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Terpenes constitute a major part of secondary metabolites secreted by plants in the rhizosphere. However, their specific functions in fungal–plant interactions have not been investigated thoroughly. In this study we investigated the role of monoterpenes in interactions between oilseed rape (Brassica napus) and the soilborne pathogen Verticillium longisporum. We identified seven monoterpenes produced by B. napus, and production of α‐pinene, β‐pinene, 3‐carene, and camphene was significantly increased upon fungal infection. Among them, β‐pinene was chosen for further analysis. Transcriptome analysis of V. longisporum on exposure to β‐pinene resulted in identification of two highly expressed pleotropic drug transporters paralog genes named VlAbcG1a and VlAbcG1b. Overexpression of VlAbcG1a in Saccharomyces cerevisiae increased tolerance to β‐pinene, while deletion of the VlAbcG1a homologous gene in Verticillium dahliae resulted in mutants with increased sensitivity to certain monoterpenes. Furthermore, the VlAbcG1a overexpression strain displayed an increased tolerance to β‐pinene and increased virulence in tomato plants. Data from this study give new insights into the roles of terpenes in plant–fungal pathogen interactions and the mechanisms fungi deploy to cope with the toxicity of these secondary metabolites., A pleotropic drug transporter VIAbcG1 is required for tolerance to the plant host β‐pinene monoterpene and virulence in the soilborne plant pathogen Verticillium longisporum.

Siren molecule calls loudly to mosquitoes People infected by malaria become more attractive to the mosquito vectors of the disease, which facilitates the spread of malaria. Emami et al. found that red blood cells of the host respond to a parasite-derived isoprenoid called HMBPP by increasing the production of carbon dioxide and several monoterpenes and aldehydes. Mosquitoes fed HMBPP-spiked blood displayed malaria parasite–specific changes in gene transcription, which reinforced attractiveness for the mosquito. HMBPP also stimulates mosquito feeding and malaria parasite reproduction. Thus, the parasite manipulates its mammalian host to make it more attractive to the insect vectors and exploits the same molecule to amplify transmission. Science , this issue p. 1076

The male butterfly Pieris napi produces the anti-aphrodisiac pheromone methyl salicylate (MeS) and transfers it to the female during mating. After mating she releases MeS, when courted by conspecific males, which decreases her attractiveness and the duration of male harassment, thus increasing her time available for egg-laying. In previous studies we have shown that males produced MeS from the amino acid L-phenylalanine (L-Phe) acquired during larval stage. In this study we show that adult males of P. napi can utilize L-Phe and aromatic flower volatiles as building blocks for production of anti-aphrodisiac pheromone and transfer it to females during mating. We demonstrate this by feeding butterflies with stable isotope labelled molecules mixed in sugar solutions, and, to mimic the natural conditions, we fed male butterflies with floral nectar of Bunias orientalis plants treated with labelled L-Phe. The volatiles from butterflies and plants were collected and identified by solid phase micro extraction, gas chromatography and mass spectrometry techniques. Since P. napi is polygamous, males would gain from restoring the titre of MeS after mating and the use of aromatic precursors for production of MeS could be considered as an advantageous trait which could enable butterflies to relocate L-Phe for other needs.

Most horticultural crops are attacked by more than one insect pest. As broad-spectrum chemical control options are becoming increasingly restricted, there is a need to develop novel control methods. Semiochemical attractants are available for three important horticultural pests, strawberry blossom weevil, Anthonomus rubi Herbst (Coleoptera: Curculionidae), European tarnished plant bug, Lygus rugulipennis Poppius (Hemiptera: Miridae) and raspberry beetle, Byturus tomentosus deGeer (Coleoptera: Byturidae). Traps targeting more than one pest species would be more practical and economical for both monitoring and mass trapping than traps for single-species. In this study we aimed to (1) improve the effectiveness of existing traps for insect pests in strawberry and raspberry crops by increasing catches of each species, and (2) test if attractants for two unrelated pest species could be combined to capture both in the same trap without decreasing the total catches. Field tests were carried out in four European countries and different combinations of semiochemicals were compared. A volatile from strawberry flowers, 1,4 dimethoxybenzene (DMB), increased the attractiveness of the aggregation pheromone to both sexes of A. rubi. The host-plant volatile, phenylacetaldehyde (PAA), increased the attraction of female L. rugulipennis to the sex pheromone, and, in strawberry, there was some evidence that adding DMB increased catches further. Traps baited with the aggregation pheromone of A. rubi, DMB, the sex pheromone of L. rugulipennis and PAA attracted both target species to the same trap with no significant difference in catches compared to those single-species traps. In raspberry, catches in traps baited with a combination of A. rubi aggregation pheromone, DMB and the commercially available lure for B. tomentosus, based on raspberry flower volatiles, were similar to those in single-species traps. In both crops the efficiency of the traps still needs improvement, but the multispecies traps are adequate for monitoring and should not lead to confusion for the user as the target species are easy to distinguish from each other.

