B. A. Bierl-Leonhardt

Sex pheromone chemistry of the female tobacco budworm moth, Heliothis virescens.

Abstract(Z)-11 -Hexadecenal (77–91%), (Z)-7-hexadecenal (0.1–2%), (Z)-9-hexadecenal (0.3–2%), hexadecanal (3–19%), (Z)-11-hexadecen-1-ol (1–5%), tetradecanal (1–3%), and (Z)-9-tetradecenal (1–3%) were identified from the heptane washes of the ovipositor of femaleHeliothis virescens (F.) females. In field bioassays, a 152-μg mixture of these seven compounds deployed in an insect trap exceeded the attractiveness of 4 virgin femaleH. virescens for males and was 5–6 times more attractive than a mixture of (Z)-1 1-hexadecenal and (Z)-9-tetradecenal (virelure) that was previously reported as the sex pheromone of the species. Four of the seven compounds produced byH. virescens females are also produced byH. zea (Boddie). Specificity of pheromonal signals among the two species is ostensibly dependent upon one or more of the three additional compounds [tetradecanal, (Z)-9-tetradecenal, and (Z)-1 1-hexadecen-1-ol] produced by femaleH. virescens.

Sex pheromone chemistry of female corn earworm moth, Heliothis zea.

Glass open-tubular capillary Chromatographic and combined glass open-tubular capillary chromatographic-mass spectrometric analyses of ovipositor washes of femaleHeliothis zea, chemical characterization, chemical synthesis, and laboratory and field bioassays showed that the ovipositor wash of the species is made up of 90–95% (Z)-11-hexadecenal, 1–2% (Z)-9-hexadecenal, 0.4–2% (Z)-7-hexadecenal, and 2–7% hexadecanal. Stimuli containing a binary mixture of (Z)-11-hexadecenal and (Z)-9-hexadecenal or the binary mixture in combination with any of the other aldehydes identified from the females elicited intense attraction and close-range precopulatory reactions fromH. zea males.

Trace chemicals: the essence of sexual communication systems in heliothis species.

Analysis of heptane-soluble compounds from ovipositors of Heliothis zea and Heliothis virescens shows that both species produce relatively large amounts of (Z)-11-hexadecenal, with traces of (Z)-9-hexadecenal, (Z)-7-hexadecenal, and hexadecanal. Heliothis virescens females differ from Heliothis zea in that they also produce trace amounts of tetradecanal, (Z)-9-tetradecenal, and (Z)-11-hexadecen-1-ol. In both species, trace compounds are essential to pheromonal activity and specificity of chemical signals.

Isolation, identification and synthesis of the sex pheromone of the citrus mealybug, Planococcus citri (risso)

Abstract The sex attractant pheromone of the citrus mealybug, Planococcus citri (Risso), has been Identified as (1 R - cis )-(+)-2,2-dimethyl-3-(1-methylethenyl)cyclobutanemethanol acetate (VI).

Sex pheromone of the Asian corn borer moth

Abstract By 1975, insect sex pheromones had been identified from 60 species (1) of moths (Lepidoptera), and nearly all of the 40 compounds involved had been found to be mono- or di-unsaturated C10 to C18 straight-chain aldehydes, alcohols, or acetates, and the sites of olefinic unsaturation were, with one exception (2), at odd-numbered positions in the carbon chain. Since that time, many more lepidopteran pheromone components have been identified, and mono-unsaturated compounds with unsaturation at even-numbered positions in the carbon chain remain extremely rare (3–6). However, in females of Ostrinia furnacalis (Guenee), called the Asian corn borer, we have discovered another mono-olefinic lepidopteran sex pheromone that has the site of unsaturation at ab even carbon position. Females of this corn-pest species produce a ca . 1:1 geometric mixture of ( Z )- and ( E )- 12-tetradecen-1-o1 acetate to attract and sexually stimulate males. On the other hand, the nearest taxonomic relative (7) of the Asian corn borer, the European corn borer, Ostrinia nubilalis (Hubner), uses a mixture of ( Z )- and ( E )-11-tetradecen-1-o1 acetate as its sex pheromone (8). Biochemical explanation of the paucity of monounsaturated moth sex pheromones with olefinic sites at even numbered carbon positions remains to be elucidated.

