Characteristic odor of Osmoderma eremita identified as a male-released pheromone

Osmoderma eremita (Scopoli) is an endangered scarab beetle living in hollow trees. It has mainly been known for its characteristic odor, typically described as a fruity, peachlike or plumlike aroma. The odor emanating from a single beetle can sometimes be perceived from a distance of several meters. In this paper, we show that the characteristic odor from O. eremita is caused by the compound (R)-(+)--decalactone, released in large quantities mainly or exclusively by male beetles. Antennae from male and female beetles responded in a similar way to (R)-(+)--decalactone in electroantennographic recordings. Field trapping experiments showed that (R)-(+)--decalactone is a pheromone attracting female beetles. Lactones similar to (R)-(+)--decalactone are frequently used as female-released sex pheromones by phytophagous scarabs. This is, however, the first evidence of a lactone used as a male-produced pheromone in scarab beetles. We propose that the strong signal from males is a sexually selected trait used to compete for females and matings. The signal could work within trees but also act as a guide to tree hollows, which are an essential resource for O. eremita. Males may, thus, attract females dispersing from their natal tree by advertising a suitable habitat. This signal could also be exploited by other males searching for tree hollows or for females, which would explain the catch of several males in our traps.     

Host Plant Volatiles Synergize Response to Sex Pheromone in Codling Moth, Cydia pomonella

Plant volatile compounds synergize attraction of codling moth males Cydia pomonella to sex pheromone (E,E)-8,10-dodecadien-1-ol (codlemone). Several apple volatiles, known to elicit a strong antennal response, were tested in a wind tunnel. Two-component blends of 1 pg/min codlemone and 100 pg/min of either racemic linalool, (E)-beta-farnesene, or (Z)-3-hexen-1-ol attracted significantly more males to the source than codlemone alone (60, 58, 56, and 37%, respectively). In comparison, a blend of codlemone and a known pheromone synergist, dodecanol, attracted 56% of the males tested. Blends of pheromone and plant volatiles in a 1:100 ratio attracted more males than 1:1 or 1:10,000 blends. Adding two or four of the most active plant compounds to codlemone did not enhance attraction over blends of codlemone plus single-plant compounds. Of the test compounds, only farnesol was attractive by itself; at a release rate of 10,000 pg/min, 16% of the males arrived at the source. However, attraction to a 1:10,000 blend of codlemone and farnesol (42%) was not significantly different from attraction to codlemone alone (37%). In contrast, a codlemone mimic, (E)-10-dodecadien-1-ol, which attracted 2% males by itself, had a strong antagonistic effect when blended in a 1:10,000 ratio with codlemone.     

Male-Released Sex Pheromone of the Stink Bug Piezodorus hybneri

Male-released semiochemicals of the stink bug Piezodorus hybneri (Heteroptera: Pentatomidae) elicit attraction of male and female bugs and homosexual behavior in males. Three active components were isolated from the airborne volatiles of males by flash chromatography, with the activity monitored by GC-EAD and behavioral bioassay. The pheromone system was characterized as a mixture of -sesquiphellandrene, (R)-15-hexadecanolide, and methyl 8-(Z)-hexadecenoate (ratio: 10:4:1), and the activity of the semiochemicals was assessed with authentic samples. Enantiomerically pure samples of the R and S macrolactones were obtained by Yamaguchi's and Mitsunobu's macrolactonization of a key intermediate, (R)-15-hydroxyhexadecanoic acid. The nonnatural S stereoisomer was neither a beneficial nor a behavioral antagonist. Individual constituents or binary mixtures were active, but the optimal male response was elicited only by the full mixture. Behavioral observation and the fact that the onset of pheromone production is coincident with ovarian development strongly suggest that these semiochemicals are, in fact, sex pheromones.     

