THE GIANT WATER-BUGS. 1043 



nesota and Iowa, and south to Florida, Texas and the West 

 Indies. The eggs are large and spherical and are attached to 

 the stems of rushes and other water plants. Uhler (1884, 256) 

 calls it : 



"The facile master of the ponds and rivers of the Atlantic States. 

 Developing in the quiet pools, secreting itself beneath stones or rubbish, 

 it watches the approach of a mud-minnow, frog or other small-sized 

 tenant of the water, when it darts with sudden rapidity upon its un- 

 prepared victim, grasps the creature with its strong clasping fore legs, 

 plunges its deadly beak deep into the flesh and proceeds with the utmost 

 coolness to leisurely suck its blood. A copious supply of saliva is poured 

 into the wound and no doubt aids in producing the paralysis which, in 

 small creatures, so speedily follows its puncture." 



II. Lethocerus Mayr, 1852, 15. 



The larger species of this genus resemble very closely those 

 of Benacus, but are readily distinguished by the shorter legs 

 with much broader fore femora which are deeply grooved in 

 front for the reception of the tibiae and tarsi ; middle and hind 

 femora also grooved. About ten species are known, five from 

 North America, three of these occurring in our territory. They 

 were formerly classed under the generic name Belostoma, now 

 applied to the smaller species formerly known as Zaitha. Bueno 

 (1923, 397) says that the eggs of Lethocerus are laid in masses 

 under stones, planks or logs in wet places near their haunts. 



KEY TO EASTERN SPECIES OF LETHOCERUS. 



a. Sides of elytra obviously, but feebly, curved; middle and hind legs 

 vaguely if at all annulate. 

 b. Width of interocular area subequal to that of one eye; legs com- 

 paratively long and stout; length, 50 or more mm. 



1182. AMERICANUS. 



bb. Width of interocular area greater than that of one eye; legs shorter 

 and more slender; length, 40 to 45 mm. 1183. OBSCURUS. 



aa. Sides of elytra straight and subparallel from base to apical third; 

 middle and hind legs distinctly annulate; length, 40 — 48 mm. 



1184. UHLERI. 



1182 (1388). Lethocerus americanus (Leidy), 1847, 58, 66. 



Elongate-oval. Color above a nearly uniform dull brownish-yellow, 

 more or less mottled or streaked with wavy fuscous lines ; scutellum 

 sometimes with three vague paler spots; under surface in great part dull 

 yellow dotted with fuscous, the sides and hind margins of sterna often 

 darker; femora dull yellow vaguely mottled with black; tibiae and tarsi 

 fuscous-brown. Vertex narrower and less convex than in B. griseus. 

 Front femora very broad, the groove bordered each side by dense dark 

 brown velvety pile. Length, 50 — 55 mm.; width, 19 — 21 mm. (Fig. 210). 



