The genus Agriotes is moderately large, containing over 200 described species from all of the inhabited continents except Australia. More than half of the species are Palearctic in distribution, a third occur in the New World (mostly north of Panama), and several species are known from Africa. Twenty-four valid species have been described from North America, three species have been introduced from Europe, and eight species are described here as new; this makes a total of 35 species of Agriotes now known to occur in the United States and Canada.
ln Europe the larvae of several species are of prime economic importance, especially those of sputator, lineatus, and obscurus, which became very troublesome during the World Wars when pasture land was plowed for crops and gardens. These three species now occur in the Maritime Provinces of Canada and in localized areas in southern British Columbia, where they do considerable damage to potatoes and grasses. The wheat wireworm, mancus, is the only native Nearctic species that is of general economic importance, causing damage to wheat, corn, and potatoes.
This study brings together all of the knowledge (except the economic literature on mancus) of the Nearctic species of Agriotes. The must important and enlightening discovery made during the study was the characters of the internal organs of reproduction of the female, especially the sclerotized plates on the bursa copulatrix. These plates and the arrangements of the various glands have been known since the middle of the last century, but, to my knowledge, no one has used these structures taxonomically or as an aid in studying the phylogeny of Agriotes. Through this study of the internal organs of reproduction. I have been able to deduce possible phyletic lines which are less clearly detectable from other characters. For example, the unique form of these organs in the sputator group provides the best evidence for grouping these species together. The salient features of each species, particularly the male genitalia and the bursa copulatrix, are illustrated.
The life-history of only one native Nearctic species, mancus, is known, and this is by no means complete. However, before any life-history studies can be made, the larvae of the species must he associated with the adults. At present, the larvae of only seven of the 32 native species of Agriotes have been definitely associated with the adults.