^8 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, III 



Liidius sexualis is evidently a plains species. In native situations 

 it is associated with prairie grasses, especially with mixed grass and 

 silverberry (Elaeagnus) and to a lesser degree with the grassy mar- 

 gins of snowberry (Symphoricarpos) thickets. It persists for many 

 years after such areas have been brought under cultivation. The 

 species has been found in some abundance in a few old bromegrass 

 fields which originally contained large areas of snowberry. Larvae 

 have been taken at depths ranging from near the soil surface to 22 

 inches. King (1928, p. 705, "Ludiiis (?) sp.") lists sexualis among 

 the wireworms of lesser economic importance in Saskatchewan. 



The larva strongly resembles that of a much larger unidentified 

 species (possibly cruciatus festivus LeConte), from which it may be 

 distinguished by size, the urogomphi (fig. 16, c, d), and the habitat. 



Description of "mature" larva. — Length 16 mm., when fully dis- 

 tended; greatest breadth 1.6 mm. None of the specimens examined 

 were larger. Segments usually subequal in width, sometimes wider 

 in region of mesothorax, metathorax, and first to third abdominal 

 segments. Body moderately robust; with moderately large mem- 

 branes on lateral aspect; all segments broader than long; head and 

 ninth abdominal segment about four-fifths greatest body width. 

 Dorsum pale yellow or light brown (near "cinnamon-buff," Ridgway, 

 1912) ; mouthparts and prongs of urogomphi darker, head and pro- 

 thorax sometimes slightly darker ; venter slightly paler. Dorsum 

 slightly rugose ; scattered minute, shallow pits usually observable on 

 some segments. 



Head subquadrangular with strongly arcuate sides ; somewhat 

 flattened above and below. 



Frontoclypeal region with posterior part extending backward to 

 foramen magnum ; truncate posteriorly. Two prominent anterior 

 nasosulcal setae on each side of base of nasale. Nasale consisting of 

 large median tooth with a fine lateral projection on each side near 

 base; lateral projections usually eroded away, giving nasale uniden- 

 tate appearance. Subnasale indefinite and variable; usually without 

 denticles ; sometimes a few minute, sharp denticles arising from ven- 

 tral surface of nasale almost halfway up median tooth, arranged in 

 irregular transverse row. Paranasal lobes produced beyond nasale, 

 each bearing 3 to 5 setae (i or 2 small). 



Epicranial plates with sparse, fine, inconspicuous punctures. Dorsal 

 sulci shallow, each with 5 setae subequally spaced, the most anterior 

 seta being long, others small. Ventral sulci bearing row of 5 to 7 setae, 

 usually 2 to 5 conspicuous. Lateroepicranial setae include dorsal and 

 ventral pairs (usually i large and i small seta in each pair) with i 