Females of both species start their pheromone-releasing activity on the second day after emergence at the beginning of the photophase. During the present work, a peak of calling activity with close to 100% of active Ph. nigrescentella females was registered 1.5 hour after the light had been put on. The high pheromone release behaviour with 50% active females lasted for 3 hours. The calling activity of the group of females was about 6 h/day. The beginning of a photophase under laboratory conditions or an early morning in nature is a common period for sex pheromone release in the genus Phyllonorycter. (8Z,10E)-tetradecadien-1-yl acetate (8Z,10E-14:Ac), (8Z,10E)-tetradecadien-1-ol (8Z,10E-14:OH) and (8E,10Z)-tetradecadien-1-yl acetate (8E,10Z-14:Ac) in the ratio 96:4:traces as well as 8Z,10E-14:Ac and 8Z,10E-14:OH in the ratio 88:12 collected by Solid Phase Micro Extraction (SPME) were found to be specific for the calling periods of virgin Phyllonorycter insignitella and Ph. nigrescentella females respectively. Field trapping experiments demonstrated that all three compounds are important for the attraction of Ph. insignitella males while only 8Z,10E-14:Ac is the essential sex pheromone component for Ph. nigrescentella. The pheromone activity of all three compounds is reported for the first time. Addition of either 8Z,10E-14:OH or 8E,10Z-14:Ac to 8Z,10E-14:Ac did not have a significant effect on the attraction of Ph. nigrescentella males, while the efficiency of the three component blend was 5 times lower as compared to that of 8Z,10E-14:Ac. Our data demonstrate that 8Z,10E-14:OH and 8E,10Z-14:Ac play a dual function, they are minor sex pheromone components of Ph. insignitella essential for attraction of conspecific males and show an allelochemical, antagonistic effect on Ph. nigrescentella males and, thus, ensuring specificity of the mate location signal in two related Phyllonorycter species.

Introduction: For many insect species, pheromones and host plant volatiles are of major importance in mate finding and host plant location. Therefore, there is potential for using these interactions to develop new strategies and effective control measures. The strawberry blossom weevil (Anthonomus rubi), the European tarnished plant bug (Lygus rugulipennis) and the raspberry beetle (Byturus tomentosus) cause large losses (10->80%) in both conventional and organic strawberry and raspberry production. We investigated whether the natural semiochemical mechanisms of these key pests can be exploited to develop effective traps for their management through mass trapping. Methods: Attractive traps and lures with host plant volatiles and pheromones were developed and combined into a “multitrap” for management of these pests simultaneously. These traps were deployed within and around the perimeters of the soft berry fields. Insect catches were evaluated according to species, habitat and environmental variables. Plant damage was also assessed. Results/Conclusion: For both crops it was possible to combine lures so that different targeted insect species were caught in the same trap simultaneously, but optimal insect traps in strawberry were not the same as in raspberry. Perimeter traps and multiple traps placed inside the plantations showed the potential to reduce pest numbers and subsequent fruit damage. In addition, bycatch of non-targeted invertebrate species were low. Thus, it is possible to develop new plant protection strategies by using these techniques. In this paper we will discuss the benefits and difficulties in using these techniques as part of integrated or organic pest management.