Host Attractants for Red Weevil, Rhynchophorus ferrugineus: Identification, Electrophysiological Activity, and Laboratory Bioassay

A steam distillate from the freshly cut young bark of coconut palm Cocos nucifera was analyzed by gas chromatography, combined gas chromatography–electroantennographic detection (GC-EAD) and GC-MS to detect host attractants for the curculionid weevil Rhynchophorus ferrugineus, one of the major coconut pests in Sri Lanka. A twin FID peak consisting of a minor and a major component was shown to possess electrophysiological (EAG) activity. The minor peak was identified as -nonanoic lactone 1, while the major peak was identified as 4-hydroxy-3-methoxystyrene 2. In an EAG assay the synthetic racemic nonanoic lactone 1 did not elicit a considerable response in the antenna of R. ferrugineus, whereas the laboratory synthesized 2 showed activity. In a laboratory bioassay using a Y-type olfactometer, synthetic 1 and 2 elicited moderate attractant properties to R. ferrugineus, whereas a 1:1 mixture of the compounds showed increased attraction over that of the individual compounds.     

Ontogeny of Alarm Pheromone Secretion in Pea Aphid, Acyrthosiphon pisum

When attacked by a predator, an aphid may secrete a droplet of fluid from its cornicles containing a volatile alarm pheromone component, (E)--farnesene. This study investigated both qualitative and quantitative aspects of alarm pheromone production in the pea aphid, Acyrthosiphon pisum. The best predictor of cornicle droplet emission was reproductive phase, rather than instar, as prereproductive aphids were more likely to secrete cornicle droplets than either reproductive or postreproductive individuals. Analogously, alarm pheromone amounts were highest in prereproductive aphids. (E)--Farnesene quantities (mean ± SE) increased significantly from first instar (1.5 ± 0.6 ng) to second instar (11.2 ± 3.7 ng) and did not significantly change during third (12.8 ± 3.0 ng) or fourth instars (11.0 ± 3.7 ng). Alarm pheromone amounts then decreased significantly in adults (4.8 ± 2.3 ng). We suggest that prereproductive aphids have been selected to produce higher levels of pheromone because of their more clustered colony structure and higher levels of predation, as compared with adult aphids.     

Laboratory and Field Study of the Attraction of Male Pea Midges, Contarinia pisi, to Synthetic Sex Pheromone Components

Behavioral activity of the recently identified sex pheromone components of the pea midge, Contarinia pisi, (2S,11S)-diacetoxytridecane, (2S,12S)-diacetoxytridecane, and 2-acetoxytridecane, was tested in wind tunnel and field-trapping experiments. In the wind tunnel, the attractancy of the three-component blend in a 7 : 10 : 0.1 ratio (following the above order, mimicking the ratios found in gland extract) did not differ significantly from female gland extract, whereas a mixture of the two major components (7 : 10) only attracted 2% of the males to the source. In the field, traps baited with the three-component blend caught by far the largest number of males. Traps baited with the two major components only caught slightly more than the blank traps, and catches in traps baited with 2-acetoxytridecane alone did not differ from catches in the blank traps. Traps baited with the racemate of all three components did not catch more than the blank traps, indicating that some of the enantiomers are inhibitory.     

Response of the Seven-spot Ladybird to an Aphid Alarm Pheromone and an Alarm Pheromone Inhibitor is Mediated by Paired Olfactory Cells

Electrophysiological responses of adult seven-spot ladybirds, Coccinella septempunctata, to (E)--farnesene, an aphid alarm pheromone, and (–)--caryophyllene, a plant-derived alarm pheromone inhibitor, were investigated by recording from single olfactory cells (neurons) on the antenna. Cells having high specificity for each of the two compounds were identified. Furthermore, these two cell types were frequently found in close proximity, with a larger amplitude consistently recorded for the cell responding specifically to (E)--farnesene. Preliminary behavioral studies in a two-way olfactometer showed that walking adults were significantly attracted to (E)--farnesene; this activity was inhibited with increasing proportions of (–)--caryophyllene. The possible ecological significance of colocation or pairing of olfactory cells for semiochemicals with different behavioral roles is discussed.     

