Field evaluation of female sex pheromone of the artichoke moth, Gortyna xanthenes

Field responses of Gortyna xanthenes (Germar) males to traps baited with different mixtures of the female sex pheromone components were evaluated in an artichoke field. Catches were compared to those obtained by virgin females and light traps. The best results were achieved by utilizing a mixture of 5 mg Z11-16:Ald + 0.15 mg Z9-16:Ald + 0.15 mg 16:Ald + 0.12 mg Z11-16:OH, which captured only G. xanthenes males 3–5 times more than light traps and ca two times more than one virgin female. Starting from the basic mixture Z11-16:Ald (89–92%) + Z9-16:Ald (2–4%), the addition of 16:Ald (2–4%) and of Z11-16:OH (2–3%) produced an increase of G. xanthenes and a decrease of H, armigera (Hb.) catches. The inhibitory action of Z11-16:OH towards H. armigera males was confirmed.

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Evaluation sur le terrain des constituants de la phéromone sexuelle de la noctuelle de l'artichaut (Gortyna xanthenes)

Résumé Dans un champ d'artichaut de la province de Salerno on a evalué la réponse des mâles de G. xanthenes à mélanges divers des constituants de la phéromone sexuelle produite par la femelle. Les meilleurs résultats ont été obtenus en employant un mélange de 5 mg Z11-16:Ald + 0.15 mg Z9-16:Ald + 0.15 mg 16:Ald + 0.12 mg Z11-16:OH, qui a capturé seulement les mâles de G. xanthenes en mesure 3–5 fois plus élevée que les pièges lumineux et ca. deux fois plus élevée que la femelle vierge. En partant du mélange base Z11-16:Ald (89–92%) + Z9-16:Ald (2–4%), l'addition de 16:Ald (2–4%) et de Z11-16:OH (2–3%) a causé un accroissement des captures de G. xanthenes et une diminution des captures de Heliothis armigera. Cela confirme l'action inhibitoire du Z11-16:OH à l'égard des males de H. armigera.

     

Field evaluation of female sex pheromone components of the cotton bollworm,Heliothis armigera

(Z)-11-hexadecenal and (Z)-9-hexadecenal were ineffective lures forH. armigera males unless combined. Attraction depended upon perception of a 90%–99% combination of (Z)-11-hexadecenal with 1%–10% (Z)-9-hexadecenal. Increasing the level of (Z)-9-hexadecenal in the mixture to 26.2% reduced catches. Adding 2.3% (Z)-7-hexadecenal to the mixture did not enhance or reduce attraction, while adding 8.7% (Z)-11-hexadecenol significantly reduced male catches. The combination of (Z)-11-hexadecenal and (Z)-9-hexadecenal was effective only when released from rubber dispensers but not from polyethylene vials. A load of 2 mg of the mixture on rubber dispensers effectively attracted males for at least 31 days. TheH. zea lure which contained all the pheromonal components of that species was also effective in attractingH. armigera males. TheH. virescens lure attracted significantly fewerH. armigera males than theH. zea lure.

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Résumé Les (Z)-11-hexadecenal et (Z)-9-hexadecenal sont des attractifs sexuels in efficaces pour les mâles deH. armigera. L'attraction dépend de la perception d'un mélange de 90 à 99% de (Z)-11-hexadecenal avec 1 à 10% (Z)-9-hexadecenal, L'augmentation jusqu'à 26,2% de la teneur en (Z)-9-hexadecenal réduit les captures. L'addition de 2,3% de (Z)-7-hexadecenal au mélange ne modifie pas l'attractivité, tandis que celle de 8,7% de (Z)-11-hexadecenol, réduit significativement les captures de mâles. Le mêlange de (Z)-11-hexadecenal et de (Z)-9-hexadecenal n'a été efficace qu'avec des diffuseurs en caoutchouc, par contre il a été sans effet à partir de récipients de polyéthylène. Une charge de 2 mg de mélange dans des diffuseurs en caoutchouc attire effectivement les mâles pendant ou moins 31 jours. L'attractif sexuel deH. zea qui contient tous les constituants de la phéromone de cette espèce attire aussi efficacement les mâles deH. armigera. Celui deH. virescens attire significativement moins de mâles deH. armigera que l'attractif sexuel deH. zea.

