geranial are components of the sex pheromone system of this species.
TL;DR: The two major yeasts isolated from the southern pine beetle,Dendroctonus frontalis Zimmerman, areHansenula holstii Wickerham andPichia pinus (Hoist) Phaff; a third yeast,P. bovis van Uden et al. as discussed by the authors, has been isolated far less frequently.
Abstract: The two major yeasts isolated from the southern pine beetle,Dendroctonus frontalis Zimmerman, areHansenula holstii Wickerham andPichia pinus (Hoist) Phaff; a third yeast,P. bovis van Uden et do Carmo-Sousa, has been isolated far less frequently. The main volatile metabolites produced by these yeasts are isoamyl alcohol, isoamyl acetate, 2-phenylethanol, and 2-phenylethyl acetate.We have found that certain of these compounds, particularly the esters, can greatly, enhance the attractiveness of a mixture of frontalin:trans-verbenol: turpentine (1:1:12), at certain limiting concentrations, to walking beetles in a laboratory bioassay.
TL;DR: Although all the major constituents of the cuticular lipid from mature females were hydrocarbons, 27% of the lipid washed from 5-day-old males was a nonhydrocarbon material that was represented by a single GLC peak and was identified as heneicosan-8-ol acetate.
Abstract: Chromatograms of the cuticular lipids washed from recently emerged female and maleFannia canicularis (L.) flies were nearly identical, but by the time the flies were 5 days old, the cuticular components of the two sexes differed considerably. A monoolefin which constituted 66% of the cuticular lipid from 5-day-old females stimulated a copulatory response from males and was identified as (Z)-9-pentacosene. The cuticular lipid of the same age males contained only 1% of this compound. Although all the major constituents of the cuticular lipid from mature females were hydrocarbons, 27% of the lipid washed from 5-day-old males was a nonhydrocarbon material that was represented by a single GLC peak. This material was identified as heneicosan-8-ol acetate.
TL;DR: In this paper, a chiral shift reagent of enantiomer compositions of several bark beetle pheromone components, which are bicyclic ketals, was used for the determination.
Abstract: Details are given for the determination by a chiral shift reagent of enantiomer compositions of several bark beetle pheromone components, which are bicyclic ketals. The procedure was carried out on three samples in the range of 200 micrograms. For one sample, the determination was achieved at the level of 5 micrograms.
TL;DR: Bioassays and analysis of extracts demonstrated that compounds 1 and 2 are produced by virgin females and 3 is host-produced, and cessation of the production of 1 is coincident with diminished attractiveness of females after they have been joined by males.
Abstract: The three components of theScolytus Multistriatus aggregation attractant-4-methyl-3-heptanol (1), α-multistriatin (2), and α-cubebene (3)-were collected from beetles and elm wood by aeration, solvent extraction of host tissue, or solvent extraction of beetles and beetle parts. Bioassays and analysis of extracts demonstrated that (a) compounds 1 and 2 are produced by virgin females and 3 is host-produced, (b) cessation of the production of 1 is coincident with diminished attractiveness of females after they have been joined by males, (c) the release of 3 from elm wood is augmented by attacking beetles, and (d) the level of 3 is related to the condition of the wood, and fungal growth (particularlyceratocystis ulmi) may lead to increased levels of 3. Compound 1 was concentrated in the upper abdominal area and 2 in the abdomen tips, but neither component was in the hindgut. A gland opening through the vaginal palpi (a pair of sclerotized conical structures) was circumstantially associated with the release of 2. Compounds 1, 2, and 3 are regulatory agents that contribute to the initiation and maintenance of the beetle-elm-microorganism biosystem.
TL;DR: The colonization pattern of O. fasciatus on species ofAsclepias in north central California suggests that this species does not maximize its opportunities to sequester large quantities of cardenolides from potential hosts, and the emetic potential of lygaeids in California to vertebrate predators is briefly discussed.
