Gagne's introductory chapters include biographical sketches of those individuals who have contributed most to our knowledge of Neotropical gall midges. He also discusses classification and distribution, external anatomy and biology, and techniques for collecting, rearing, and preparing specimens for study. The heart of the book comprises two chapters. The first presents the midges themselves: identification keys to the genera, a synopsis of each genus and higher taxon, and a list of all known species from South America. The second includes keys and descriptions of galls and other damage caused by the midges, with known hosts.

The book brings to light the most recent findings on the biogeography, biodiversity, host plant induction and natural history of gall inducing insects in the Neotropical region. We attempt to summarize the work done so far in the region, promote several syntheses on many aspects such as host induction, host specialization, distribution among the several vegetation types and zones, the origin of super hosts and the mechanisms leading to geographical patterns in their distribution. Furthermore, the book constructs new perspectives for deeper understanding of galling insect evolutionary ecology and biogeopgraphy in the region.

This book provides practical ecological, ethological, evolutionary, and biogeographic data for gall-inducing cecidomyiids, their galls and host plants, based on field surveys, laboratory experiments and genetic analysis. It refers to various researches on gall-inducing insects published by a world of biologists. Practical methods of field surveys and data analysis are presented, as well as topics on parasitoids, invasive pests, and beneficial gall midges that would be useful for applied entomologists. Readers can learn an ecological way of thinking through diverse interrelations between insects and plants, and the analysis of ecological data from gall-inducing cecidomyiids. Galls can be easily observed in the field continuously from early to final stage of the development of galls and gall inducers because of their outstanding features and immobility. It provides important data of the host plant such as phenology, abundance as food resources, and the survival of galled organs. By taking these advantages, many biologists have used galls and gall-inducing insects as highly convenient organisms for a wide range of studies including ecology, ethology, evolution, and biogeography. The book primarily intends to present the appeal of galls and gall-inducing insects for various biological studies. In particular, gall-inducing cecidomyiids are ideal insects to study ecology and evolution. It helps to open the doors to further cryptic study subjects. Also, integrating various ecological, ethological, evolutionary and biogeographic data as shown in this book can serve to further advance the macroevolutionary studies of insects.

While volume 1 includes several introductory chapters and treats 42 families of flies in the Lower Diptera, volume 2 covers the remaining 64 families of flies that make up the Higher Diptera (or Cyclorrhapha). These include families of house flies, fruit flies, bot flies, flower flies and many other lesser-known groups. The text is accompanies by over 1660 line drawings and photographs.

This text brings together fundamental information on insect taxa, morphology, ecology, behavior, physiology, and genetics. Close relatives of insects, such as spiders and mites, are included.