Synthesis of citrophilus mealybug sex pheromone using chrysanthemol extracted from Pyrethrum ( Tanacetum cinerariifolium).

A commercial pyrethrum extract was used as a source of chrysanthemol for the synthesis of the citrophilus mealybug ( Pseudococcus calceolariae) sex pheromone. The chrysanthemic acid esters (pyrethrins I) were isolated and subsequently reduced to obtain chrysanthemol, which was used for ester pheromone synthesis. Field tests showed that the pheromone synthesized using plant-derived chrysanthemol was as attractive to male P. calceolariae as the pheromone obtained using a commercial isomeric chrysanthemol mixture.

Synthesis of (6R,12R)-6,12-Dimethylpentadecan-2-one, the Female-Produced Sex Pheromone from Banded Cucumber Beetle Diabrotica balteata, Based on a Chiron Approach.

Herein we describe a synthesis of (6R,12R)-6,12-dimethylpentadecan-2-one (5), the female produced sex pheromone of banded cucumber beetle Diabrotica balteata Le Conte, from (R)-4-methyl-5-valerolactone, a methyl-branched chiron.

Photoremovable protecting groups as controlled-release device for sex pheromone.

Photoremovable protecting groups (PRPGs) were demonstrated as a delivery device for controlled release of pheromone under both UV light (≥350 nm) and direct sunlight irradiation. In the present work, (Z)-11-hexadecen-1-ol (sex pheromone of Chilo infuscatellus Snellen) was chemically caged by four different photoremovable protecting groups (7-hydroxy-4-hydroxymethylcoumarin, 1-pyrenemethanol, 9-anthracenemethanol and 2-(hydroxymethyl)anthraquinone) individually. Photophysical studies showed that the caged pheromone with coumarin, pyrene and anthracene derivatives exhibited strong fluorescence. Controlled release of (Z)-11-hexadecen-1-ol was achieved by irradiating the caged compounds in aqueous ethanol both under UV and sunlight. Further, to mimic the environmental conditions, controlled release of (Z)-11-hexadecen-1-ol was also studied in soil medium under direct sunlight. Thermogravimetric analysis showed that caging of (Z)-11-hexadecen-1-ol by PRPGs significantly reduced its volatility. Bioassay experiments indicated that PRPGs are harmless to soil bacteria (Azotobacter sp. and Pseudomonas aeruginosa) and in vitro cytotoxicity studies on eukaryotic L929 cells showed that PRPGs are also non-toxic. Field bioassays were performed using caged pheromone against maize stalk borer (Chilo partellus) and the results showed that the caged alcohol is effective in a number of moths catches instead of free alcohol in a blend for a longer period of time. Our studies indicated that use of PRPGs as delivery device for controlled release of pheromone by sunlight holds great interest for field applications.

Synthesis and field test of three candidates for soybean pod borer's sex pheromone.

Three candidates for the soybean pod borer's sex pheromone, dodec-10-en-1-yl acetate (E:Z = 95:5) (9a), (E, E)-dodeca-8, 10-dien-1-yl acetate (9b) and (E)-dodec-8-en-1-yl acetate (9c), were synthesized through the coupling reaction between Grignard reagents and acetates catalyzed by Li2CuCl4. Furthermore, the compounds 9a, 9b, and 9c, when tested in the field, showed that dodec-10-en-1-yl acetate (E:Z = 95:5) (9a) has promise as a lure for male soybean pod borer.

Attraction of Chrysoperla carnea complex and Chrysopa spp. lacewings (Neuroptera: Chrysopidae) to aphid sex pheromone components and a synthetic blend of floral compounds in Hungary.

BACKGROUND: The deployment of synthetic attractants for the manipulation of lacewing populations as aphid predators is currently used in integrated pest management. This study investigates a synthetic bait comprising floral compounds previously found to attract the Chrysoperla carnea complex, and, for the first time, the aphid sex pheromone components (1R,4aS,7S,7aR)-nepetalactol and (4aS,7S,7aR)-nepetalactone, in field experiments in Hungary, for their ability to manipulate lacewing populations. RESULTS: The synthetic floral bait attracted both sexes of the Chrysoperla carnea complex, and Chrysopa formosa Brauer showed minimal attraction. The aphid sex pheromone compounds alone attracted males of C. formosa and C. pallens (Rambur). When the two baits were combined, Chrysopa catches were similar to those with aphid sex pheromone baits alone, but carnea complex catches decreased significantly (by 85-88%). CONCLUSION: As the floral bait alone attracted both sexes of the carnea complex, it showed potential to manipulate the location of larval density via altering the site of oviposition. Aphid sex pheromone compounds alone attracted predatory males of Chrysopa spp. and can potentially be used to enhance biological control of aphids. For the carnea complex, however, a combination of both baits is not advantageous because of the decrease in adults attracted. Assumptions of intraguild avoidance underlying this phenomenon are discussed.

Improved synthesis of (3E,7Z)-3,7-tetradecadienyl acetate, the major sex pheromone constituent of the potato pest Symmetrischema tangolias (Gyen).

An efficient six-step synthesis of (3E,7Z)-3,7-tetradecadienyl acetate, the major component of the sex pheromone of the potato pest Symmetrischema tangolias (Gyen), is described, starting from the commercially available dihydropyran. The stereoselective formation of the 7Z double bond is accomplished by a Wittig reaction, while the 3E double bond is formed by a modified Knoevenagel condensation. The overall yield of the synthesis is 28%, giving the final product in high stereochemical purity (95%). The simplicity and the low cost of the herein reported synthesis suggest the potential practical use of the above pheromone in integrated management programs, for this serious insect pest.