THE LADY BEETLES. 



511 



stems of the larger ragweed (Ambrosia trifida L.) in the low bottom 

 lands of the Wabash River. 



III. Hippodamia Mills. 1846. (A mythological name.) 



Thorax subtransverse, not margined at base ; claws bifid ; hind 

 tibial spurs distinct, Casey (Joe. tit.) lists 27 species of the genus 

 from the United States, while Leng, in a later paper (loc,. cit.), re- 

 duced these to ten, the others being regarded as either geographical 

 races or synonyms. Of these four and one variety are known from 

 Indiana. 



KEY TO INDIANA SPECIES OF HIPPODAMIA. 



a. Thorax black with broad pale lateral margins within each of which is 

 a black dot ; tibia? and tarsi pale. 974. 13-punctata. 



ua. Thorax with a narrower white lateral margin, without distinct dot, but 

 usually intruded upon by a more or less pronounced angulation of 

 the central black area ; legs black throughout. 

 1). Black disk of thorax nearly divided by a white quadrate spot at the 

 middle of base, and an elongate triangular spot at apex. 



975. PAEENTHESIS. 



bb. Black disk of thorax without white spot at base and apex, but with 

 two discal divergent white dashes. 

 c. Front half of elytra without markings or with only a humeral 

 black dot. 976. glacialis. 



cc. Elytra each with six small spots, three of which are on the front 

 half. 



d, Spots of elytra all small and widely separated. 



977. CONVEJRGENS. 



dd. Spots much larger, the front one near suture apparently double. 



977a. var. 1 5 - m a c u lata . 

 *974 ( 3050). Hippodamia 13-punctata Linn.. Syst. Nat., X. 1765, 336. 



Oblong-oval. Head black at base; thorax described in 

 key and without discal divergent bars ; elytra each with six /dp|^ 

 rounded black spots and a small common scutellar spot. T ^J^^BU 

 Readily known by the pale tibiae and tarsi and the mark- I (MSB) 

 ings of the thorax. Length 4.5-5.2 mm. (Fig. 187.) y 'IIP' > 



Frequent throughout the northern half of State; (A&RuIy.) 

 less so southward. February 23-December 25. In one specimen 

 from Laporte County the black area embraces nearly the entire 

 upper surface of thorax and the spots of elytra are nearly double 

 the usual size. 



*975 (3051). Hippodamia parenthesis Say, Journ. Phil. Acad. Nat. Sci.. 

 IV, 1824, 93 ; ibid. II, 232. 

 Oblong-oval. Head black at base and apex ; thorax described in key ; 

 elytra reddish-yellow, with a large triangular common scutellar spot, a 

 round spot on humerus, and a strongly curved subapical lunnle on each, 

 black. Length 4-5 mm. 



[33—23402] 