Abstract: A colorimetric assay was used to quantify the amount of cardenolides in the lygaeid bugsOncopeltus fasciatus andLygaeus kalmii kalmii and their milkweed host plants (Asclepias spp.) in central California. The cardenolide content of individual insects, determined in microgram equivalents of digitoxin, varied from zero to over 300 μg per insect. Sources of variation of cardenolide content in the insects include interspecific and intraspecific differences in the content of the host plant species and also differences in the content of plant organs on which insects were feeding. This last source of variability may explain temporal variation in the cardenolide content of the insects. Adults ofO. fasciatus, which migrate into California in the late spring and early summer, and adults ofL. k. kalmii, which emerge from winter hibernacula in the early spring, contained small to immeasureable amounts of cardenolides. The colonization pattern ofO. fasciatus on species ofAsclepias in north central California suggests that this species does not maximize its opportunities to sequester large quantities of cardenolides from potential hosts. The emetic potential of lygaeids in California to vertebrate predators is briefly discussed.
TL;DR: It is concluded that H. courbaril leaf resins possess toxic and feeding-deterrent properties which make them effective as an herbivore defense.
Abstract: The hypothesis that leaf resin ofHymenaea courbaril (Leguminosae) functions as a defence against herbivory was tested in a series of experiments with the generalist herbivore, beet armyworm (Spodoptera exigua Hubn). Pure leaf resin obtained by steam distillation was incorporated into an artificial diet at 0.0%, 0.16%, 0.50%, and 1.60% (dry weight) in one experiment and 0.0%, 1.0%, and 3.2% (dry weight) in a second experiment;S. exigua larvae were reared on these diets. In four palatability experiments the amount of leaf area eaten was compared between pairs of different leaf material. Mortality due to viral infection of larvae in the first feeding experiment showed a dose-response to leaf resin concentration. In the second experiment larvae showed a dose-response in the reduction of pupal weight and delay of time to pupation. These are interpreted as a dose-related stress onS. exigua which occurs with increased resin concentration in the diet. In the palatability tests,S. exigua strongly preferred untreated to resintreated bean leaf disks, bean disks toH. courbaril immature leaf disks,H. courbaril immature leaf toH. courbaril mature leaf, and bean leaf disks toH. courbaril newly emerged leaf disks. From these results, we conclude thatH. courbaril leaf resins possess toxic and feeding-deterrent properties which make them effective as an herbivore defense.
TL;DR: With the addition of compound I, slightly attractive extract from mated females became nearly as active as extract from virgin females.
Abstract: Laboratory bioassays (two methods) and field tests demonstrated synergistic action of the three components [(−)-4-methyl-3-heptanol (I); (−)-2,4-dimethyl-5-ethyl-6,8-dioxabicylo[3.2.1]octane (α-multistriatin) (II); and (−)-α-cubebene (III)] of the pheromone bouquet ofScolytus multistriatus. Individually and in pairs the components were slightly attractive; I+II was clearly the most active doublet. Indirect evidence indicates that only one of the four enantiomers of I is active. Of the α, β, γ and δ isomers of II, only the α is active. With the addition of compound I, slightly attractive extract from mated females became nearly as active as extract from virgin females.
TL;DR: In this article, the α-farnesene levels in the outer coating of developing fruit of ten varieties of apple were monitored at fortnightly intervals from fruit set to harvest.
Abstract: α-Farnesene levels in the outer coating of developing fruit of ten varieties of apple were monitored at fortnightly intervals from fruit set to harvest. The compound was present in all varieties and the total amount on individual fruit increased with increasing fruit size. However, varieties differed in the levels of α-farnesene/unit area of apple skin, with two peaks evident in some varieties during the season. The relationship between varietal and seasonal variation in α-farnesene production and the ecology and behavior of codling moth adults and larvae is discussed.
TL;DR: Three quinones and two phenols were isolated from the defensive secretions of four species of opilionids (suborder Laniatores) from the Canal Zone.