The cabbage moth, Mamestra brassicae L. (Lepidoptera, Noctuidae), is a polyphagous species that is often choosing plants of Brassica as hosts for oviposition. In the search for biologically relevant odorants used by these moths, gas chromatography linked to electrophysiological recordings from single receptor neurons (RNs) has been employed, resulting in classification of distinct types of neurons. This study presents specific olfactory RNs responding to methyl salicylate (MeS) as primary odorant and showing a weak response to methyl benzoate, the 2 aromatic compounds occurring together in several plant species. In 2 cases, the neuron was colocated with another RN type responding to 6 green leaf volatiles: 1-hexanol, (3Z)-hexen-1-ol, (2E)-hexen-1-ol, (3Z)-hexenyl acetate, (2Z)-hexen-1-ol, and an unidentified compound. Whereas the specific RNs detected the minor amounts of MeS in some plants, the compound was not found by gas chromatography linked to mass spectrometry in intact plants, but it was found after herbivore attack. The behavioral effect of MeS was studied in outdoor test arenas with Brassica napus and artificial plants. These experiments indicated that mated M. brassicae females avoid plants with dispensers emitting MeS. As it is induced by caterpillar feeding, this compound may mediate a message to mated M. brassicae females that the plant is already occupied.

A chemical analysis of the crude sex pheromone gland extracts of virgin calling Paranthrene tabaniformis females, obtained from the European part of Kazakhstan, revealed the presence of five compounds: (3E,13Z)-octadeca-3,13-dien-1-ol (E3,Z13-18:OH), (3Z,13Z)- octadeca-3,13-dien-1-ol (Z3,Z13-18:OH), (2E,13Z)-octadeca-2,13-dien-1-ol (E2,Z13-18:OH), (13Z)-octadec-13-en-1-ol (Z13-18:OH), and octadecan-1-ol (18:OH) at the ratios 64.0 : 32.4 : 1.4 : 0.9 :1.3, which are structurally related to sex pheromone components of clearwing moths. Our previous field tests showed synergistic effects of Z3,Z13-18:OH and E2,Z13-18:OH to attract P. tabaniformis males, when these compounds were tested in binary mixtures with the known sex pheromone E3,Z13-18:OH. The three dienic alcohols should all be considered as sex pheromone components of the P. tabaniformis species, while the role of Z13-18:OH and 18:OH remained unclear.

The calling activity of virgin Phyllonorycter junoniella (Z.) females under a cycling thermal regime differed from that under constant temperature in the following ways: the percentage of females calling at the morning activity peak was increased; the morning period of calling activity was prolonged; the total period of calling activity of an individual female was increased; an extra peak of activity occurred at the end of the photophase, and females changed the calling pattern during the active period. We assume that the occurrence of two calling peaks and the extension of the calling period might be adaptive for a Ph. junoniella species with a sex ratio strongly shifted towards females (8:1 females:males), as it could lead to an increased proportion of females mated.

Sex attractants were established for one Brachodidae, three Choreutidae and two Tineidae moth species during field screening tests with (2E,13Z)-octadecadien-1-al, (2E,13Z)-, (3E,13Z)-, (3Z,13Z)-octadecadien-1-ols and their acetates (2E,13Z-18:Ald, 2E,13Z-, 3E,13Z-, 3Z,13Z-18:OH/OAc) as well as of binary mixtures of these compounds in West-Kazakhstan and Lithuania. Males of Brachodes appendiculata were attracted by 3E,13Z-18:OAc, Prochoreutis ultimana and P. myllerana by 2E,13Z-18:OH, Monopis palidella by 2E,13Z-18:Ald and Triaxomera fulvimitrella by binary mixtures of 3Z,13Z-18:OAc with either 3E,13Z-18:OH in the ratio of 5:5 or 3Z,13Z-18:OH in the ratio of 9:1 (v/v). The 3-component mixture composed of 2E,13Z-18:OH, 3Z,13Z-18:OH and 2E,13Z-18:Ald in the ratio 1:1:1 was developed to attract Prochoreutis sehestediana males. Attraction antagonists for B. appendiculata, P. ultimana and M. palidella were shown.

