196 Bugs, Cicadas, Aphids, and Scale-insects 
We come now to the “true bugs,” representing twenty-six families and 
constituting the Heteroptera, the largest of the three suborders of the 
Hemiptera. The classification of the members of this large group into 
families, by the use of the keys commonly used by entomologists, demands 
the recognition of such small and obscure structural characters that I have 
tried to find some easier means for the use of the amateur and general col¬ 
lector. As collecting and observing in the field imply the discovery of 
insects in their native haunts, we may acceptably make use of constant 
habits for a basis of convenient grouping. About one-third of the Heterop- 
terous families are aquatic in habitat, and of these the members of some 
are to be found on the surface of pools and ponds, of others swimming 
Fig. 268.—Wings of Heteroptera, showing disposition of veins in membrane character¬ 
istic of various families: 1, Capsidse; 2, Pyrrhocoridae; 3, Lygasidae; 4, Coreidae: 
5, Nabidae; 6, Acanthiidae. (After Comstock.) 
or crawling about below the surface, and of two, only partly aquatic, 
on the shore, but always by the water’s edge. Some of these aquatic bugs 
are to be discovered occasionally in flight far from water, as the giant 
water-bugs and others, when circling about electric lights or in search of 
new homes. But the structural signs of the aquatic habitat, legs flattened 
and fringed so as to be fitted for swimming, will betray these estrays. 
Occasionally, too, a strictly terrestrial bug will be found on the surface of 
a pool, but his violent and obviously unaccustomed and awkward attempts 
to swim to shore will betray him. So we may begin an acquaintance with 
the Heteroptera by resorting to the nearest pond or quiet stream-pool. 
On the surface are the familiar water-striders, or skaters. Their long, 
spider-like legs, narrow and black or oval and yellow and black body, 
and swift nervous running distinguish them from all other bugs. They 
are members of the family Hydrobatidae, and the commoner species belong 
to the genus Hygrotrechus (Figs. 269 and 270). Upheld by the tense surface- 
film of the water, their feet only make little dimpled depressions in the sur¬ 
face, the shadows of which may often be seen on the sandy bottom. The 
locomotion is really due to a sort of surface rowing or gliding, and not a 
