Dendroctonus spp

Barkawi L. S., Francke W., Blomquist G. J. and Seybold S. J. (2003) Frontalin de novo biosynthesis of an aggregation pheromone component by Dendroctonus spp. bark beetles (Coleoptera Scolytidae). Insect Biochem. Mol. Biol. 33, 773-788. 

In some insects, fatty acid elongation followed by decarboxylation produces the hydrocarbon pheromones, and these include examples of lepidopterans (Jurenka), dipterans [71], the German cockroach [72a] (see Fig. 6) and the social insects [73]. More recent work in bark beetles has shown that Ips and Dendroctonus spp. produce their monoterpenoid-derived pheromones ipsenol, ipsdienol and frontalin by modifications of... 

Ips spp. bark beetles use a variety of terpene alcohols for communication. Among these are cw-verbenol (234, Scheme 46), ipsenol (240a, Scheme 50), and ipsdienol (266 a, Scheme 52). c -Verbenol was first synthesized by Silverstein et al. (51, 136) by stereospecific reduction of verbenone (233) with sodium borohydride. Mori (47) synthesized Irani-verbenol (232), a Dendroctonus spp. attractant, by lead tetraacetate oxidation of a-pinene (230) followed by hydrolysis of the resultant acetate (Scheme 46). Repeated recrystallization of the 3 3-acetoxyetienic acid ester afforded optically pure lra 5-verbenol. Oxidation (48) of the optically pure irawi-epimer to verbenone and reduction with lithium aluminium hydride yielded optically pure cM-verbenol. 

A number of different stresses can elicit inducible compounds important in insect interactions with plants. Some of these compounds appear to attract insects to a plant in distress, such as the southern pine beetle, Dendroctonus frontalis, to Pinus spp. Other compounds appear to prevent attack [22]. Ozone decreases soybean resistance to insect herbivory and overrides induced resistance [Lin, H.C. Kogan, M. Endress, A.G., Environ. Ento. 1990, in press.]. This might be due to a diversion of phenolics into coumestrol instead of more toxic compounds such as glyceollin. 

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