We proved that the leafminer moth Phyllonorycter emberizaepenella (Lepidoptera: Gracillariidae) reproduces by parthenogenesis of the thelytoky type. Despite a complete absence of males, parthenogenetically reproducing females diurnally demonstrated the calling posture normally used for releasing signaling compounds. Two compounds, which we collected from a calling female, were identified as potential sex pheromone components: (8E,10E)-8,10-tetradecadienyl acetate and (8E,10E)-8,10-tetradecadienol, the latter occurring only in trace amounts. In field experiments, no males were attracted to traps baited with either the potential sex pheromone or with virgin females. Both the pattern of behavior and the chemical characteristics of the pheromone of Ph. emberizaepenella species were similar to those known for Lepidoptera with the usual amphimictic mode of reproduction. Theoretical speculations that in thelytoky, where there is no need to find a sexual partner, the individuals would obtain certain advantages due to reduction in their sexual behavior, were, thus, not confirmed for Ph. emberizaepenella.

Sex attractants for 3 Sesiidae and 3 Tineidae moth species in West-Kazakhstan and Lithua­nia were discovered by field screening tests of (3Z,13Z)-, (3E,13Z)-and (2E,13Z)-octadeca-dien-1-ols and their acetates as well as of some binary mixtures of these compounds. Total amount of chemicals was 0.3 mg/dispenser. Males of Synanthedon serica were attracted by a 5:5 mixture of 3E,13Z-18:OA c and 2E,13Z-18:OAc, Chamaesphecia bibioniformis by a 9:1 mixture of 3Z,13Z-18:OAc and 3E,13Z-18:OAc, Paranthrene tabaniformis by a 1:9 mixture of 3Z,13Z-18:OH and 3E,13Z-18:OH , Tinea nonimella by a 1:9 mixture of 3E,13Z-18:OH and 2E,13Z-18:OH , Monopis monachella by a 1:9 mixture of 3Z,13Z-18:OH and 2E,13Z -18:OH, and Nemaxera betulinella by a 9:1 mixture of 2E,13Z-18:OAc and the corresponding alcohol. The periods of attraction to the traps were registered for males of S. serica and Ch. bibioniformis and were found to occur at 15 - 18 and 1 5 -17 o'clock, local time, respectively.

Females of the leaf miner moth Phyllonorycter acerifoliella (Z.) [=Ph. sylvella (Hw.)] and Ph. heegerella (Z.) (Lepidoptera: Gracillariidae: Lithocolletinae) release their sex pheromone at the beginning of photophase. The periodicity of the 'calling' behaviour of Ph. acerifoliella females was established. Three compounds from calling virgin Ph. heegerella females were collected by the Solid Phase Micro Extraction (SPME) technique and identified as (Z)-8-tetradecenyl acetate (Z8-14:OAc), tetradecyl acetate (14:OAc) and (Z)-8-tetradecenol (Z8-14:OH) in the ratio (88 +/- 3): (2 +/- 0.6) : (10 +/- 5) by capillary gas chromatography and mass spectrometry. Field trapping experiments demonstrated that the first two compounds are important for the attraction of conspecific males. Z814:OAc was found to be attractive when tested separately, while 14:OAc acted as synergist. The attractivity of the three component blend was reduced by 10% admixture of either (E)-10-dodecenyl acetate (E10-12:OAc) or (Z)-10-tetradecenyl acetate (Z10-14:OAc). Field tests of Z10-, Z8- and E10-14:OAc, identified from Ph. acerifoliella females, demonstrated that the first two compounds were essential for the attraction of conspecific males; so both are sex pheromone components. The attractivity of the three component bleed of Z10- Z8- and E10-14:OAc was reduced by 10% admixture of (E)10-dodecenol (E10-12:OH). The following four semiochemical compounds, Z8-14:OAc, Z8-14:OH, E10-14:OAc and 14:OAc, identified from phyllonoryctid females, as well as two sex attraction antagonists for Ph. acerifoliella and Ph. heegerella males, E10-12:OAc and Z10-14:OAc, are new for the family Gracillariidae. The results of field trapping experiments revealed mechanisms ensuring the specificity of the chemocommunication systems in Ph. acerifoliella, Ph. heegerella and Ph. ulmifoliella (Hb) moths.

