H G Davis’s research while affiliated with United States Department of Agriculture and other places

When the nine identified components in the effluvium of calling female codling moths were compared to pure synthetic (E,E)-8,10-dodecadien-1-ol in flight-tunnel tests, equal responses were obtained over a concentration range of 300-fold. When synthetic (E,E)-8,10-dodecadien-1-ol was compared to extract of female sex pheromone glands by a male wing-flutter bioassay, or in flight-tunnel tests, equal responses were obtained over a concentration range of 1000-fold. The sum total of these and previous studies indicate that the codling moth sex pheromone consists of only one component.

The following compounds and (approximate ratios) were identified in sex pheromone gland extracts of femaleAcrobasis vaccinii Riley by comparison of gas chromatography-mass spectrometric traces with those of synthetic standards: (E,Z)-, (Z,E)-, (Z,Z), and (E,E)-8, 10-pentadecadien-l-ol acetates (100:1:2:12), a dodecen-l-ol acetate (8), (Z)-8-, (Z)-9-, and (E)-9-pentadecen-l-ol acetates (3:23:4), two heptadecen-l-ol acetates (4:4), tetradecyl, pentadecyl, hexadecyl, and heptadecyl acetates (3:15:10:8), dodecan-l-ol (6), tetradecan-l-ol (5), and hexadecan-l-ol (23). The amount of (E,Z)-8, 10-pentadecadien-l-ol acetate (E8,Z10-15:Ac) in the extract was about 0.5 ng/female. Electroantennographic analysis of gas chromatographic fractions of female sex pheromone gland extract showed that the fraction containingE8,Z10-15:Ac elicited the greatest response. Alone,E8,Z10-15:Ac failed to elicit upwind flight of males in flight-tunnel tests, and traps baited with it did not catch males in field experiments. WhenE8,Z10-15:Ac was combined with (E)-9-pentadecen-l-ol acetate (100:4), male upwind flight response in flight-tunnel tests was equivalent to those obtained with extract of female sex pheromone glands (synthetic, 62%; natural, 51%), but the percent of males flying upwind that contacted the source was lower (synthetic, 47%; natural, 88%). The lower percent of source contact elicited by the synthetic pheromone could be a result of the difference in isomer ratios of 8,10-15:Ac in the natural and synthetic pheromone or could indicate that the synthetic pheromone is incomplete. Traps baited with the 100:4 combination caught large numbers of males in field experiments.

In a small section of an apple orchard, six traps were placed each in control and test areas and baited with live virgin female codling moths. Gray elastomer septa were used to dispense communication disruptants around the traps. Dyed male codling moths were released in control and test areas, and the numbers of males captured in control and test traps were compared. In 1991, linear regression curves of percent communication disruption versus logarithm of dose were obtained for three compositions: (E,E)-8,10-dodecadien-1-ol, codlemone (1); codlemone + dodecan-1-ol + tetradecan-1-ol (2); and an equilibrium mixture of the four isomers of 8,10-dodecadien-1-ol (30, (61%EE, 14%ZE, 20%EZ, and 5%ZZ). All three regressions gaver 2 values greater than 0.90. At the 95% confidence limits, slopes and intercepts of compositions 1 and 2 were equivalent, and different from that of composition 3, which produced the greatest percentages of disruption at all doses. In 1992, five treatments were compared at a single dose: 1, 3, none (4), (Z,E)-8,10-dodecadien-1-ol (5), (E,Z)-8,10-dodecadien-1-ol (6). Compositions 5 and 6 gave the greatest and similar percentages of disruption and were different from codlemone (1) and 4 (95% confidence), but not from composition 3. Communication disruption produced by composition 3 was greater than (codlemone), which was greater than 4.

In flight tunnel tests, the percentages of oriented upwind flights of male codling moths culminating in contacting a source of different compositions of female sex pheromone gland components were determined over a dosage range of 0.1-100,000Μg. The following compositions were tested: (1) (E,E)-8,10-dodecadien-1-ol of 99.7% isomeric purity; (2) 1 + dodecanl-ol + tetradecan-1-ol; (3) 2 + decan-1-ol + (E)-9-dodecen-1-ol; and (4) an equilibrium mixture of 8,10-dodecadien-1-ol isomers (61%EE, 5%ZZ, 14%ZE, and 20%EZ). The ratios of the components in compositions 2 and 3 were chosen to produce vapor ratios equal to the natural ratios found in the female effluvium by Arn and coworkers. As the dose of composition 1 was increased from 0.1 to 10Μg, response increased from 0 to about 80% and then was approximately constant from 10 to 300Μg. Over the range 0.1-300Μg, the percentage of males contacting the septum was virtually the same as the percentage flying upwind. From 300 to 100,000Μg, the percentage of males flying upwind and contacting the source steadily decreased from about 80 to 0%. The male responses to compositions 2 and 3 were virtually identical to the response to 1. These results indicate, contrary to published reports, that dodecan-1-ol and tetradecan-1-ol in combination with 1 do not increase the responses of the behavioral modes determining degree of attractancy and disruption of sexual communication over that of 1 alone. These results also show that decan-1-ol and (E)-9-dodecen-1-ol do not enhance response in the five-component mixture. The response to composition 4 increased from 0% at a dose of 0.3Μg to 26% at a dose of 30Μg and then decreased to 0% at a dose of 3000Μg. Thus, the inhibiting effect of the isomers on response was greater at the higher doses.

