Lepidopterans have a threefold significance for biological science as a whole. First, they show certain features and phenomena that are either unique to this group or virtually so. Such aspects invite investigation simply through their novelty and intrinsic interest. Second, particular lepidopteran groups have features that make them excellent model systems for investigating certain widely shared biological properties or phenomena. Third, the Lepidoptera provide an excellent set of “out groups” for various comparative studies, particularly in evolutionary, molecular, and developmental matters but also for physiological phenomena. In this final chapter we revisit the material presented in the preceding chapters, in terms of the special advantages of lepidopteran research and indicate some possible future lines of investigation that are likely to be of interest.

Unique or special features

As noted, the Lepidoptera exhibit certain features in a more diverse or exaggerated form than is seen in any other animal group. One of these, and a classic area of lepidopteran research, is butterfly wing patterns; their beauty and diversity are apparent to all. Recent years have seen these patterns receiving renewed attention, in terms of general theories of pattern formation. Unfortunately, there is still relatively little molecular biology in this area, and we have not attempted to cover it in this book. For the interested reader, however, Nijhout's recent Development and Evolution of Butterfly Wing Patterns (1991) provides an excellent discussion and review of this subject.