Dodecyl acetate (12:OAc) (E)-10-dodecenyl acetate (E10-12:OAc) and (E)-10-dodecenol (E10-12:OH) in the ratio 8 : 80 : 12 were collected by solid phase micro-extraction of the volatiles emitted by virgin signalling females of the spotted tentiform leafminer moth, Phyllonorycter blancardella. The same compounds in the ratio 8 : 79 : 13 were extracted from the sex pheromone glands of virgin signalling females of the same species. The chemical structures of the compounds were identified by gas chromatography and mass spectrometry. Trapping results obtained from field tests using synthetic components of the sex pheromone demonstrated that only one component, E10–12:OAc, was essential for the attraction of conspecific males and should be considered as a sex pheromone.

The female sex pheromone of Bonagota (=Phthteochroa) cranaodes (Meyrick) is a blend of (E,Z)-3,5-dodecadienyl ajcetate (E3,Z5-12:Ac) and (Z)-9-hexadecenyl acetate (Z9-16:Ac) according to analysis of pheromone - gland extracts and field trapping in apple orchards. This is the first time that E3,Z5-12:Ac has been identified as a lepidopteran sex pheromone. Traps baited with 100 μg E3,Z5-12:Ac were attractive over 15 weeks in the field and were as effective as traps baited with virgin females. Addition of Z9-16:Ac to E3,Z5-12:Ac at ratio of 1:10 had a significantly increase of male moths. The addition of the Z,E and Z,Z isomers to rubber septa baited with E3,Z5-12:Ac did not modify B. cranaodes male attraction, but 10% of EE enhanced trap catch.

Field screening tests of (3Z,13Z)- and (3E,13Z)-octadecadienols, (2Z,13Z)-and (2E,13Z)-octadecadienols and their acetates as well as some binary mixtures of these compounds in dosages of 0.5 mg/dispenser were carried out in the Crimea, the Ukraine, and in the West Kopetdag mountains, Turkmenistan, in 1989-1993. New sex attractants for five clearwing moth species of the genus Chamaesphecia (Lepidoptera, Sesiidae) were discovered. Males of Ch. chalciformis were attracted by a 1:1 mixture of 3Z,13Z-18:OH and 2E,13Z-18:OAc, Ch. schmidtiformis by a 9:1 mixture of 3Z,13Z-18:OAc and 3Z,13Z-18:OH in the Ukraine as well as in the ratios 9:1 and 1:1 in Turkmenistan, Ch. mezentzevi by a 9:1 mixture of 3Z,13Z-18:OAc and the corresponding alcohol, Ch. zimmermanni by a 1:9 mixture of 3Z,13Z-18:OAc and 3.E,13Z-18:OH, and Ch. specia nova in Turkmenistan by a 1:1 mixture of 3Z,13Z-18:OH and 3E,13Z-18:OAc. Two inhibitors, 3Z,13Z-18:OH and 3E,13Z-18:OAc, of the sex attractant were found for Ch. zimmermanni. The periods of attraction to the traps were registered for males of Ch. zimmermanni and Ch. specia nova and were found to occur at 1900-2100 and 1430-1700 local time, respectively. Males of Ch. chalciformis and Ch. schmidtiform is were attracted to the traps in the afternoon.

