A. W. Ry.aikk Roberts 110 



Definition of the word "Wireworm," 



Many farmers and gardeners, even yet, use the word "Wireworm" 

 in a loose way to include millipedes and centipedes as well as the larvae 

 of Elateridae. The two former must obviously be excluded, and the only 

 question that arises in regard to the name is as to how many of the 

 latter should be included. 



In many papers on applied entomology, both in America and in this 

 country, the term has been used to denote the larva of any Elaterid 

 which is known to be destructive to crops. Curtis (7) himself uses it in 

 this way; in one place (p. 153) speaking of eleven species of wireworms, 

 though eventually (p. 189) he refers to the "true wireworms" as Agriotes 

 lineatus, A. obscurus, A. sputator and Athous haemorrhoidalis. West- 

 wood (25) in his Classification (p. 237) refers to Agriotes lineatus and 

 A. obscurus as "ther wireworm," being in some doubt whether the latter 

 is specifically distinct from the former. He says they (i.e. the wireworms) 

 are so called from "their cylindric form and hard texture." This defini- 

 tion was meant of course to apply to the two species named only, but 

 it is equally applicable to the other species of the genus. It does not 

 apply to an equal extent to species of other Elaterid genera which may 

 be classed as "pests." Following Westwood therefore, the name should 

 belong exclusively to the genus Agriotes. 



Since, however, the word has been so generally used in recent years 

 to denote the larva of any injurious Elaterid, it seems undesirable to 

 define it any more closely than did Curtis, but to use it as applying 

 primarily to the larva of the genus Agriotes and to that of Athous 

 haemorrhoidalis, F. The larvae of other species of Elaterids may eventu- 

 ally also have to be included, such as those of Athous hirtus, Hbst. 

 {niger of Brit. Cat.) and Corymbites cupreus, F. 



The principal distinguishing characters of Agriotes larvae are as 

 follow : 



(i) The presence of a tooth, situated dorsally, on the inner edge of 

 the mandible, near its apex, and 



(ii) the two eye-like pits situated near the base of the 9th abdominal 

 segment. These pits, originally supposed to be spiracles, are now usually 

 referred to as " muscular impressions," e.g. by Ford (ii) and Henriksen (15), 

 but are believed to be sensory organs and are here referred to as " sensory 

 pits." 



Athous haemorrhoidalis, F. may be distinguished readily from all the 

 species of Agriotes in the larval stage by the absence of the characters 