Chemical identification and behavioral characterization of male wing pheromone ofEphestia elutella (Pyralidae)

Behavioral and chemical evidence is presented for the identity of the male wing pheromone ofEphestia elutella (Hübner) and the role of this pheromone in courtship success is evaluated. Males with the forewing removed experienced a mating success rate less than half of that of either intact males or males that had only the wing gland area remaining of their forewings. GC-MS analysis and microchemical reactions indicated the presence of (E)-phytol and a series of saturated -lactones in a methylene chloride extract of the wings. Using an assay of female courtship behavioral response, (E)-phytol was found to evoke an intermediate level of response in females when presented alone, while the complete array of insect-derived -lactones produced no significant response. The combination of either -decalactone or -undecalactone with (E)-phytol in a 12 ratio, however, elicited a female response equivalent to that produced by the unfractionated wing extract.     

Response of The Lacewing Chrysopa cognata to Pheromones of its Aphid Prey

The lacewing Chrysopa cognata, one of the principal predators of aphids in Korea, was tested for responses to the aphid sex pheromone components (4aS,7S,7aR)-nepetalactone and (1R,4aS,7S,7aR)-nepetalactol and the aphid alarm pheromone (E)--farnesene. Electroantennogram responses were obtained to the sex pheromone components but not to (E)--farnesene. The sex pheromone components were attractive in a Y-tube olfactometer assay and in field trials with water traps, but no attraction was observed to (E)--farnesene.     

Sex Pheromone Components of Indian Gypsy Moth, <Emphasis Type="Italic">Lymantria obfuscata</Emphasis>

The Indian gypsy moth, Lymantria obfuscata (Lepidoptera: Lymantriidae), has been recognized as a distinct species since 1865 but closely resembles a diminutive form of gypsy moth, Lymantria dispar. We tested the hypothesis that the sex pheromones of L. obfuscata and L. dispar are similar. In laboratory mate acceptance studies, very few male L. dispar made copulatory attempts when paired with female L. obfuscata, suggesting that female L. obfuscata emit one or more pheromone components antagonistic to male L. dispar. In coupled gas chromatographic–electroantennographic detection (GC–EAD) analyses of pheromone gland extract of female L. obfuscata, (Z)-2-methyloctadec-7-ene (2Me-7Z-18Hy) and (7R,8S)-cis-7,8-epoxy-2-methyloctadecane [(+)-disparlure] were most abundant and elicited the strongest responses from male L. obfuscata antennae. In field experiments near Solan (Himachal Pradesh, India), 2Me-7Z-18Hy and (+)-disparlure in combination attracted more male L. obfuscata than did either component alone. This two-component sex pheromone contrasts with the single-component sex pheromone [(+)-disparlure] of L. dispar. The contrasting composition of the lymantriid communities inhabited by L. obfuscata and L. dispar may explain why 2Me-7Z-18Hy is a pheromone component in L. obfuscata and a pheromone antagonist in L. dispar and why (−)-disparlure reduces pheromonal attraction of male L. dispar but not male L. obfuscata.     

Evaluation of the Major Female Eurytoma amygdali Sex Pheromone Components, (Z,Z)-6,9-Tricosadiene and (Z,Z)-6,9-Pentacosadiene for Male Attraction in Field Tests

We evaluated the attraction of male almond seed wasp Eurytoma amygdali to the synthetic alkadienes (Z,Z)-6,9-tricosadiene and (Z,Z)-6,9-pentacosadiene and their blend in almond orchards using baited rubber septa attached to cardboard rectangular adhesive traps. The two alkadienes were recently isolated from virgin female whole body extracts and SPME collected volatiles. The alkenes (Z)-9-tricosene, (Z)-9-pentacosene, and (Z)-9-heptacosene, present in female extracts, were also added to the blend of the alkadienes and tested. The alkadienes tested individually attracted males when the traps were baited with doses ranging from 10 to 30 mg/trap. The maximum number of males was attracted to traps baited with 10 mg of a (Z,Z)-6,9-C(23:2):(Z,Z)-6,9-C(25:2) blend at a ratio of 7:3. Results with the three alkenes added to the blend were inconclusive because of low populations. The present study on E. amygdali is the first one reporting attraction of males to synthetic sex pheromone components in field trials for a Eurytomidae species. The synthetic alkadienes blend offers the potential to develop an effective system for monitoring populations of the almond seed wasp in almond orchards.     

