INTRODUCTION

Not altogether coincidentally, the three families of Neuroptera discussed in this book are those on which most biological and taxonomic information and understanding is available. They are the most widespread, predominant, and diverse families in the northern temperate regions, where the foundations of early knowledge on the order were laid, and the use of lacewings in pest control was pioneered. All are more widespread, and all have recently been subject to comprehensive global review and reappraisal, so that much of the early scattered information has been brought together, reevaluated and synthesised, keys to generic level produced, and some constructive comment on their diversity, evolution, and biogeography is feasible. However, biological information on most species, and many genera in other parts of the world, is not available or is fragmentary. Although some inferences can be made from the species already studied, the considerable biological variability within each family suggests that extrapolation from the few well-studied species in each should be cautious. Likewise, despite the impetus provided by recent overviews, many new species await discovery and description, and the minefields of over-simplified treatment of complex species groups are exemplified well in the following chapter on Chrysoperla, a single genus of Chrysopidae (Henry et al., this volume).

This chapter is a broad introduction to the systematics and biogeography of the Coniopterygidae, Hemerobiidae, and Chrysopidae, to provide a perspective for the remainder of this book, and to help readers appreciate the complexity of the groups considered – as well as the opportunities they may furnish for study and manipulation in the future.