^6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. lit 



generic name Liidms being truly Elatcr. Liidius, on the other hand, 

 should be applied to the insects generally known as Corymbites, and 

 Corymhites as a generic name disappears." North American writers, 

 in general, follow Hyslop and use Liidms instead of Corymhites, but 

 European coleopterists still cling to the latter or to one or another 

 of the subgenera recognized by Schenkling (1927). In the present 

 study the name Ludhis Eschscholtz includes all species of the fol- 

 lowing generic and subgeneric names: Acfenicerits Kiesenwetter, 

 Anostinis Thomson, Aphotistus Kirby, Calambns Thomson, Corym- 

 hites Latreille. Ctenicera Latreille, Ctenicerus Stephens, Diacanthus 

 Latreille, Haplotarsus Stephens, Hypoganus Kiesenwetter, Liotrichus 

 Kiesenwetter, Prosternon Latreille, Selatosomus Stephens, and Tac- 

 tocomus Kiesenwetter. 



Where possible, the names proposed by Brown (1935, 1936) for 

 various "species groups" of Ludiiis have been used. 



Knowledge of the larvae of the genus Lndius is based upon 44 

 species, 29 occurring in North America and 16 in Eurasia, one being 

 common to both regions. All these, except 6 Eurasian species, have 

 been examined in the present study. 



The genus is extremely diverse, both in habit and in structure. 

 Larvae occur normally in soil, decaying wood, and forest litter, but 

 specimens have been found also in cow dung, mushrooms, and sphag- 

 num, and under stones. Some species prefer dry situations, others re- 

 quire abundant moisture. In the world as a whole, Ludius is the most 

 destructive genus in the Elateridae. But even the most phytophagous 

 species seem capable of sustaining themselves for periods of months 

 or years on decomposing organic matter, or of reverting to predaceous 

 habits when opportunity or necessity arises. Some species are chiefly 

 entomophagous and have never been associated with damage to culti- 

 vated plants. Larvae have been known to attack spiders, the active 

 and inactive stages of various insects, and even members of their 

 own species. 



With the exception of a few pest species, the life history is either 

 unknown or very incompletely known. On the basis of the informa- 

 tion available, the common normal life cycle is as follows : The 

 adults mate and lay their eggs in May and June ; the eggs hatch within 

 a few weeks ; the larvae live for 3 or more years, pupating, when 

 mature, in July or August; the adults develop within a month after 

 pupation and remain in their pupal chambers until the following 

 spring. Pupation occurs in June with some species, and undoubtedly 

 other exceptions will be found as our knowledge of the biology of 



