156 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. Ill 



LUDIUS CYLINDRIFORMIS (Herbst) (?) 



Figure 29, d, e 



Elater cylindriformis Herbst, Natursyst. Ins. Kafer, vol. 10, p. 93, 1806. 

 Corymbites cylindrijormis (Herbst), Germar, Zeitschr. fiir die Ent., vol. 4, 



p. 64, 1843. 

 Liidius cylindriformis (Herbst), Van Dyke, Proc. California Acad. Sci., 



vol. 20, p. 399, 1932. 



This species is known from the eastern provinces of Canada and 

 from the northeastern United States and at least as far west as In- 

 diana, where Blatchley (1910, p. 765) reports its occurrence as 

 "frequent." 



The larvae have been taken from cornfields and gardens, and 

 Hyslop (1915a, p. 9) reports the adults as being abundant in al- 

 falfa and wheat fields. Hawkins (1936, pp. 55-56) implies that the 

 species is a minor crop pest in Maine, but a predaceous tendency is 

 suggested from the observations of Devereux (1878, p. 143), who 

 found a larva crushing the elytron of a living Harpalus pcnnsyl- 

 vanicus. A hibernating larva was found on December 15 at a depth 

 of I foot in a cornfield.^^ 



No adequate description of the larva has been published, but Haw- 

 kins (1936, p. 59, fig. A) figured the ninth abdominal segment. Dis- 

 tinction from the larva of limoniiformis (Horn) is made primarily 

 through greater size, characters of the ninth abdominal segment (fig. 

 29, e) , and the mandibles. 



The largest larva examined was not fully distended, but measured 

 30 mm. in length and 2.6 mm. in breadth. The mandibles are dis- 

 tinguished as follows : Beginning at the distal end of the antennal 

 fossa, a shallow groove extends one-third to one-half the distance 

 toward the tip of the mandible. The ninth abdominal segment 

 (fig. 29, e) bears only 4 sharp "teeth" on each lateral margin of the 

 dorsum ; distance between pleural area and caudal notch approxi- 

 mates one-fifth to one-sixth total length of segment, exclusive of 

 urogomphi ; lateral and ventral aspects of tergite with fewer setae than 

 limoniiformis, usually less than 20 setae on each side. The larvae 

 examined possessed a few transverse rugae or pits on the abdominal 

 mediotergites, especially within the angle of the impressions. 



Material used in study. — Five larvae were examined, four from 

 Springhill, New Brunswick, and one from Riverton, N. J. The 

 species has not been reared, but the material exainined appears to be 

 similar to the larva described by Hawkins (1936) as L. cylindri- 



^2 This observation was made at Riverton, N. J., by C. A. Thomas, of 

 Kennett Square, Pa., and the larva was identified by the writer. 



