172 



Cassida bivittata— Say. (The Two-Striped Tortoise-beetle.) 



[Fig. 30.] 



Orbicular; yellowish, with two black 

 stripes on each wing-case ; outer one 

 longest and undulate. Larva dull yellow- 

 ish-white ; does not use the anal fork as 

 an excrement bearer. Length, one-fifth 

 of an inch. 



Cassida eivittata, Say. 2, larva ; 3, 

 pupa ; 4, beetle. 



Cassida (Coptocycla) aurichalcea — Fabr. (The Golden Tortoise- 

 beetle.) 



When living, this is a most beautiful object, looking more like a 

 drop of liquid gold than anything else to which we can compare it, 

 being of a uniform transparent golden color, without spot. It differs 

 from the following in being a little more elongate in proportion to 

 the width. Length, about the same as the preceding. Larva dark 

 brown, with a paler shade on the back ; anal fork bearing excrement. 



Cassida (Coptocycla) guttata — Oliv. (The Mottled Tortoise-beetle.) 



Color varies from uniform glossy black to gold mottled and even 

 golden color. Broadly oval — nearly orbicular. Length one-fifth of an 

 inch. Larva uniform green, with a bluish shade on the back ; anal 

 fork bearing excrement. 



Cassida nigripes — Oliv. (The Black-legged Tortoise-beetle.) 



This species, which is larger than either of those already men- 

 tioned, has the power of assuming a golden hue, but is not so brilliant 

 ■as C. aurichalcea. It is distinguished by its larger size, black legs, and 

 three black. spots on each wing-case. Length nearly one-third of an 

 inch ; width three-fourths its length. Larva pale straw-color, with 

 the spines long and tipped with black. 



This concludes my account of the injurious Coleoptera of Illinois, 

 but there is another family to which I desire to call attention, on ac- 

 count of the important service rendered by its species in destroying 

 small injurious species, especially plant and bark lice ; this is Coccin- 

 dlidas, or the lady-bird family. 



COCCINELLHLE. (Lady-birds.) 



Is distinguished by having all the feet three-jointed, or, at least, 

 apparently so; the body rounded and hemispherical in form; the an- 

 tennae enlarged at the tips, and the last joint of the maxillary palpi 

 broad and hatchet-shaped ; the coloration consisting usually of a red 

 or yellowish ground with black spots, or black ground with red or 

 yellow spots; size small, Illinois species seldom exceeding a third of 

 an inch in length. 



Our principal species may be briefly described as follows : 



