Reviewer 2's Review

“This paper is a combination of research and review material, which makes it rather cumbersome to follow. Many of the statistical analyzes/tests of hypotheses seem chosen more for advocacy than hypothesis testing. Nevertheless, the main point of the paper that long-range pheromones are for finding mates, and other short range cues are needed for final mating success has long been discussed and accepted by behavioral ecologists. This is not a new idea. The relative importance of long- and short-range interactions has been discussed extensively, for example in Baker's research with Oriental fruit moth pheromones (Ann. Ent. Soc. Amer. 1979: 72: pp.173 - 188; Experientia 1983: 39, pp. 112-114), Phelan's chapters on asymmetric tracking (In 1997 'Evolution of insect mating systems in insects and arachnids". Eds. JC Choe and BJ Crespi, pp. 240-256, Cambridge), and a chapter in Carde and Haynes (2004 "Advances in Insect Chemical Ecology' pp. 283-332, Cambridge). It is obvious that long-range attraction is not always necessary or sufficient for isolation, but rather that both processes are involved. Certainly with the OFM, the long-distance attraction is used to bring mates together, but mating does not take place without a courtship behavior involving response of females to pheromones from male hair pencils.

With ECB there is a tendency for moths to aggregate and allow them to find each other without the use of long-distance attraction, but the long-distance pheromones are certainly involved in the overall mating system in general in the field for this species. Taking data from 'mating-in-a-bag' assays to judge the importance of long-range attraction is questionable. There have been no studies to correlate the ability of various males to fly upwind to a female and then to mate with her.

There is no expectation that the divergence of pheromones evolved for the PURPOSE of isolating races. Once in isolation via drift or selection, one would expect divergence in many other traits, including those involved in mating success. The present study does not discuss the possible role of male hair pencil compounds that could be important in close range mating behavior - as described by Lofstedt. It is difficult to follow the genetic input of males in the mating schemes, but it seems possible that the hybridization and backcross scheme could provide males with different hair pencil compounds and allow sexual selection by the females

In summary: This manuscript represents a large amount of work with hybrids and crosses, and data are generated to show that individuals mating in a bag can exhibit differences in short range interactions. However, the whole tone of the paper is to make a mountain out of a mole hill with respect to their conclusions and paper title. Showing that short range interactions are important does not take away from the fact that long-distance pheromones are important in mate location as part of the mating system. This paper could be condensed to a good paper reporting the data that support differences in matings between different genetic material, but without attempting to generate a new and controversial hypothesis when it does not exist. Close-range sex pheromones could very well be involved in the mating differences found in these studies with backcrossed moths, and,thus, pheromones could be important even in the differences noted in this paper.”

N.B. These are the general comments made by the reviewer when reviewing this paper in light of which the manuscript was revised. Specific points addressed during revision of the paper are not shown.