     

A sex pheromone component novel to the Geometridae identified fromEpirrita autumnata

(Z,Z,Z)-1,3,6,9-Heneicosatetraene was identified as a sex pheromone component ofEpirrita autumnata (Borkhausen), (Lepidoptera: Geometridae). Gas chromatography coupled with electroantennographic detection revealed one active peak from female pheromone gland extracts. The chemical identification of the compound was based on gas chromatography-mass spectrometry, chemical micro-reactions and unambiguous synthesis. In a field test, a rubber septum loaded with 3000 μg of this compound showed highest attraction of maleE. autumnata moths compared to lower doses and the control. The attraction of males to a 300 μg bait was equivalent to that obtained using live virgin females.     

Female sex pheromone of a lichen moth Eilema japonica (Arctiidae, Lithosiinae): Components and control of production

Seven candidates for components of the female sex pheromone of Eilema japonica (Arctiidae, Lithosiinae) were detected in an extract of pheromone glands with a gas chromatograph-electroantennographic detector. The compounds were identified as (Z,Z)-6,9-icosadiene (D20), (Z,Z)-6,9-henicosadiene (D21), (Z,Z,Z)-3,6,9-henicosatriene (T21), (Z,Z)-6,9-docosadiene (D22), (Z,Z,Z)-3,6,9-docosatriene (T22), (Z,Z)-6,9-tricosadiene (D23), and (Z,Z,Z)-3,6,9-tricosatriene (T23). Assays using synthetic lures in a wind tunnel showed that D21 (proportion, 0.39), T21 (0.08), D22 (0.27), and T22 (0.26) are important for evoking full behavioral responses from the males. Titers of the pheromone components did not show clear temporal fluctuations. Moreover, decapitation of the female moth had no effect on the titers of pheromone components in the pheromone gland, suggesting that cephalic endocrine factors such as pheromone biosynthesis activating neuropeptide (PBAN) are not involved in the control of pheromone biosynthesis in this species.     

A Selective Method of Estimation of Bacitracin in the Presence of Other Antibiotics and Growth Factors

The plum cankerworm moth, Cystidia couaggaria couaggaria (Geometridae: Ennominae), is a defoliator of Chinese plum trees (Prunus mume). The pheromone components of the female were analyzed by gas chromatography (GC) with an electro-antennographic (EAG) detector and GC coupled with mass spectrometry. The crude pheromone extract included several EAG-active components, i.e., trienyl, dienyl, and saturated hydrocarbons, with a C₂₁–C₂₅ straight chain. The characteristic mass spectra indicated the unsaturated hydrocarbons to be (3Z,6Z,9Z)-3,6,9-trienes and (6Z,9Z)-6,9-dienes. In the fields, mixtures of the synthetic C₂₁ and C₂₃ trienes in a ratio of 2:3 and 1:4 successfully attracted males of this diurnal species during daytime. While the male antennae responded to the C₂₅ triene and saturated hydrocarbons, their synergistic effects were not observed on the male attraction in the fields. Addition of the C₂₁ diene interestingly inhibited the activity of the triene mixture. Males of Cystidia truncangulata, a sympatric diurnal congener of C. c. couaggaria, showed similar EAG responses to the unsaturated hydrocarbons, but no C. truncangulata males were attracted by the lures tested for C. c. couaggaria males, indicating that the identified hydrocarbons comprised the species-specific pheromone of C. c. couaggaria females.     

Identification of components of the female sex pheromone of the potato tuber moth, Scrobipalpopsis solanivora

The sex pheromone produced by virgin female S. solanivora moths has been shown to contain (E)-3-dodecenyl acetate with approximately 2% of the Z isomer by electroantennography and gas chromatography. In the field, traps baited with (E)-3-dodecenyl acetate alone or in combination with 1% or 2% of the Z isomer caught at least as many male S. solanivora moths as those baited with virgin female moths, and there was some evidence that addition of 5% of the Z isomer reduced catches.

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Résumé S. solanivora est l'un des plus importants lépidoptères détruisant les pommes de terre en Amérique Centrale. L'analyse par chromatographie en phase gazeuse (GC) des produits obtenus par lavage de l'ovipositeur de femelles vierges, associée à des électro-anténnogrammes (EAG) a révélé un composé actif unique en EAG. Les durées de rétention pour ce constituant correspondaient à celles des acétates monoinsaturés à 12 carbones, et les analyses sur colonne GC liées avec une phase liquide cristal ont montré un pic principal correspondant à l'acétate (E)-3-dodécénul et un pic secondaire, correspondant à l'isomère Z, et au niveau de 2,5% du pic principal. L'acétate dodécyl a aussi été décelé en quantités variables, approximativement 10% du pic principal.Dans la nature, des pièges contenant de l'acétate (E)-3-dodécényl, seul ou mélangé avec 1 ou 2% de l'isomère Z, ont capturé autant des mâles de S. solanivora que des pièges contenant des femelles vierges, et certaines indications montrent que l'addition de 5% de l'isomère Z réduit les captures.

