FIELD BOOK OF INSECTS. 



7. Pronotum about one-half wider than long, the sides 

 rather broadly curved, angles prominent; dull brownish- 

 or reddish-yellow; length usually not over .25 in. Adults 



on various garden plants; larvae on roots of grape 



Colaspis brunnea. 



Sides of pronotum straight. Nodonota (third joint of 

 antennae distinctly longer than the second, the last five 

 joints not abruptly wider) and Chrysodina. 



Chrysomelini 



These oval, convex beetles are usually of moderate size 

 and variegated in color. The antennas are of moderate 

 length (see p. 363), the outer joints somewhat enlarged; the 

 eyes are not prominent and their outline is feebly indented ; 

 the pronotum has well-defined side-margins; the elytra 

 cover the abdomen. 



Phyllodecta is distinguished by the tarsal claws being 

 toothed or bifid, and the tibiae neither dilated nor toothed. 



The genera mentioned in this paragraph have the third 

 tarsal joint indented or bilobed. Species of Prasocuris 

 are usually not over .25 in. long; upper surface brassy- 

 green, or bronzed-black, with yellow stripes; pronotum 

 without a thin margin at the base. Plagiodera (punctures 

 of elytra in regular rows; tibia? not grooved on the outer 

 side) and Gastroidea (punctures confused; tibiae grooved) 

 have the sides of the pronotum thickened and unicolorous 

 elytra. G. cyanea is uniform, brilliant, green or blue, and 

 feeds on dock (Rumex) ; polygoni is like it but the pronotum, 

 legs, base of antennae, and tip of abdomen are reddish, 

 and it feeds on knot-grass; both are about .2 in. long. The 

 pronotum of Lina is thickened at the sides and the elytra 

 are usually spotted; length, .25 to .4 in. The pronotum 

 is dark metallic green, with yellow sides, in scripta and 

 inter rupta. The elytra are usually reddish in life, fading 

 to yellow, with rounded black spots, which are some- 

 times merged into transverse bands (interrupta) or are 

 longitudinally elongate (scripta). Both feed on willow, 

 and Populus, and both, sometimes, have the elytra wholly 

 dark-colored. L. tremula is an introduced European 

 species with a green pronotum and unspotted, dull yellow 



368 



