Robert M. Silverstein

Brevicomin: Principal Sex Attractant in the Frass of the Female Western Pine Beetle

The principal component of the sex attractant produced by the female western pine beetle (Dendrotonus brevicomis) is exo-7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane; the trivial name brevicomin is suggested.

Sex Attractants in Frass Produced by Male Ips confusus in Ponderosa Pine

The attractant response of Ips confusus to frass produced by male beetles boring in ponderosa pine can be reproduced, in a laboratory bioassay, by a combination of compound I with either compound II or compound III, all isolated from frass. The same response by both sexes was elicited by mixtures of synthesized compounds. Compound I is (—)-2-methyl-6- methylene7-octen-4-ol; compound II, (+)-cis- verbenol; and compound III, (+)-2-methyl-6-methylene-2,7-octadien-4-ol.

Western pine beetle: field response to its sex pheromone and a synergistic host terpene, myrcene.

In the field, both sexes of the western pine beetle, Dendroctonus brevicomis, are attracted by the female-produced bicyclic ketal exo-brevicomin; this response is enhanced by myrcene (a constituent of the beetles host, ponderosapine), which is not an attractant by itself. This synergism may be part of the phenomenon of the mass attack on its host. Temnochila virescens chlorodia, one of the principal insectan predators of this beetle, is attracted by exo-brevicomin alone.

Identification of two new terpene alcohols from frass produced by Ips confusus in ponderosa pine

Abstract Two new terpene alcohols have been isolated from frass produced by Ips confusus feeding in ponderosa pine. They are (−)-2-methyl-6-methylene-7-octen-4-ol and trans-2-methyl-6-methylene-3,7-octadien-2-ol as determined by spectral analyses; they serve as internal markers in the isolation of the sex pheromone.

SEX ATTRACTANT OF THE BLACK CARPET BEETLE

The principal component of the sex attractant of the black carpet beetle Attagenus megatoma (Fabricius) is trans-3, cis-5-tetradecadienoic acid.

Synthesis of the principal components of the sex attractant from male Ips confusus frass: 2-methyl-6-methylene-7-octen-4-ol, 2-methyl-6-methylene-2,7-octadien-4-ol, and (+)-cis-verbenol

Abstract We have synthesized the three terpene alcohols previously identified as the principal components of the sex attractant produced by the bark beetle, Ips confusus. The compounds are: 2-methyl-6-methylene-7-octen-4-ol (I), 2-methyl-6-methylene-2,7-octadien-4-ol (II), and (+)-cis-verbenol (XIII).

Sex Attractant of Female Dermestid Beetle Trogoderma inclusum Le Conte.

Two components of the sex attractant of a female dermestid beetle Trogoderma inclusum Le Conte were identified. They are (-)-14-methyl-cis-8-hexadecen-1-ol and (-)-methyl-14-methyl-cis-8-hexadecenoate. Other Trogoderma species also respond to the compounds.

Synthesis of brevicomin, principal sex attractant in the frass of the female western pine beetle

Abstract The sex attractant, brevicomin [ exo -7-ethyl-5-methyl-6,8-dioxabicyclo[3.2.1]octane ( 1 )] from the frass of the western pine beetle, Dendroctonus brevicomis , was synthesized through acid catalyzed hydrolysis and cyclization of the cis -epoxide ( 8 ). The endo -isomer ( 2 ), also present in frass but inactive, was formed on cyclization of the trans -epoxide ( 9 ).

A flavone feeding stimulant in alligatorweed

Abstract A compound partially responsible for the feeding of Agasicles beetles on alligatorweed has been isolated and identified as 7-α- l -rhamnosyl-6-methoxyluteolin (I).

Isolation, tentative identification, and synthesis studies of the volatile components of the hairpencil secretion of the monarch butterfly

Abstract The major volatile components of the hairpencil secretion of the male monarch butterfly have been identified as benzyl caproate and either 1, 5, 5, 9-tetramethyl-10-oxabicyclo[4.4.0]-3- decen-2-one(1), or 2, 2, 6, 8-tetramethyl-7-oxabicyclo[4.4.0]-4-decen-3-one(2). One sequence designed to synthesize 1 yielded two isomeric products of structure 1 whose spectra are very similar to each other but distinctly different from those of the natural product; this sequence also yielded a tricyclic ketal (9). A second sequence gave two epimeric spiro compounds (12) and a third sequence gave a [4.3.0] ring system (14).