C. L. Smithhisler

Apple Fruit Infested with Codling Moth are More Attractive to Neonate Codling Moth Larvae and Possess Increased Amounts of (E,E)-α-Farnesene

Apple fruit artificially infested with codling moth larvae attracted significantly more neonate larvae of the codling moth, Cydia pomonella than uninfested fruit. A greater number of larvae responded to odor in an olfactometer from codling moth-infested cold-stored Red Delicious thinning apples than uninfested apples. Immature Granny Smith, Red Delicious, or Golden Delicious apples that were infested on the tree for five days by codling moth larvae were more attractive to neonate codling moth larvae than similar but uninfested fruit of the same varieties. Apples infested on the tree and sampled five days later also contained significantly greater amounts of the larval attractant (E,E)-α-farnesene, compared to uninfested apples. Other types of injury to apple fruit did not produce results similar to that from codling moth infestation, either in increased attractiveness to codling moth larvae or in increased quantities of (E,E)-α-farnesene. These results are consistent with the reported attractiveness of (E,E)-α-farnesene to neonate codling moth larvae.

Response of male codling moths (Cydia pomonella) to components of conspecific female sex pheromone glands in flight tunnel tests

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.

EFFICACY OF NONPHEROMONE COMMUNICATION DISRUPTANTS OF CODLING MOTH (Cydia pomonella): EFFECT OF PHEROMONE ISOMERS AND OF DISTANCE BETWEEN CALLING FEMALES AND DISPENSERS

Field tests comparing the ability of codlemone, (E,E)-8,10-dodecadien-1-ol, and isomers of codlemone to disrupt pheromonal communication of codling moth were carried out. In a pear orchard, four nonisomerizing, gray septa dispensers were placed in the upper canopy of each tree containing a trap baited with 10 virgin female codling moths. The dispensers were at trap height and 70 cm from the edge of each trap. Trap catches of released male codling moths in three test areas were compared simultaneously when trees in each of the test areas contained unbaited dispensers, dispensers with 1 mg of codlemone containing 1% isomers, and dispensers with 1 mg of a test communication disruptant. When the test disruptant was an equilibrium mixture of codlemone and its isomers (61% codlemone, 39% isomers), the percent communication disruption was 86.8% compared to 68.7% for codlemone (P < 0.001). When the disruptant was (E,Z)-8,10-dodecadien-1-ol (94%EZ, 3%EE), the percentage disruption was 86.4% compared to 62.7% for codlemone (P < 0.002). These results show that the previously reported superior disruptant potency (relative to codlemone) of compositions containing codlemone with a high percentage of isomers was not a result of the proximity of the dispensers to the traps. The percent disruption of compositions of codlemone with 10 and 20% isomers was also determined. A plot of percentage disruption versus logarithm of percentage of nonpheromone isomers in the mixture from 1% to 97% gave a straight line withR2=0.93.

Codling moth (Cydia pomonella): Disruptants of sex pheromonal communication.

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 gaver2 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.

Sabulodes caberata Guenée (Lepidoptera: Geometridae) components of its sex pheromone gland

A 6,9-nonadecadiene, (Z)-9-nonadecene, andn-nonadecane were identified in extracts of sex pheromone glands of femaleSabulodes caberata Guenée. Potential pheromonal activity of gland components was assessed by electroantennogram measurements of gas-chromatographic fractions of abdominal tip extracts. Chemical identification was based on gas chromatography and mass spectrometry of parent compounds, hydrogenation products, ozonolysis products, dimethyl disulfide adducts, and synthesis. The monoene was synthesized via coupling of alkyl and acetylenic intermediates. (Z,Z)-6,9-Nonadecadiene (Z6,Z9-19∶H) was synthesized from methyl linoleate via chain lengthening. SyntheticZ6,Z9-19∶H had the same retention times on polar and nonpolar capillary gas-chromatographic columns as the 6,9-nonadecadiene from the sex pheromone glands. In field testsZ6,Z9-19:H alone produced trap catch of maleS. caberata and addition of (Z)-9-nonadecene orn-nonadecane had no effect on trap catch.

Sex pheromone of cranberry fruitworm,Acrobasis vaccinii riley (Lepidoptera: Pyralidae).

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.

Apple ermine moth,Yponomeuta malinellus Zeller Two components of female sex pheromone gland highly effective in field trapping tests

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.

Sex pheromone of hickory shuckwormCydia caryana Development of an effective field Lure.

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.

Isolation and Identification of Female Sex Pheromone and Development of a Sex Attractant for Lacanobia subjuncta

Extracts of terminal abdominal segments of female Lacanobia subjuncta contained (Z)-11-hexadecenyl acetate, (Z)-11-hexadecenal, and (Z)-11-hexadecenol at a ratio of 1:0.2:0.02. (Z)-11-hexadecenyl acetate and (Z)-11-hexadecenal were most effective as a lure for trapping males when loaded in rubber septa at ratios near 3:1, respectively. The complete three-component blend was most effective as a lure for trapping males when loaded in rubber septa at a ratio of 3:1:0.08 for the acetate, aldehyde, and alcohol, respectively. In a comparison of doses of this three-component blend, greatest numbers of males were captured with 6.1 mg per rubber septum. These components, when loaded with an optimum ratio of components and suitable dose, should provide a useful lure for trapping Lacanobia subjuncta in agroeco-systems, permitting monitoring of distribution, emergence, and flight periods.

Mint root borer,Fumibotys fumalis (Guenee): Identification and field tests of female sex pheromone gland components.

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.