Abstract: Three quinones (2,3-dimethyl-1,4-benzoquinone; 2,5-dimethyl 1,4-benzoquinone; and 2,3,5-trimethyl-1,4-benzoquinone) and two phenols (2,3-dimethylphenol and 2-methyl-5-ethylphenol) were isolated from the defensive secretions of four species of opilionids (suborder Laniatores) from the Canal Zone. Phenols had not previously been reported from opilionids, and 2-methyl-5-ethylphenol was not known as a natural product. The secretions, which are mixed with regurgitated enteric fluid upon discharge, are administered by the animals by leg dabbing.
TL;DR: An alarm pheromone, C15H24, was isolated from the spotted alfalfa aphid,Therioaphis maculata, and the IR, PMR, and [13C]NMR data showed that this alarm phersomone is germacrene A (structure IIIa).
Abstract: An alarm pheromone, C15H24, was isolated from the spotted alfalfa aphid,Therioaphis maculata. The IR, PMR, and [13C]NMR data showed that this alarm pheromone is germacrene A (structure IIIa). The negative plain curve in the ORD of the alarm pheromone implies that the pheromone is (−)-germacrene A (structure IIIb).
TL;DR: Monoterpene composition of xylem oleoresin in pole-size loblolly pine (Pinus taeda L.) was different between moisture-stressed and -unstressed trees during two test years.
Abstract: Monoterpene composition of xylem oleoresin in pole-size loblolly pine (Pinus taeda L.) was different between moisture-stressed and -unstressed trees during two test years. α-Pinene concentration increased in stressed trees whereas β-pinene, myrcene, and limonene decreased. Variations in camphene concentration with soil moisture stress were inconclusive. It increased with moisture stress in one test year and decreased in stressed trees during the other test year.
TL;DR: When placed in aY-maze, the 1–10-day-old free-swimming fry of the Midas cichlid can chemically distinguish between their mother and plain water and between another mother andplain water.
Abstract: When placed in aY-maze, the 1–10-day-old free-swimming fry of the Midas cichlid can chemically distinguish between their mother and plain water and between another mother and plain water. They do not distinguish between the two mothers offered together or between their father and plain water. Predation pressures make these responses adaptive.
TL;DR: In this article, the presence or absence of sex pheromone, the length of time since last exposure to pheromsone, and the duration of that exposure were all associated with male sexual response.
Abstract: Male sexual response inPeriplaneta americana is influenced by the presence or absence of sex pheromone, the length of time since last exposure to pheromone, the length of that exposure, and the photocycle. Females begin emission of sex pheromone 9 or more days after the molt to adult. The quantity emitted does not appear to be influenced by the photocycle. During the light phase of the photocycle, males only respond to high concentrations of pheromone. They recover quickly after brief exposures, but after prolonged exposures, a second exposure 24 h later elicited responses of lower intensity.
TL;DR: In this paper, a theory of host selection in Anteles melanoscelus is proposed based on gypsy moth silk kairomone [Lymantria dispar (L.)] and to host larvae.
Abstract: Choice experiments were performed to investigate details of femaleApanteles melanoscelus (Ratzeburg) behavior when exposed to gypsy moth silk kairomone [Lymantria dispar (L.)] and to host larvae when kairomone is present. Female parasites only responded to the kairomone when it had been placed on thin strands such as cotton fibers. Both gypsy moth silk and silk glands contain the same or similar kairomones. Silk gland extracts were more active than head, alimentary canal, or hemolymph extracts of host larvae. Female responses decreased when low concentrations of silk gland extract or small numbers of treated fibers were presented to them. Silk gland extract was stable when frozen for 2 weeks, heated to 100 °C for 0.5 hr, freeze dried, or treated with 95% ethanol. The active component was nondialyzable. Silk deposited on the substrate increased host contacts and oviposition attempts, more so if wider areas were covered with silk, and even if the areas having silk were separated from the host. A theory of host selection inA. melanoscelus is proposed.