Attraction of Male European Tarnished Plant Bug, <Emphasis Type="Italic">Lygus rugulipennis</Emphasis> to Components of the Female Sex Pheromone in the Field

Previous work showed that females of the European tarnished plant bug, Lygus rugulipennis Poppius (Heteroptera: Miridae), produced three chemicals, hexyl butyrate, (E)-2-hexenyl butyrate, and (E)-4-oxo-2-hexenal, and that these were suspected to be components of the female sex pheromone. In field experiments, traps baited with blends of these chemicals dispensed from polyethylene vials and sachets failed to catch significant numbers of males. Here, we report more recent field experiments in which the chemicals were released from glass microcapillary tubes. A blend of hexyl butyrate and (E)-4-oxo-2-hexenal was significantly attractive to male L. rugulipennis. In addition, whereas the mixture of all three components attracted fewer L. rugulipennis males, this tertiary blend captured significantly greater numbers of males of the congeneric species Lygus pratensis than the binary mixture. The possible reasons for the success of the microcapillaries compared with other dispensers are discussed.     

Hydroxybenzoic Acid Derivatives in a Nonhost Rutaceous Plant, Orixa japonica, Deter Both Oviposition and Larval Feeding in a Rutaceae-Feeding Swallowtail Butterfly, Papilio xuthus L.

A Rutaceae-feeding swallowtail butterfly. Papilio xuthus L., feeds on various rutaceous plants but always rejects Orixa japonica Thunb. (Rutaceae). Females were strongly deterred from laying eggs by a methanolic extract of O. japonica leaves. Larvae also rejected a diet leaf medium impregnated with O. japonica leaf extracts. Several components in the water-soluble fraction of the leaf extract were found to deter both oviposition and feeding responses. Two major deterrent compounds were characterized as 5-[[2-O-(beta-D-apiofuranosyl)-beta-D-glucopyranosyl]oxy]-2-hydroxybenzoic acid and adisyringoyl aldaric acid. These compounds induced potent deterrence of both oviposition and larval feeding by P. xuthus, which suggests a congruent chemosensory mechanism of allomonal chemicals acting on both female tarsal chemoreceptors and larval maxillary taste receptors.     

Using Generic Pheromone Lures to Expedite Identification of Aggregation Pheromones for the Cerambycid Beetles Xylotrechus nauticus, Phymatodes lecontei, and Neoclytus modestus modestus

Males of several species of longhorned beetles in the subfamily Cerambycinae produce sex or aggregation pheromones consisting of 2,3-hexanediols and/or hydroxyhexanones. We tested the hypothesis that this diol/hydroxyketone pheromone motif is highly conserved within the subfamily, and the resulting prediction that multiple cerambycine species will be attracted to compounds of this type. We also tested the concept that live traps baited with generic blends of these compounds could be used as a source of live insects from which pheromones could be collected and identified. Traps placed in a mature oak woodland and baited with generic blends of racemic 2-hydroxyhexan-3-one and 3-hydroxyhexan-2-one captured adults of both sexes of three cerambycine species: Xylotrechus nauticus (Mannerheim), Phymatodes lecontei Linsley, and Phymatodes decussatus decussatus (LeConte). Odors collected from male X. nauticus contained a 9:1 ratio of two male-specific compounds, (R)- and (S)-3-hydroxyhexan-2-one. Field trials with synthetic compounds determined that traps baited with (R)-3-hydroxyhexan-2-one (94% ee), alone or in blends with other isomers, attracted similar numbers of X. nauticus of both sexes, whereas (S)-3-hydroxyhexan-2-one (94% ee) attracted significantly fewer beetles. Phymatodes lecontei and P. d. decussatus also were caught in traps baited with hydroxyhexanones, as well as a few specimens of two other cerambycine species, Neoclytus modestus modestus Fall (both sexes) and Brothylus gemmulatus LeConte (only females). Male N. m. modestus produced (R)-3-hydroxyhexan-2-one, which was not present in extracts from females. Neoclytus m. modestus of both sexes also responded to lures that included (R)-3-hydroxyhexan-2-one as one of the components. The only male-specific compound found in extracts from P. lecontei was (R)-2-methylbutan-1-ol, and adults of both sexes were attracted to racemic 2-methylbutan-1-ol in field bioassays. Surprisingly, P. lecontei of both sexes also were attracted to (R)- and (S)-3-hydroxyhexan-2-ones, although neither compound was detected in extracts from this species. Males of all five beetle species had gland pores on their prothoraces that were similar in structure to those that have been associated with volatile pheromone production in other cerambycine species. The attraction of multiple cerambycine species of two tribes to (R)-3-hydroxyhexan-2-one in this study, and in earlier studies with other cerambycine species, suggests that this compound is a widespread aggregation pheromone component in this large and diverse subfamily. Overall, the attraction of multiple species from different cerambycine tribes to this compound at a single field site supports the hypothesis that the hydroxyketone pheromone structural motif is highly conserved within this subfamily.     

