This order once encompassed all insects with a complex network of wing veins, regardless of whether their metamorphosis was incomplete or complete.  By the early 20^th century, most of the species had been transferred to new orders, leaving only a small percentage of the insects once assigned to the Neuroptera remaining in that order.  By the second half of the 20^th century, some of the taxonomists began to believe that the fragmentation of this order had gone too far, and that the order Megaloptera needed to be grouped in some way with Neuroptera, either by making them suborders of the ... Read moresame order or by creating a superorder to accommodate both.

Because only a relatively small number of species are still included in Neuroptera sensu lato, this book provides keys to all known South American species that have been described well enough to be identified with any degree of certainty.  Many species in the family Chloropidae, the neuropteran family with the greatest number of recognized species in South America, have proven to be valuable as biological controls for insect pests in agriculture.  Their importance for tropical agriculture is another reason for including terrestrial species in this book.