TL;DR: Ipsenol, one component of the attractant pheromone ofIps paraconfusus, inhibits attacks byIps pini on ponderosa pine logs baited with maleI.
Abstract: Linalool, a compound from maleI. pini, previously suggested as an inhibitor forI. paraconfusus, has no obvious effect on the response ofI. paraconfusus to ponderosa pine bolts containing maleI. paraconfusus. I. pini from California and New York equally inhibit the response ofI. paraconfusus to maleI. paraconfusus. Ipsenol, one component of the attractant pheromone ofIps paraconfusus, inhibits attacks byIps pini on ponderosa pine logs baited with maleI. pini. The concentration of ipsenol used appears to be critical for effective suppression of attacks.
TL;DR: This secretion appears to impair the healing of wounds in test ants, and thus could represent a valuable supplement to the mechanical defense mechanism.
Abstract: Soldiers of the East African fungus-growing termiteMacrotermes subhyalinus (Rambur) (Termitidae: Macrotermitinae) employ both mechanical and chemical defenses. Soldiers release a chemical secretion composed of long-chain saturated and monounsaturated hydrocarbons into wounds inflicted by their powerful mandibles. Chemical analysis of the secretion shows the paraffin fraction to consist primarily ofn-tricosane,n-pentacosane, 3- and 5-methylpentacosane, and 5-methylheptacosane. The major oleflns were identified as (Z)-9-heptacosene and (Z)-9-nonacosene. The secretion originates from the frontal glands of both major and minor soldiers; however, the hypertrophied gland of the major soldiers contains 500-fold more secretion than that of the minor soldiers. This secretion appears to impair the healing of wounds in test ants, and thus could represent a valuable supplement to the mechanical defense mechanism.
TL;DR: Synthetic (Z)-14-methyl-8-hexadecenal elicits attraction and sexual arousal in T. Variabile males and is identified as a potent sexual excitant and attractant for the male beetles.
Abstract: Females of the dermestid beetle,Trogoderma variabile Ballion, exhibit a diel pattern of calling behavior. A potent sexual excitant and attractant for the male beetles can be collected on Porapak Q during aeration of female beetles, but cannot be detected in extracts of macerated females. The attractant has been identified as (Z)-14-methyl-8-hexadecenal. Of the five additional compounds previously identified as attractants in otherTrogoderma species, only two were found; (Z)-14-methyl-8-hexadecen-1-ol is present in extracts of macerated female beetles, but not in extracts of Porapak Q, and γ-caprolactone is present in extracts of Porapak Q. Three collection procedures were necessary to ensure that all the pheromone components had been isolated. Synthetic (Z)-14-methyl-8-hexadecenal elicits attraction and sexual arousal inT. Variabile males.
TL;DR: The concentrations of most Phenolics in leaves increased as the growing season progressed, whereas those of most phenolics in bark remained essentially unchanged.
Abstract: Catechin, quercitrin, robinin, quercetin 3-methyl ether, scopoletin, cholorogenic acid, several leucoanthocyanins, and condensed and hydrolyzable tannins were identified in bark and leaves ofQuercus velutina Lamarck. The concentrations of most phenolics in leaves increased as the growing season progressed, whereas those of most phenolics in bark remained essentially unchanged. Qualitative differences in bark and leaf phenolics among different trees were negligible.
TL;DR: The recency of common origin of seven species is discussed and the most important component emitted by four of the species is (Z)- or (E)-14-methyl-8-hexadecenal, which is not detectable in extracts of macerated beetles.
Abstract: Interspecific responses among severalTrogoderma species have been correlated with their pheromone components. The most important component emitted by four of the species is (Z)- or (E)-14-methyl-8-hexadecenal, which is not detectable in extracts of macerated beetles. The response to macerated beetles is probably due to the corresponding alcohol and ester. The recency of common origin of seven species is discussed.