From the preface:
"After several expeditions to the south of India, one of us (T. M.) reckoned that it was time to start working on a complete revised checklist of sphingids frequently encountered in the state of Karnataka, India. We decided to publish a field guide that would be easy to use for students, amateur entomologists and even scientists confronted with this marvellous family of moths.
We went on to produce a well-illustrated book. Both sexes of all species are depicted in colour figures supplemented by comparative plates to ease determination in difficult cases. The best characters for the easiest determination in the field or when facing a spread specimen are pointed out. The identification of species is usually straightforward, but some genera are intricate. Such intricate genera are, for example, Ambulyx Westwood, 1847 and Macroglossum Scopoli, 1777, but we do not think that there is any great risk of confusion within the geographic area under consideration.
For all species, we provide quality pictures of the male genitalia. In some cases, these are indispensable for reaching a reliable determination. Whenever possible, known food plants of each moth species are specified. This information is mostly excerpted from Bell & Scott (1937). We strongly recommend the reading of this fabulous work to all interested in grasping the distribution and ecology of hawkmoths in India.
In some cases, we have had to take systematic decisions, for example concerning certain members of the genera Ambulyx, Polyptychus [Hübner, 1819] and Marumba Moore, , even though this was not our primary intention when working on this book. Please keep in mind that this work is neither a revision nor a taxonomic study. It is meant to be used by people that just wish to put a name to and to find more about sphingids they happen to come across."