     

Conformational Changes of αs-Casein by Heating

Conformational changes of α_s-casein by heating were investigated by measuring ultraviolet difference spectra. The ultraviolet difference spectra at elevated temperature against 5.5°C were measured in various ionic strengths and pHs. Thermal effects of the difference spectra were cancelled by comparing with the spectra of model compounds such as lysozyme and ribonuclease, and the blue shift of α_s-casein spectra was observed at above 30°C in these all experimental conditions. This shift was considered to mean unfolding of the α_s-casein molecule. The aggregation of α_s-casein was observed above ionic strength of 0.4 by heating. These heat-induced changes were reversible until the aggregation was observed.     

Sex pheromone dosage and blend specificity of response by oriental fruit moth males

The sex pheromone-mediated responses of male oriental fruit moths, Grapholitha molesta (Busck), to an array of blends and dosages of Z8-12Ac and E8-12:Ac, were analyzed. Males exhibited sustained upwind flight resulting in source location only to intermediate blends and dosages. This optimal range of treatments appeared to be bounded by dosages too low or too high to result in significant attraction (net within-plume displacement toward the source), the higher concentrations causing arrestment (no net within-plume displacement) at some distance from the source. Similar results were obtained in field-trapping studies with the same treatments, except that the optimal dosages were moved up about 10-fold. Increased turning and decreased linear velocity could account for arrestment with increasing amounts of the (E) isomer in high dosages and high (E)/(Z) ratio blends.

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Zusammenfassung Das Sexualverhalten männlicher Falter des Pfirsichtriebwicklers, Grapholitha molesta (Busck), gegenüber verschiedenen Dosierungen und Mischungen von (Z)-8- und (E)-8-Dodecenylacetat wurde untersucht. Ein stetiger Aufwindflug, der zum Auffinden der Duftquelle führte, konnte nur im mittleren Dosierungs- und Mischungsbereich beobachtet werden. Ausserhalb dieses Optimums war die Dosierung offenbar entweder zu hoch oder zu niedrig, um eine deutliche Anlockung, d.h. einen gerichteten Flug innerhalb der Duftfahne zu bewirken; bei hoher Konzentration näherten sich die Tiere der Quelle nur auf bestimmte Distanz (arrestment). Freilandversuche mit Fallen führten zu ähnlichen Ergebnissen, nur dass dort das Dosierungsoptimum bei ca. zehnmal höheren Werten lag als in den Versuchen im Windkanal. Der bei hohen Mengen an E-Isomer (hohe Dosis oder hohes E/Z-verhältnis) beobachtete Arrestment-Effekt könnte auf Erhöhung der Drehbewegungen oder Verringerung der Fluggeschwindigkeit zurückzuführen sein.

     

Electrophysiological and behavioural evidence for a fourth sex pheromone component in the turnip moth, Agrotis segetum

Abstract. In addition to the pheromone components (Z)-5-decenyl, (Z)-7-dodecenyl and (Z)-9-tetradecenyl acetate (Z5-10:OAc, Z7-12:OAc and Z9-14:OAc), it has previously been shown that the sex pheromone gland of the turnip moth, Agrotis segetum (Lepidoptera: Noctuidae Schiff) contains 10:OAc, 12:OAc, Z5-12:OAc, Z9-12:OAc, 11–12:OAc, Z5-14:OAc, Z7-14:OAc and Z11-16:OAc. To find out whether any of these additional compounds is involved in the sex pheromone communication in A. segetum, a comprehensive electro-physiological and behavioural investigation was conducted. Single-sensillum recordings on male antennae revealed three subtypes of sensilla among the previously so-called Z5-10:OAc sensilla. One subtype was identified having one receptor neurone (A) that responded to Z5-10:OAc with a large spike amplitude and another neurone (B) that responded to (Z)-5-decenol (Z5-10:OH) with a small spike amplitude. In another subtype the B neurone responded to Z5-12:OAc and sometimes also to 27-12:OAc and 10:OAc, in addition to responding to Z5-10:OH. In a third subtype the A neurone responded to all acetates identified from the female pheromone gland, whereas the small spike amplitude neurone was tuned to Z5-10:OH. A flight tunnel assay showed that blends composed of nine, eight or seven compounds were equivalent to the previously identified three-component pheromone blend in eliciting male behavioural responses. In field trapping tests, blends of eleven, nine or seven compounds did, however, catch significantly more moths than the three-component blend. Further assays showed that only 25- 12:OAc could significantly increase the catch numbers when added to the three-component blend, and thus qualified as a fourth pheromone component in A. segerum. The behavioural significance of additional female-produced acetates — for which males possess antennal receptors — is suggested, but may be impossible to confirm because of ‘diminishing returns’ when trying to refine a multicomponent pheromone further.     