Field screening tests of 21 saturated and monounsaturated straight chain C 12 and C 14 alcohols and their acetates as well as some binary mixtures in dosages of 1 and 0.2 mg/dispenser were carried out in Lithuanian in 1993 and 1994. New sex attractants were determined for males of five moth species of the family Gracillariidae (E10-12:OH for Phyllonorycter sorbi, E10-12Ac for Ph. cydoniella and Ph. oxyacanthae, Z10-12:OAc for Ph. junoniella, and a mixture of Z10-14:OAc with E9-14:OAc in a 1:10 for Ph. sylvella), for four species of the family Tortricidae (E10-14:OAc for Endothenia ericetana, Z10-14:OAc in a 10:1 mixture with E11-14:OAc for Eudemis pozphyrana, E11-14:OAc in a 10:1 mixture with E11-14:OH for Dichrorampha petiverella and Cochylis dubitana), for two species of Gelechiidae (Z9-14:OAc in a mixture with either Z10-14:OAc in a ratio 1:1, E9-14:OAc in a ratio 1:10 or E10-14:OAc in a ratio 10:1 for Bryotropha galbanella, Z10-14:OAc and E9-14:OAc in a ratio 10:1 for B. mundella), as well as for one species of each of the families Yponomeutidae (Z7-14:OAc for Paraswammerdamia lutarea) and Oecophoridae (Z10- 14:OAc and E9-14:OAc in a ratio 10:1 for Pseudatemelia josephinae). Preliminary composition of sex attractants was established for three moth species of the family Gracillariidae (Z10-14:OAc in a 1:10 mixture with E9-14:OAc for Phyllonorycter heegerella, Ph. coryli and Ph. dubitella) and for one species of the family Gelechiidae (Z9-14:OAc for Bryotropha terella). Inhibitors of the sex attractants were found for four leafminer species of the family Gracillariidae (Z7-, Z9- and Z10-12:OAc for Phyllonorycter sorbi, Z10-, E10-12:OH and E10-14:OH for Ph. mespilella, E10-12:OH for Ph. cydoniella, Z10-12:OH and E10-14:OH for Ph. oxyacanthae), for three species of Tortricidae (E9-, Z11- and E11-14:OAc for Endothenia ericetana, E11-14:OAc for Gypsonoma minutana, E10- and E11-14:OAc for Epagoge grotiana), and for one species from the family Pyralidae (Z10-, E10- and E11-14:OAc for Pyrausta aurata), Data from male behaviour tests in tube olfactometers are presented for Phyllonorycter blancardella, Ph. sorbi, Ph. dubitella and Ph. strigulatella and active compounds revealed.

International audience; The enormous burden placed on populations worldwide by mosquito-borne diseases, most notably malaria and dengue, is currently being tackled by the use of insecticides sprayed in residences or applied to bednets, and in the case of dengue vectors through reduction of larval breeding sites or larviciding with insecticides thereof. However, these methods are under threat from, amongst other issues, the development of insecticide resistance and the practical difficulty of maintaining long-term community-wide efforts. The sterile insect technique (SIT), whose success hinges on having a good understanding of the biology and behaviour of the male mosquito, is an additional weapon in the limited arsenal against mosquito vectors. The successful production and release of sterile males, which is the mechanism of population suppression by SIT, relies on the release of mass-reared sterile males able to confer sterility in the target population by mating with wild females. A five year Joint FAO/IAEA Coordinated Research Project brought together researchers from around the world to investigate the pre-mating conditions of male mosquitoes (physiology and behaviour, resource acquisition and allocation, and dispersal), the mosquito mating systems and the contribution of molecular or chemical approaches to the understanding of male mosquito mating behaviour. A summary of the existing knowledge and the main novel findings of this group is reviewed here, and further presented in the reviews and research articles that form this Acta Tropica special issue.

The SPME (solid phase micro extraction) technique was used in the collection of volatiles released by calling females of the 4 -6 mm long tentiform leafminer moth Phyllonorycter sylvella (Lepidoptera, Gracillariidae). The volatiles released by the calling P. sylvella females were identified by GC-M S as a mixture of Z10-tetradecenyl acetate (92 %), E10-tetrad ecen yl acetate (2 %) and Z8 -tetradecenyl acetate (6 %). The amount of volatiles released by one calling female during three hours and collected on a polydimethylsiloxane fibre, was as large as the amount extracted from the glands of 20 females. The SPME technique gives the opportunity of continuously following the release of behaviour mediated signals from weak scented living organisms.

Butterflies are believed to use mainly visual cues when searching for food and oviposition sites despite that their olfactory system is morphologically similar to their nocturnal relatives, the moths. The olfactory ability in butterflies has, however, not been thoroughly investigated. Therefore, we performed the first study of odour representation in the primary olfactory centre, the antennal lobes, of butterflies. Host plant range is highly variable within the butterfly family Nymphalidae, with extreme specialists and wide generalists found even among closely related species. Here we measured odour evoked Ca(2+) activity in the antennal lobes of two nymphalid species with diverging host plant preferences, the specialist Aglais urticae and the generalist Polygonia c-album. The butterflies responded with stimulus-specific combinations of activated glomeruli to single plant-related compounds and to extracts of host and non-host plants. In general, responses were similar between the species. However, the specialist A. urticae responded more specifically to its preferred host plant, stinging nettle, than P. c-album. In addition, we found a species-specific difference both in correlation between responses to two common green leaf volatiles and the sensitivity to these compounds. Our results indicate that these butterflies have the ability to detect and to discriminate between different plant-related odorants.