Electroantennogram profiles of saturated and monounsaturated 12-, 14-, and 16-carbon acetates, and 12- and 14-carbon alcohols implicated (Z)-9-tetradecen-1-ol acetate (Z9-14: Ac) as a component of the female sex pheromone ofHulstia undulatella (Clemens). Gas chromatography-mass spectrometric analysis of extract of the female sex pheromone glands showed the presence of Z9-14:Ac (8.5 ng/female), (Z)-9-tetradecen-1-ol (Z9-14:OH), and (Z)-11-hexadecen-1-ol acetate (Z11-16:Ac) in a ratio of 100∶4∶21, respectively. In tests in sugar beet fields, Z9-14:Ac alone produced some trap catch. Addition of Z9-14: OH did not increase catch while addition of Z11-16:Ac eliminated catch, but addition of both Z9-14:OH and Z11-16: Ac increased catch sevenfold. A combination of Z9-14: OH and Z11-16: Ac without Z9-14: Ac did not produce trap catch. A lure of 200 μg Z9-14:Ac+16 μg Z9-14:OH+42 μg Z11-16:Ac is suggested for use in monitoring traps.

Compounds identified in sex pheromone gland extracts of femaleFumibotys fumalis (Guenee) consisted of (E,E)-10,12-tetradecadienyi acetate, (Z)-11-tetradecenyl acetate, (E)-11-tetradecenyl acetate, and (Z)-9-tetradecenyl acetate in a ratio of 100:18: 8:4, respectively. The compounds were identified by electroantennographic, gas Chromatographic, mass spectrometric, and chemical derivatization procedures. In mint fields synthetic components in gray elastomeric septa at ratios found in the sex pheromone gland and at doses of 3 or 10 mg of the diene produced trap catch comparable to traps baited with three females.

Extracts of the sex pheromone glands of femaleCydia caryana were evaluated by electroantennography and gas chromatography-mass spectrometry. These studies suggested the following compounds were potential sex pheromone components: (Z)-8- and/or (E)-9-dodecenyl acetate (50 pg/female), dodecyl acetate (40 pg/female), and (E, E)-8,10-dodecadienyl acetate (25 pg/female). In field tests only the diene produced trap catch, and when the other components were added to the diene, trap catch was not increased. When the diene was formulated in red natural rubber septa, only transient and low catches were obtained, but when gray halobutyl isoprene elastomeric septa were used, high and consistent catches were obtained for eight weeks. Catches depended on the ratio of (E, E)-8,10 to (E, Z)-8,10 isomers. High catches were obtained for anEE toEZ ratio of 100 : 0.6, and insignificant catches were obtained when the ratio was 100 : 3. Equivalent catches were obtained for dosages of 50, 100, and 200 µg/septum.

When electroantennographic responses of maleYponomeuta malinellus Zeller to model compounds were determined at dosages of 0.3-30 ng, the strongest responses were obtained from (Z)-9-dodecen-1-ol acetate (Z9-12∶Ac). Also, strong responses were obtained from (Z)-11-tetradecenal (Z11-14∶A1) and (Z)-11-tetradecen-1-ol (Zl1-14∶OH). At a dosage of 0.3 ng,Z11-14∶A1 produced a stronger response thanZ11-14∶OH, while at a dosage of 30 ng,Z11-14∶OH andZ11-14∶A1 produced equal responses. Gas chromatographic and mass spectral analysis of extracts of female sex pheromone glands showed the presence ofZ9-12∶Ac, tetradecan-1-ol (14∶OH), (E)-11-tetradecen-1-ol (E11-14∶OH),Z11-14∶OH, hexadecan-1-ol, and hexadecan-1-ol acetate in a ratio of 0.6∶200∶37∶100∶140∶35. In field tests,Z9-12∶Ac andZ11-14∶OH together were required for trap catch, and addition ofZ11-14∶A1,E11-14∶OH, 14∶OH, or (Z)-11-tetradecen-1-ol acetate did not increase catch. Ratios in rubber septa of 0.5∶99.5 to 1.5∶98.5 (Z9-12∶ Ac/Z11-14∶OH) captured the most males and captures were statistically equivalent for dosages of 10-1000 μg/rubber septum. Traps baited with the synthetic lure produced better catches than those baited with females.