Identification of the pheromone of the Comstock mealybug

Abstract The Comstock mealybug, Pseudococcus comstocki (Kuwana) is a tiny insect that is a serious agricultural pest of citrus, pomegranates, and other fruit in California and elsewhere throughout the world. The fungus that forms on the insect secretions causes severe smutting and results in economic losses to fruit growers. The female insects emit a sex pheromone that attracts males, and traps containing live females have been used to detect infestations. This pheromone has now been isolated from volatiles trapped from an air stream passed over the insects. The identification as 2, 6-dimethyl-1, 5-heptadien-3-ol acetate was made on the basis of chromatographic and spectroscopic data of the natural material and its derivatives. This is the first pheromone identified from the mealybug family and its norterpene (9-carbon) skeleton is uncommon among insect pheromones. The compound was synthesized and shown to be highly attractive in field bioassay at concentrations as low as 0.2 μg per trap.

Sex pheromone of the armyworm,Pseudaletia unipuncta (Haworth) (Lepidoptera: Noctuidae)

Abstract(Z)-11-Hexadecen-1-ol acetate (Z11–16∶Ac) free of theE isomer (<1%), hexadecan-1-ol acetate (16∶ Ac), and a hexadecen-1-ol [the (Z)-11 isomer based on the retention time on a Carbowax capillary column] were identified in extracts of the sex pheromone glands of adult virgin female armyworms,Pseudaletia unipuncta. Also, gas Chromatographic retention times on polar and nonpolar columns indicated the possible presence of (Z)-9-hexadecen-1-ol acetate (Z9–16∶Ac). The ratioZ11–16∶Ac/16∶Ac/Z11–16∶OH/Z9–16∶Ac was 1∶0.15∶0.13∶0.02. Infield testsZ11–16∶ Ac was attractive alone, and the addition ofZ9–16∶Ac,Zll–16 ∶ OH, or 16 ∶ Ac singly or in combination in ratios found in the gland did not increase trap capture.

Isolation, identification, synthesis, and bioassay of the pheromone of the comstock mealybug and some analogs.

The sex pheromone of the Comstock mealybug,Pseudococcus comstocki (Kuwana) was isolated from volatiles trapped from air passing over virgin female insects. Combined gas chromatography, mass and infrared spectroscopy, and microreactions indicated that the structure was 2,6-dimethyl-1,5-heptadien-3-ol acetate. This was confirmed by synthesis; several analogs were also prepared. The natural and synthetic pheromone caused similar trap capture of male insects. Synthetic analogs were significantly less attractive in field tests and the addition of minor amounts of the corresponding alcohol to the pheromone appeared to enhance trap capture, but the results were not statistically conclusive.

Comparative distribution and persistence of disparlure in woodland air after aerial application of three controlled-release formulations

Disparlure, the gypsy moth sex pheromone, was aerially applied to three plots, using a different controlled-release formulation-gelatin microcapsules, flakes of plastic laminates, or hollow fibers-in each plot. Disparlure concentrations in air were measured intermittently over a 34-day period after application. Measurements were made at four heights above ground: 0.3,2,5, and 10m. Wind speed and air temperature were measured concurrently. Disparlure was emitted from the microcapsules and fibers at very high levels for the first day or two; thereafter, all three formulations produced gradually decreasing aerial concentrations. After 32–34 days, concentrations in all plots ranged from 1.5% to 15.5% of those on the first day, although most of the pheromone remained in the formulations. Results suggest that the effective life of all three formulations for mating disruption by atmospheric permeation would be near 30 days under the test conditions, with fibers likely to have the shortest life. Concentrations varied diurnally throughout the experiment, with highest levels generally between 1400 and 2200 hr each day. Concentrations were highest at the 10-m height with microcapsules and at the 0.3- and 10-m heights with flakes, but were similar at all heights with fibers. Biological implications of the results are presented.

Air permeation tests with orfralure for reduction in trap catch of oriental fruit moths.

Orfralure [93% (Z), 7% (E)-8-dodecen-1-ol acetate], the synthetic pheromone of the oriental fruit moth,Grapholitha molesta (Busck), was released into the air of orchard test plots either by hanging plastic laminated dispensers on trees or by aerial dispersal of microcapsules containing a solution of the lure. Trap catch was reduced 95% or more with the most effective formulations, but consistently higher reductions were produced by the dispensers. In tests as long as 28 weeks with dispensers, a single retreatment at midseason maintained an effective concentration.