H. Arn

The Electroantennographic Detector — a Selective and Sensitive Tool in the Gas Chromatographic Analysis of Insect Pheromones

Abstract A gas chromatographic detector is described which uses an insect antenna as a sensing element and permits the continuous monitoring of pheromones and other compounds with olfactory activity. In high-resolution gas chromatography allowing separations of positional and geometrical isomers, the electroantennographic detector gives precise information on the retention times of active compounds and permits the analysis of insect pheromones with exceedingly small amounts of material.

Field attraction ofAgrotis segetum males in four european countries to mixtures containing three homologous acetates

Abstract(Z)-5-Decenyl, (Z)-7-dodecenyl, and (Z)-9-tetradecenyl acetate were tested as single compounds and blends for field attraction to the turnip moth in Denmark, France, Hungary, and Switzerland. Best attraction was obtained when all three components were present. Attractants for other noctuids are described, e.g.,Meristis trigrammica, Hoplodrina alsines, Erastria trabealis, Euxoa nigricans, Axylia putris, andAutographa gamma, which were caught with some of the components and their blends.

Multicomponent Sex Pheromone in Agrotis segetum: Preliminary Analysis and Field Evaluation

Abdominal rinses of calling females of the turnip moth, Agrotis segetum, were analyzed by capillary gas chromatography combined with flame ionization detection, electroantennographic detection and mass spectrometry. Traces of a compound showing the retention time and high elec- trophysiological activity of (Z)-5-decenyl acetate could be detected only by electroantennography. In addition, (Z)-7-dodecenyl acetate, (Z)-9-dodecenyl acetate, dodecyl acetate and a compound resembling (E)-5-dodecenyl acetate were found. A mixture of these 5 compounds was as attractive in the field as were virgin females, while (Z)-8-dodecenyl acetate, which was also found in the female, was a strong inhibitor. Wind tunnel and field experiments indicate that (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate and probably (Z)-9-dodecenyl acetate are essential for attraction.

Notizen: Sex Pheromone of Lobesia botrana : (E,Z)-7,9-Dodecadienyl Acetate in the Female Grape Vine Moth

Mass spectrometry in combination with high resolution gas chromatography were used to demonstrate the presence of (E,Z) -7,9-dodecadienyl acetate in Lobesia botrana females. The data indicate that this male attractant is a natural sex pheromone of the grapevine moth.

Analysis of insect pheromones by quadrupole mass fragmentography and high-resolution gas chromatography

A sensitive technique is described for the analysis of insect pheromones. Insect extracts are separated into fractions by column chromatography and are analyzed directly by quadrupole mass fragmentography on high-resolution glass capillary columns and by mass spectrometry. Applications are illustrated with two important pests. In the codling moth, trans-8, trans-10-dodecadien-1-ol was found to be present at a level of 3.5 ng per female, and in the European grapevine moth trans-7, cis-9-dodecadienyl acetate at a level of 1.6 ng. Both compounds appear to be present in high isomeric purity in the female insect and are absent in the corresponding males.

Sex pheromone ofAdoxophyes orana: Additional components and variability in ratio of (Z)-9- and (Z)-11-tetradecenyl acetate

Twelve products related to the sex pheromone main components (Z)-9- and (Z)-11-tetradecenyl acetate (Z9–14∶Ac andZ11–14∶Ac, respectively), were identified in female pheromone gland extracts of the laboratory-reared summerfruit tortrix moth,Adoxophyes orana F.v R. These are the geometric isomers and the alcohols of the main components, (Z)-9-dodecenyl acetate, (Z)-11-hexadecenyl acetate, and saturated acetates of 12–22 carbons. The ratio ofZ9–14∶Ac toZ11–14∶Ac in individuals varied from 3.5∶1 to 11∶1 with an average of 6.2; their total added up to 462 ng/female with an average of 182 ng for 2- to 7-day-old individuals. No qualitative or quantitative differences were observed between laboratory and field insects.Z9–14∶Ac,Z11–14∶Ac and the corresponding alcohols were also found in female effluvia. Addition of either of the two alcohols to a blend of the two acetates augmented trap catch in the field. The same was true for (Z)-9,(E)-12-tetradecadienyl acetate which was not detected in gland extracts.

Sex pheromone ofGrapholita funebrana occurrence ofZ-8- andZ-10-Tetradecenyl acetate as secondary components.

