
AQUATIC INSECTS OF FRESHWATER 

monary functions. The insect rests on the stalks of plants or slowly 
moves over the bottom and is difficult to observe on account of its form 
and the mud on the body. It is a weak flyer and 
only migrates when the pool is dry and in the 
mating season. Food largely consists of the eggs 
of fishes, frogs, snails and insects, but it will 
prey upon other water inhabitants and on young 
tadpoles and fishes. The most generally dis- 
tributed species are N. apiculata, Fig. 198, R. 
fusca, Fig. 199, and R. guadridentata. 
Grant Warer-Bucs belong to the family 
of Belostomatidz, are all strictly aquatic and are 
most dangerous to spawn and young fishes, as 
they are predatory, live on the bottom and feed 
on aquatic animals. In the Eastern section of 
the United States the common forms of these 
bugs belong to the genera Belostoma, Benucus 

and Zaitha; of which the first named are the FIG. 199. Water-scorpion, 
largest and are of elongated oval outline, very flat Ronee [i Enea 
with almost transparent wings of greyish or brownish color. Benucus is 
— as large and may be distinguished by the absence of the double 
groove on the under side of the fore thighs, 
which is characteristic of the first named. 
But one species of Benucus, B. halder- 
manum, is found in the United States. 
The form in Zaitha is like the foregoing 
but the species are smaller. Belostoma 
are abundant in the tropical and temperate 
zones of America, a tropical species, B. 
grande, reaching a length of four inches 
and B. griseum, Fig. 200, the largest of 
the United States attains a length of three 
inches. Their general color is greyish, 
FIG, 200. Giant Water-bug, pee aee yellowish or greenish- brown but they are 

usually covered with mud and when wet are darker in color than in the 
specimen cabinet. The anterior legs are strongly developed to seize their 
prey and the oarshaped posterior legs for swimming. When fully devel- 
oped they have strong wings capable of long sustained flight, which takes 
place at night, and enables them to seek other ponds and water courses 
when theirs dry out. They are often found in cities, their defective sight 
leading them to mistake large reflecting surfaces, like skylights and green- 
25 4 
