B. A. Bierl-Leonhardt’s research while affiliated with Agricultural Research Service and other places

(E,E)- and (E,Z)-8,10-Dodecadien-1-ol acetates were identified in a 1∶4.3 ratio in the extract of abdominal tips of female filbert-worm moths,Melissopus latiferreanus (Walsingham). The identifications were based on electroantennogram (EAG) analysis, gas chromatography, mass spectrometry, ozonolysis, and synthesis. TheE,Z isomer produced the stronger EAG response. In the field tests of various ratios ofE,E∶E,Z, the ratio found in the extract captured the most males. The pureE,E isomer initially was not attractive by itself (<0.1%E,Z) but became attractive after a few days, presumably because of isomerization. TheE, Z isomer (<0.1%E,E) was attractive initially, but this compound might have isomerized faster than theE,E isomer. A study of the isomerization showed that regardless of the initial mixture of 8,10-dodecadien-1-ol acetate isomers, almost complete equilibration existed after one month. The equilibrium mixture consisted of 9%Z8,E10, 65%E8,E10, 23%E8,Z10, and 3%Z8,Z10. Concentrations in rubber septa (1∶4 ratio ofE,E toE,Z) of 0.03-3.0 mg/septum produced equivalent trap catches.

Field tests were conducted in sparsely infested areas of Massachusetts to evaluate the effectiveness of microdispersable formulations of racemic disparlure in disrupting mating of Lymantria dispar (L.). The incidence of mating of laboratory-reared female moths placed in treated plots was significantly less than that in control plots, and the degree of mating disruption was correlated with the amount of disparlure applied. The number of male moths captured in (+)-disparlure-baited traps was also correlated with the incidence of mating. In plots treated with 50 g/ha, only 2% mating was observed, compared with 65% mating in control plots.

Heptane washes of the excised ovipositors of Choristoneura parallela (Robinson) (Lepidoptera: Tortricidae) females were analyzed by capillary chromatography with polar and apolar liquid phases, by capillary gas-chromatography-mass spectrometry. and by microchemical degradation techniques. A mixture of four compounds was found that serves as a sex pheromone blend; (E)-11-tetradecen-1-ol is the major component and (Z)-11-tetradecen-1-ol, tetracadecan-1-ol, and (E)-11-tetradecen-1-ol acetate arc minor components. Field traps baited with a mixture of these four compounds captured as many C. parallela males as traps baited with virgin females. Population-monitoring studies using the pheromone in Maryland showed that C. parallela is bivoltine.

(Z)-11-Hexadecen-1-ol (Z11-16:OH) was isolated from extract of the sex pheromone gland of female Xylomyges curialis Grote (Lepidoptera: Noctuidae) and identified by gas chromatographic and by gas chromatography-mass spectrometric analysis of the parent compound, the acetate derivative, and the ozonolysis product of the acetate derivative. No other unsaturated alcohols, acetates, or aldehydes could be detected in the extract. In field tests, traps baited with synthetic Z11-16:OH effectively captured males.

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.

(Z)-11-Hexadecenal was identified from heptane washes of ovipositors of female artichoke plume moths, Platyptilia carduidactyla (Riley), by using glass open-tubular capillary chromatography, combined capillary chromatography-mass spectrometry, and microchemical degradation. The washes were free of detectable quantities of any other pheromone-like compounds (C12 to C18 olefinic acetates, alcohols, or aldehydes). In the field, insect traps baited with 100 μg of (Z)-11-hexadecenal captured artichoke plume moth males at a greater rate than traps baited with virgin female moths. The chemical and field results together indicate that the long-range female sex pheromone of this species is a single component.

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.

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

Air permeation trials were conducted to determine whether trap catches of the peachtree borer (PTB)Synanthedon exitiosa (Say) and lesser peachtree borer (LPTB)S. pictipes (Grote and Robinson) could be reduced through application of the synthetic pheromone of the PTB, (Z,Z)-3,13-octadecadien-1-ol acetate (Z,Z-ODDA), at 92% isomeric purity. The pheromone was released into the air of peach orchard test plots with hanging laminated plastic dispensers or hollow fiber dispensers in the trees and by aerial dispersal of microcapsules containing a solution of the lure. Results showed that all formulations ofZ, Z-ODDA reduced trap catches of both PTB and LPTB in treated plots relative to catches in traps in untreated plots. In one air permeation experiment, three types of laminated dispensers and one type of hollow fiber dispenser each reduced trap catch of PTB by 93–100% and of LPTB by 75–95%. In a separate test, two formulations of microencapsulatedZ,Z-ODDA did not reduce trap catch of male PTB as effectively as the laminated dispenser; results for LPTB were similar for both the dispensers and microcapsules. Catches of male PTB moths in traps baited with laminated and or fiber pheromone dispensers containing ODDA (946%Z,ZE,Z) were not significantly different. LPTB male moths were also captured in these traps, the catches being dependent upon the initial pheromone loading and the type of dispensers.