Z-8-Dodecenyl acetate (Z8–12∶Ac),E-8-dodecenyl acetate (E8–12∶Ac),Z-8-tetradecenyl acetate (Z8–14∶Ac),Z-10-tetradecenyl acetate (Z10–14∶Ac), andZ-8-dodecen-1-ol (Z8–12∶OH) were identified in the proportions 100∶1∶30∶5∶2 in female sex gland extracts ofGrapholita funebrana, accompanied by saturated acetates from 12 to 20 carbons with tetradecyl acetate predominating.Z10–14∶Ac has not previously been described as a lepidopteran sex pheromone component. Best attraction of males is obtained withZ8–12∶Ac in the presence of a higher proportion ofE8–12∶Ac than in the female. Inclusion of the 14-carbon acetates did not augmentG. funebrana catches but inhibitedG. molesta. On the other hand, addition ofZ8–12∶OH at the level optimal forG. molesta reduced attraction ofG. funebrana.

Identification of sex pheromone components of redbacked cutworm,Euxoa ochrogaster, and modification of sex attractant blend for adult males

Pheromone washes from calling female moths of redbacked cutworm,Euxoa ochrogaster (Guenée), contained the following acetates that are structurally similar to those of known lepidopteran pheromones (%): decanyl (8.7), dodecanyl (8.5), (E)-5-dodecenyl (3.3), (Z)-5-dodecenyl (76.4), (Z)-7-dodecenyl (3.1), and (Z)-9-dodecenyl (trace<0.5%). This is the first time that (Z)-5-dodecenyl acetate has been identified as a pheromone component. Three types of specific receptor cells were found in the male antennae, and they responded to (Z)-5-decenyl acetate, (Z)-5- and (Z)-7-dodecenyl acetates, respectively. Strong electroantennographic detector responses were also recorded for these three acetates and for (Z)-5-undecenyl acetate. The evidence for the presence of (Z)-5-decenyl acetate in the pheromone washes was inconclusive. The presence of (Z)-7- and the absence of (Z)-8-dodecenyl acetates were confirmed by a special electroantennographic detector technique in which the detector antennae were from males of other species that were known to have strong responses to these acetates. This is a very useful technique. Field results show that low concentrations (0.1–1.3%) of (Z)-5-decenyl acetate were synergistic when tested in a previously reported blend, but 6% was inhibitory. Similarly, (Z)-7-dodecenyl acetate at 2% or less may be essential for the attraction of males, but in previous tests at 14% it also was inhibitory. Species-specific attractant blends for redbacked cutworm males are described.

Abraxas grossulariata L. (Lepidoptera: Geometridae): Identification of (3Z,6Z,9Z)-3,6,9-heptadecatriene and (6Z,9Z)-6,9-cis-3,4-epoxyheptadecadiene in the female sex pheromone

Abstract(3Z,6Z,9Z)-3,6,9-Heptadecatriene and (6Z,9Z)-6,9-cis-3,4-epoxyheptadecadiene have been identified in female sex pheromone gland extracts ofAbraxas grossulariata L. (Lepidoptera: Geometridae). The compounds were detected by gas chromatography with electroantennographic detection (GC-EAD) and identified by GC-mass spectrometry (GC-MS). The amounts of hydrocarbon and epoxide were 0.13 and 0.42 ng/female, respectively. These identifications were confirmed by synthesis; the absolute configuration of the epoxide remains to be determined. Another isomeric epoxide, (3Z,6Z)-3,6-cis-9,10-epoxyheptadecadiene, was tentatively identified in small amounts (0.04 ng/female). Racemic (6Z,9Z)-6,9-cis-3,4-epoxyheptadecadiene elicited the largest electroantennogram response within a series of heptadecadiene and nonadecadiene monoepoxides and the corresponding trienic hydrocarbons and, in field tests, attracted maleA. grossulariata into traps. Addition of 10% (3Z,6Z,9Z)-3,6,9-heptadecatriene to this epoxide enhanced attractiveness; addition of (3Z,6Z)-3,6-cis-9,10-epoxyheptadecadiene had no effect at low proportions while higher proportions caused a reduction in the numbers of males caught.

Identification of 4 sex pheromone components isolated from calling females of Mamestra brassicae.

Abstract Evidence obtained by glass capillary gas chromatography coupled to an electroantennographic detector or a mass spectrometer confirmed that Z-11-hexadecenyl acetate is the major component in the pheromone gland washes of calling Mamestra brassicae female moths. Three other components were identified, tetradecanyl acetate, hexadecanyl acetate and E-11-hexadecenyl acetate; but none of these had obvious synergistic effects in attracting males in field tests. The attraction of males to Z -11-hexadecenyl acetate was inhibited by 0.1% Z -11-hexadecenol or 1% Z-9- tetradecenyl acetate.