Ostrinia furnacalis

A second and perhaps more common possibility is suggested by the occasional attraction of male moths to compounds very closely related to actual constituents of a pheromone. For example, in wind tunnel trials, about 5% of the males of the strain of the European com borer (O. nubilalis) that uses (Z)- and ( )-l 1-tetradecenyl acetate in a 97 3 ratio are attracted to a 2 1 mix of (Z)- and ( )-12-tetradecenyl acetates, which is the mix of the Asian com borer, Ostrinia furnacalis (Roelofs et al, 2002). Such occasional mistakes also are found in many species when the attractancy of pheromone analogs are evaluated in the field small proportions of males are attracted to the wrong lures. The presumption is that there is a heritable basis for such deviance in at least some of these males. Again, these compounds could be recognized by forgiving receptors (Vickers et al., 1991 Baker,... 

Zhao, C., Lofstedt, C. and Xuying, W. (1990). Sex pheromone biosynthesis in the Asian corn borer Ostrinia furnacalis (II) Biosynthesis of ( > and (Z)-12-tetradecenyl acetate involves delta-14 desaturation. Archives of Insect Biochemistry and Physiology 15 57-65. 

The antifeedant activities of all clerodanes (of natural and semisynthetic origin) have been reported in an extensive review8 covering all literature until December 2001. This review covers a total of 382 clerodanes, all tested on a variety of insect species, yet most tests are with Spodoptera species, of which S. littoralis is most often used. Other species frequently used are the CPB (L. decemlineata), Helicoverpa armigera, P. brassicae, and Ostrinia furnacalis. 

Toosendanin (39) from the Chinese species Melia toosen-danan displays activity as strong as azadirachtin against larvae of Spodoptera litura and has better activity than azadirachtin against the yellow stemborer, Scirpophaga incertulas, and the Asiatic comborer, Ostrinia furnacalis (Fig. 25.11) (Towers et al., 1989). 

An alternative, plausible scenario for the switch from 11- to A12-tetradecenyl acetates in O. furnacalis that cannot be excluded is a stepwise change. First, 12-tetradecenyl acetates would be added to the An-tetradecenyl acetates, followed by the elimination of the 1 -(etradecenyl acetates. The initial addition of the l2-componenis and the subsequent loss of the An-components could have been favored by either communication interference or reinforcement (sensu Butlin) in contact with other Ostrinia spp. using the ancestral An-components. 

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