Identification of novel sex pheromone components from a tussock moth, Euproctis pulverea

Two EAG-active compounds were found in the solvent extract of abdominal tips of virgin females of the tussock moth Euproctis pulverea (Leech) (Lepidoptera: Lymantriidae), and identified as (Z,Z,Z)-11,14,17-icosatrienyl isobutyrate and (Z,Z,Z)-11,14,17-icosatrienyl 4-methylvalerate at 190 and 80 ng female^–1, respectively, by means of GC-MS analyses and chemical derivatization. Esters of n-butyric acid, n-valeric acid, n-hexanoic acid and a methylheptanoic acid were also found at 3, 2, 0.4 and 9 ng female^–1 as minor EAG-inactive compounds. Two active compounds were also detected in the hexane extract of female anal tufts at 17 and 6 ng female^–1, respectively. In Okinawa, the binary blend of the synthetic compounds attracted male moths to the sticky traps, but single compounds did not. The significance of these findings in relation to parasitism by Telenomus euproctidis (Hymenoptera: Scelionidae) is discussed.     

Correlation of housefly sex pheromone production with ovarian development

Pheromone production in the housefly was monitored during oögenesis and in ovariectomized insects by gas-liquid chromatography (GLC) and radio-GLC. The presence of vitellogenic ovaries was required for the initiation of (Z)-9-tricosene (muscalure), (Z)-9,10-epoxytricosane and (Z)-14-tricosen-10-one synthesis. Methylalkane synthesis was enhanced by developing ovaries. Insects ovariectomized within 12 hr after emergence produced no detectable amounts of (Z)-9-tricosene, C₂₃ epoxide nor C₂₃ ketone and synthesized less methylalkanes than the controls. This effect was reversed by ovary implants. When flies were ovariectomized after oviposition, synthesis of (Z)-9-tricosene, C₂₃ epoxide and C₂₃ ketone continued. Thus, initiation of the synthesis of these C₂₃ pheromone compounds required a vitellogenic ovary, but the ovary was not required to maintain synthesis.     

Components of the female sex pheromone of the yellow stem borer, Scirpophaga incertulas

Ovipositor washings and volatiles from virgin female Scirpophaga incertulas (Walker) (Lepidoptera: Pyralidae) were analysed by gas chromatography (GC) linked to electroantennography (EAG). Two EAG responses were observed at retention times consistent with those of monounsaturated 16-carbon aldehydes and monounsaturated 16-carbon alcohols. Analysis of ovipositor washings on high-resolution, capillary GC columns showed peaks which cochromatographed with (Z)-11-hexadecenal, (Z)-9-hexadecenal, (Z)-11-hexadecen-1-ol and hexadecanal. EAG responses of male S. incertulas to synthetic hexadecenal isomers were greatest for the (Z)-11 and (Z)-11 isomers. Field tests in the Philippines showed that traps baited with a mixture of (Z)-11-hexadecenal and (Z)-9-hexadecenal in the naturally occurring 3:1 ratio caught significantly more male S. incertulas moths than those baited with a virgin female moth. Addition of (Z)-11-hexadecen-1-ol to this mixture reduced trap catches.

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Résumé Des produits provenant du lavage d l'ovipositeur et des substances volatiles de femelles vierges de S. incertulas Walker (Lep.: Pyralidae) ont été examinées en chromatographie en phase gazeuse (GC) avecélectroantennogramme simultané(EAG). Deux réponses EAG ont été enregistrées à des temps de rétention correspondant à ceux des aldéhydes monoinsaturés 16 carbones et des alcools monoinsaturés 16 carbones. L'analyse des produits provenant du lavage de l'ovipositeur en colonnes GC capillaires à haute résolution a donné des pics correspondant aux (Z)-11-hexadécenal, (Z)-9-hexadécenal, (Z)-11-hexadecen-1-ol et à l'hexadecanal. Les réponses EAG de mâles de S. incertulas aux isomères synthétiques d'hexadécenal étaient plus intenses pour les isomères (Z)-11 et (E)-11. Des essais en champ aux Philippines ont montré que les pièges contenant un mélange de (Z)-11-hexadécenal et de (Z)-9-hexadécenal dans le rapport natural 3/ 1 capturaient plus de mâles de S. incertulas que ceux contenant une femelle vierge. L'addition au mélange de (Z)-11-hexadecen-1-ol réduit les captures.