Jack R. Plimmer

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).

Riboflavin Photosensitized Oxidation of 2,4-Dichlorophenol: Assessment of Possible Chlorinated Dioxin Formation

Dimeric products are formed by riboflavin-sensitized photooxidation of 2,4-dichlorophenol. The products of this reaction were examined to determine whether chlorinated dibenzo-p-dioxins could be formed from chlorophenols in water by the action of light of wavelengths greater than 280 nanometers. Dimers are formed by union of phenoxy radicals through carbon-carbon or carbon-oxygen bonds. 4,6-Dichloro-2-(2,4-dichlorophenoxy) phenol was obtained in greater quantity than other dimers. Products were characterized by combined gas chromatography and mass spectrometry. Chlorinated dibenzo-p-dioxins which could result from ring closure of a 2-phenoxyphenol derivative were not detected in the products of photolysis. The failure to detect chlorinated dibenzo-p-dioxins may result from the rapid photolytic breakdown of the lower chlorinated dibenzop-dioxins. Under environmental conditions, dioxins are unlikely products of the lower chlorinated phenols or phenoxyalkanoic acids.

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.

An unusual lepidopteran sex pheromone system in the bagworm moth.

The female sex pheromone of the bagworm moth is (R)-1-methylbutyl decanoate. The antipode is biologically inactive and it neither enhances nor detracts from the potency of the R enantiomer. Unlike other moths for which female pheromones have been identified, the female secretes the pheromone from glands on her thorax and it is disseminated from hair that is shed from her body.

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.

Formulation and Regulation: Constraints on the Development of Semiochemicals for Insect Pest Management

Formulation, toxicology, and registration fundamentally influence the successful use of semiochemicals. In this context, “successful” implies that the farmer and the manufacturer will benefit economically and that the potential hazards to man and the environment will not be greater than those from current pest management techniques.

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.