Electroantennogram (EAG) measurements of male Cydia caryana moth antennal olfactory response to monounsaturated 12 and 14 carbon alcohols and acetates indicated that the ( E )‐8‐, ( E )‐10‐ conjugated double bond system of a dodecadien‐1‐ol acetate is a critical chemical structural component of the C. caryana sex pheromone. Additionally, EAG measurements implicated ( E )‐8‐dodecen‐1‐ol acetate, ( Z )‐8‐dodecen‐1‐ol acetate, ( Z )‐9‐dodecen‐1‐ol acetate and ( Z )‐12‐tetradecen‐1‐ol as potential minor pheromonal components. An EAG dosage‐response study suggested that there were at least two heterologous populations of pheromone acceptors. Behavioral analysis of male moth response in a flight tunnel to compounds which evoked the stronger EAG responses suggested that ( E,E )‐8,10‐dodecadien‐1‐ol acetate and ( Z )‐9‐dodecen‐1‐ol acetate resemble or are C. caryana sex pheromonal components, while ( Z )‐8‐dodecen‐1‐ol acetate and ( E )‐10‐dodecen‐1‐ol acetate are either parapheromones or are minor pheromone components. Behavioral significance of ( Z )‐12‐tetradecen‐1‐ol was difficult to interpret in the flight tunnel. RÉSUMÉ Etude par électroantennographie et avec tunnel de vol des constituants potentiels des phéromones sexuelles Cydia caryana ( Lépidoptère, Tortricidae, Olethreutinae ). Les réponses olfactives antennaires de Cydia caryana , mesurées par électroantennogrammes (EAG), aux alcools et acétates à carbones monounsaturés en positions 12 et 14, ont montré que le système conjugué de double liaison, ( E )‐8‐, ( E )‐10‐ dudodecadien‐1‐ol acétate constitue un composé chimique strutural critique de la phéromone sexuelle de C. caryana. De plus, les acétates: ( E )‐8‐dodecen‐1‐ol,( Z )‐8‐dodecen‐1‐ol,( Z )‐9‐dodecen‐1‐ol, et le ( Z )‐12‐tetradecen‐1‐ol, se sont révélés en AEG comme des composés secondaires de la phéromone. L'étude par AEG de la relation dose‐réponse a conduit à l'hypothèse de deux catégories de populations de récepteurs de phéromones. L'analyse comportementale des résponses des papillons mâles dans le tunnel de vol aux composés qui ont provoqués les plus forts AEG, on fait estimer que les acétates ( E,E )‐8,10‐dodécadien‐1‐ol et ( Z )‐9‐dodecen‐l***‐ol ressemblent (ou sont) les constituants de la phéromone sexuelle de C. caryana; tandis que les ( Z )‐8‐dodecen‐l***‐ol et ( E )‐10‐dodecen‐l***‐ol sont, soit des paraphéromones, soit des constituants mineurs de la phéromone. La signification biologique du ( Z )‐12‐tétradécen‐l***‐ol a été difficile à interprêter avec les expériences en tunnel de vol.

Electroantennogram (EAG) responses of maleRhopobota naevana (Hübner), the blackheaded fireworm, to all of the monoene straightchain 12- and 14-carbon alcohols and acetates implicated (Z)-11-tetradecenl-1-ol (Z11-14∶OH) and its acetate (Z11-14∶Ac) as sex pheromone components.Z11-14∶Ac produced the strongest EAG response of all compounds tested. Gas chromatography-mass spectrometry (GC-MS) analysis of extract of female sex pheromone glands (SPG) confirmed the presence ofZ11-14∶OH (125 pg/female) andZ11-14∶Ac (600 pg/female) (all other monoenes had different retention times). In field tests, traps baited withZ11-14∶OH alone captured males, but traps baited withZ11-14∶Ac alone did not. Traps baited with a combination ofZ11-14∶OH andZ11-14∶Ac in various ratios did not produce better trap catches thanZ11-14∶OH alone. (Z)-9-Dodecen-1-ol acetate (Z9-12∶Ac), reported by others to be a field attractant, did not produce trap catch in our tests, but in combination withZ11-14∶ OH (98∶2 in septa corresponding to 95:5 in vapor,Z11-14∶OH toZ9-12∶AC) produced a sevenfold increase in catch overZ11-14∶OH alone. IfZ9-12∶AC had been present in extract of SPG at 2-5% ofZ11-14∶OH, it would not have been detected in our GC-MS experiment.