In the New Zealand ecosystem, the reported intraspecific variations in sex pheromone systems are accounted for by variation in the content of the sex pheromone gland. For example, New Zealand greenheaded leafroller, Planotortrix excessana (Walker), populations collected from Auckland and Christchurch were found to use a mixture of (Z)-8-tetradecenyl acetate and tetradecyl acetate. A population from the mid-North Island was found to use two completely different monounsaturated acetates, (Z)-5-and (Z)-7-tetradecenyl acetate (Z5-14:Ac and Z7-14:Ac) . In a field cage experiment, males of the two populations (Christchurch and mid-North Island) were attracted only to pheromone extracts from females of their own population , which suggests that these two populations are sibling species. Further examination of the populations that use Z5-14:Ac and Z7-14:Ac found two populations use two different ratios of these compounds at 3:97 to 71:29 with a small number of females that overlap in both ratios ). However, males from both populations mated with tethered females from both populations, suggesting a cross attraction exist between the two populations. In contrast, two distinct taxa within G. mutans were found: females from an Auckland population produced Z9-14∶OH, Z9-14∶Ac, Z7-14∶OH and Z7-14∶Ac, while females from a Canterbury population produced these four compounds plus Z9-14∶Ald. Male responses from each population were specific to the pheromone blend produced by females of the same population . In the common forest looper, Pseudocoremia suavis (Lepidoptera: Geometridae), three compounds are produced by females that include two major compounds, (Z6)-cis-9,10-epoxynonadec-6-ene and (Z3,Z6)-cis-9,10-epoxynonadeca-3,6-diene, and one minor compound, (Z3,Z6)-cis-9,10-epoxyhenicosa-3,6-diene . Field testing of these compounds in several locations in the South Island revealed two distinct taxa, where males of the first taxon responded to (6Z)-cis-9,10-epoxynonadec-6-ene, and males in the second taxon were attracted to lures containing (Z3,Z6)-cis-9,10-epoxynonadeca-3,6-diene . Since the authors did not analyze sex pheromone gland content of females from different locations, it is not clear if this intraspecific variation is based on the difference in the pheromone blend produced by females paralleled with a tuned male response, or is just a variation in male response. Therefore the case described in our study might be the first example that demonstrates intraspecific variation in the sex pheromone system within a given species based on a variation in male response to sex pheromone and not on variation in the content of the sex pheromone gland. The geographical isolation of the New Zealand ecosystem from the rest of the world provides a great opportunity to shed light on intraspecific and interspecific variation in sex pheromone between species and its role in the evolution of new species.