Rolf G. Beutel & Richard A.B. Leschen 
Coleoptera, Beetles. Morphology and Systematics [PDF ebook] 

This book is a revised edition of the first of three volumes in the Handbook of Zoology series which treats the systematics and biology of Coleoptera. With over 380, 000 described species, Coleoptera are by far the most species-rich order of insects and the largest group of animals of comparable geological age. Moreover, numerous species are tremendously important economically. The beetle volumes meet the demand of modern biologists seeking to answer questions about Coleoptera phylogeny, evolution, and ecology. This first Coleoptera volume covers the suborders Archostemata, Myxophaga and Adephaga, and the basal series of Polyphaga, with information on world distribution, biology, morphology of all life stages, phylogeny and comments on taxonomy.