Two components of the female-produced sex pheromone of the hornet moth, Sesia apiformis, were identified as (3Z,13Z)-octadeca-3,13-dien-1-ol (3Z,13Z-18:OH) and (2E,13Z)-octadeca-2,13-dienal (2E,13Z-18:Al), a pheromone structure new in Sesiidae. Pooled gland extracts showed the two major compounds in a proportion of ca. 2:3, while SPME-investigations on single calling females revealed a ratio of ca. 1:7. Although the single compounds were not attractive, a 2:3 mixture proved to be highly active towards males in field tests. Small amounts of (2E,13Z)-octadecadienol (2E,13Z-18:OH) were found in the sex pheromone gland of females, however, the biological significance of the compound remains unclear. Methyl sulfide was found to readily react with 2-alkenals, providing an effective new method for the characterization of this type of compound upon GC/MS. The derivatives, 1,1,3-tris(methylthio)alkanes, are the products of the addition of methyl sulfide to the double bond and the transformation of the carbonyl group into the corresponding bis(methylthio)acetal. The mass spectra of these compounds are characterized by diagnostic signals at m/z 107 and/or m/z 121. These fragments represent the first carbon unit or the first two carbon units of the derivative, respectively. The parent signal in the spectra of thiomethyl derivatives of 2-alkenals showing no other double bonds is represented by m/z M+ – 121, formed upon loss of the first two carbon units. By employing a solution of methyl sulfide in dimethyl sulfide, the double bond positions in 2E,13Z-18:Al could be fully characterized by GC/MS.

The sesquiterpene germacrene D (GD) activates a major type of olfactory receptor neuron on the antennae of the heliothine moths. In Heliothis virescens females, 80% of the recordings have shown activity of one neuron type responding with high sensitivity and selectivity to GD. With the aim of determining the behavioural significance of this sesquiterpene, we have used a two-choice wind-tunnel to study the preference of mated H. virescens females for host plants with and without (-)-GD added. Tobacco plants containing dispensers with low release rate of (-)-GD had a greater attractiveness than tobacco plants without this substance. In addition, a significant increase of oviposition was found on the plants with (-)-GD.

Herbivore insects use a variety of search cues during host finding and mate recognition, including visual, gustatory, and olfactory stimuli, leaving multiple traits for evolution to act upon. However, information about differences or similarities in search pattern amongst closely related insect herbivore species is still scarce. Here, we study the production of and the response to pheromone in Galerucella (Coleoptera: Chrysomelidae) to investigate the beetles’ search behaviour. Males of G. pusilla and G. calmariensis, two closely related species, are known to produce the aggregation pheromone dimethylfuran-lactone when feeding on their host plant, whereas no pheromones have been identified in other Galerucella species. We show that dimethylfuran-lactone is produced also by males of G. tenella, a species phylogenetically close to G. pusilla and G. calmariensis, whereas the more distantly related species G. lineola and G. sagittariae were not found to produce the same compound. To investigate the beetles’ behavioural response to dimethylfuran-lactone, the pheromone was synthesized using a partly novel method and tested in olfactometers, showing that G. pusilla, G. calmariensis, and G. tenella were all attracted to the pheromone, whereas G. lineola and G. sagittariae did not respond. This suggests that the production of and the response to pheromone could be linked to the phylogenetic relatedness between the species.

Seven ♂♂ of Phyllonorycter trifoliella (Gerasimov 1933) were attracted to pheromone traps in Vilnius city in 2000. This is the first record of that species in the Lithuanian fauna. Ph trifoliella had been described from the Caucasus, environment of Krasnaya Polyana and Sochi, and was known only from that type locality for a long time. Lithuania is the third locality, where moths of this species were found. Detailed description of the Ph trifoliella male, based on recent terminology, as well as the data on its bionomics and habitat of the species are presented.