Sex pheromone components of the giant looper,Boarmia selenaria schiff. (Lepidoptera: Geometridae): Identification,synthesis, electrophysiological evaluation,and behavioral activity

(Z,Z)-6,9-cis-(3S,4R)-Epoxynonadecadiene9a and (Z,Z,Z)-3,6,9-nonadecatriene have been identified as sex pheromone components in female ovipositor extracts and effluvia of the geometridBoarmia selenaria. The identification was based on relative retention times on gas chromatographic columns, GC-MS, chemical enantioselective syntheses, EAG, wind-tunnel behavioral experiments, and field tests. A single female ovipositor extract contained an average of 42 ng of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene and 2 ng of (Z,Z,Z)-3,6,9-nonadecatriene.EAG, wind-tunnel behavioral studies, and field tests demonstrated that maleB. selenaria exhibit preferential attraction for the (3S,4R)-enantiomer of (Z,Z)-6,9-cis-3,4-epoxynonadecadiene. Only in effluvia and ovipositor extracts of calling females was (Z,Z)-6,9-cis- 3,4-epoxynonadecadiene detected, whereas relatively high amounts of (Z,Z,Z)-3,6,9-nonadecatriene were found in noncalling females. Wind-tunnel behavioral studies showed that (Z,Z,Z)-3,6,9-nonadecatriene did not elicit any response in the males, and when tested in combination with a mixture of monoepoxynonadecadienes, (Z,Z,Z)-3,6,9-nonadecatriene decreased the observed behavioral responses. A possible precursor role for (Z,Z,Z)-3,6,9-nonadecatriene in the pheromonal system is discussed.     

Simple and economic syntheses of some (Z)-7- and (Z)-9-alkenyl acetates,and of (E,Z)-7,9-dodecadien-1-yl acetate,the sex pheromone of the European grapevine moth,using aleuritic acid as a common starting material

Short syntheses of (Z)-7-dodecen-1-yl acetate, (Z)-7-tetradecen-1-yl acetate, (Z)-9-dodecen-1-yl acetate, and (Z)-9-tetradecen-1-yl acetate from 7-hydroxyheptanal and 9-oxononanoic acid precursors obtained by oxidative cleavage of easily available aleuritic acid are reported. The key step in these syntheses is a stereoselective Wittig reaction between aldehyde and alkyl-phosphonium salt. Wittig-Horner type reaction of 7-hydroxyheptanal and diethyl cyanomethylphosphonate gave the ,-unsaturated nitrile derivative which after protection of the hydroxyl group was reduced to the corresponding aldehyde. Wittig reaction of the latter, followed by acetylation, completed the synthesis of (E,Z)-7,9-dodecadien-1-yl acetate, the sex pheromone of the European grapevine mothLobesia botrana Schiff.     

