Frontalin utilization

Fig. 4 Proposed biosynthetic pathways for the production of ipsdienol in I. pini and frontalin in D. spp. Both pathways utilize an isoprenoid biosynthetic pathway to produce geranyl diphosphate...

The aggregation pheromone of Dendroctonus brevlcomls Leconte consists of a synergistic mixture of exo-brevicomin (IV) produced by females, myrcene (V) from the host tree, and frontalin (VI) produced by males which respond to compounds IV and V. The mixture of all three compounds then attracts males and females (10). Subsequently, verbenone (VII) and trans-verbenol (VIII) are produced and deter further attack (11.). Additionally verbenone deters the response of I. paraconfusus which utilizes the same host tree species in the same area (16,17). Thus the two species may be found colonizing different parts of the same tree. Again, as in the Ips pheromones, chirality plays a role. The naturally occurring enantiomers of exo-brevicomin and frontalin in combination with myrcene elicit a greater response from both male and female D. brevlcomls than do the other enantiomers. 

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