814 



FAMILY XL.— LAMPYRID^E. 



IV. Plateros Bourg. 1879. (Gr., " broad + Eros.") 



In this genus the sides of thorax are strongly reflexed ; the disk 

 without the transverse ridge seen in Eros, and consequently with- 

 out cells. The elytra have nine narrow and usually equal slightly 

 elevated lines, separated by rows of line quadrate cells. Sometimes 

 the alternate lines are a little stronger, so that the elytra become 

 feebly 4-costate. The species are very difficult to separate. Eight 

 are known from the United States, five of which have been taken in 

 Indiana. 



KEY TO INDIANA SPECIES OF PLATEROS. 



a. Antennae broad, not strongly serrate. 



6. Elytra with alternate lines distinctly more elevated, the intermediate 

 ones very feeble. 1545. modestus. 



bb. Elytra with all the lines equal or nearly so. 



c. Thorax with a small notch at middle of base, the discal black spot 

 with a pale margin on all sides. 1546. sollicitus. 



cc. Thorax not notched at base, the discal spot reaching the base and 

 usually the apex. 



d. Median impressed line of thorax distinct, reaching from base to 

 middle. 1547. canaliculatus. 



dd. Median impressed line of thorax obsolete, represented only by 

 a small roundish impression in front of scutellum ; antennae 

 shorter ; form more narrow. 1548. floralis. 



aa. Antennae strongly serrate; thorax with a median impressed line on 

 basal third. 1549. lictor. 



1545 (4794). Plateros modestus Say, Bost. Journ. Nat. Hist., I, 1835, 153; 



ibid. II, 631. 



Elongate-oblong, subdepressed. Black, sides and apical margin of tho- 

 rax reddish-yellow. Third joint of antennae one-half the length of fourth, 

 the second much smaller. Thorax with sides strongly elevated, apex 

 rounded, hind angles somewhat prolonged. Elytra as mentioned in key, 

 the more elevated lines with two rows of cells in intervals, these rows 

 separated by the finer lines. Length 6-7.5 mm. 



Crawford Connty; rare. June 8. A broader species than those 

 which follow. 



1546 (4796). Plateros sollicitus Lee, Journ. Phil. Acad. Nat. ScL, 2d 



Ed., I, 1847, 83. 



Elongate, subdepressed, narrower than canaliculatus. Dull black ; tho- 

 rax reddish-yellow, with a large square, central, shining black spot. Tho- 

 rax with sides strongly reflexed, the median impressed line extending from 

 base to beyond middle, deepest on middle third. Elytra with well marked 

 equal intervals and strongly cross-barred interspaces. Antennae of male 

 long, the fourth joint twice as long as third, fifth twice as long as wide, 

 outer ones narrower, with angles acute. Antennae of female shorter, sev- 

 enth joint twice as long as wide. Length 6-7.5 mm. 



Starke County ; scarce. Jnly 27. The thorax is narrower, with 