Stereospecific antennal response by red turpentine beetle,Dendroctonus valens to chiral monoterpenes from ponderosa pine resin

The antennal response ofDendroctonus valens to host monoterpenes from the resin of ponderosa pine was studied using the electroantennogram (EAG) technique. Male and female beetles were given a single dose of each of 11 different monoterpenes. Response amplitude to the different compounds did not vary between sexes and was generally well correlated with results from field attraction studies. Response to (S)-(–)--pinene was greatest. The relative amplitude of the responses to the (R)-(+) and (S)-(–) enantiomers of a-pinene, however, were reversed from their relative attractiveness in the field. A dose-response study was conducted for the (R)-(+) and (S) -(–) enantiomers of a-pinene, plus a reciprocal differential saturation test with successive doses of first one enantiomer of-pinene and then the other. Comparison of EAG traces suggests different receptors for the two stereoisomers of-pinene. Differential saturation curves suggest that while one set of receptors may respond to both enantiomers, some receptors respond only to the (S)-(–) enantiomer.     

Chemistry and Defensive Efficacy of Secretion of Burrowing Bug (Sehirus cinctus cinctus)

Adult Sehirus cinctus cinctus emit a volatile secretion from their metathoracic scent glands when tactually stimulated. We identified the volatile components by gas chromatography, high-performance liquid chromatography, and mass spectrometry. The secretion of both sexes contained (1R)-(+)--pinene, (1S)-(–)--pinene, -myrcene, (R)-(+)-limonene, and -terpinolene. Two additional compounds were found in only female secretions: (E)-2-hexenyl acetate and (E)-2-octenal. We also tested the defensive capability of this insect by offering it to various predators. Anoles, starlings, and a killdeer rejected S. c. cinctus after an initial sampling. These findings suggest that the secretion plays a defensive role.     

Floral Scent of Osmanthus fragrans Discourages Foraging Behavior of Cabbage Butterfly, Pieris rapae

Field observations revealed that flowers of Osmanthus fragrans attract 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 -decalactone, -ionone, and linalool oxide (LO) isomers (furanosides and pyranosides) as major components together with small amounts of linalool and -ionone. -Decalactone was strongly deterrent in the PER test, and -ionone and all LO isomers were weakly deterrent, while the other compounds exhibited no deterrency. In the flower-visiting tests, -decalactone showed notable repellency, whereas -ionone had no repellent effect. Among the LO isomers, at least furanosides (cis/trans mixture) 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, -decalactone, and -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.     

Attraction of bark beetles,Tomicus piniperda,Hylurgops palliatus,andTrypodendron domesticum and other insects to short-chain alcohols and monoterpenes

Several Scandinavian forest insects,Hylurgops palliatus, Tomicus piniperda, andTrypodendron domesticum (Coleoptera: Scolytidae),Rhizophagus ferrugineus (Coleoptera: Rhizophagidae) andPollenia spp. (Diptera: Calliphoridae) were attracted to window traps baited with ethanol and placed on Scots pine trees (Pinus sylvestris) in May–June, 1986. Release of ethanol at increasing relative rates of 0, 0.01, 0.1 and 1.0 (800 mg/day) from the window traps on trees in 1987 causedH. palliatus, T. domesticum, andR. ferrugineus to be increasingly attracted, whileT. piniperda was equally attracted at both 0.1 and 1.0 rates. The attraction ofT. piniperda to ethanol was weak compared to attraction to a monoterpene mix, (±)--pinene, (+)-3-carene, terpinolene. The terpene mix plus ethanol was significantly more attractive toH. palliatus than ethanol alone, but terpenes significantly reduced the attraction ofT. domesticum to ethanol. Baiting of pipe traps with a series of short-chain alcohols (methanol to hexanol) each alone showed that ethanol was greatly preferred byH. palliatus, T. domesticum, andR. ferrugineus over alcohols of one more or one less carbon, while longer-chain alcohols were not attractive. However,Glischrochilus hortensis (Col.: Nitidulidae) was attracted only to propanol. A series of 10-fold increasing release rates of ethanol (0.0001-1.0, where 1.0=800 mg/day) with either a low or high release of the terpene mix had various effects on the sexes during their attraction to pipe traps and subsequent entering of holes. Release of (–)-verbenone at 0.25 mg/day had no significant effect onH. palliatus orR. ferrugineus attraction to ethanol, but the response ofT. domesticum to ethanol was reduced. Several theories on olfactory mechanisms of host selection byT. piniperda are integrated and placed in ecological perspective.