40 HOW TO TEACH BEETLES, BUGS, AND LOCUSTS. 
the tarsal groove very much as a jackknife blade 
shuts into the hollow handle. Ranatras are able 
to skim backwards as well as forwards over the 
surface. 
Packard says that the ranatra may often be seen 
walking over the bottom of some quiet pool, where 
it usually escapes observation on account of its 
protective coloring. When thus employed it is 
searching diligently for prey, as may be seen by the 
attitude of its head and powerful front legs. When 
the ranatra finds “game” to its liking, it is seized, 
and the hooks and sharp teeth on the forelegs help 
to hold it, while the sharp beak penetrates the quiv¬ 
ering victim to extract its juices. 
The water-scorpions are said to thrive well in 
aquaria, where their mode of life may be observed. 
SCALE-INSECTS. 
Many plants, especially orange, lemon, and the 
dwarf palms, so common as a decorative plant in 
our homes, are found to have oval brown scales 
upon their leaves and stems. These scales are 
female insects. If a scale be carefully raised with 
a knife-blade and the under surface be examined, 
there will be found an insect which appears to be in 
the larval state. It has no wings. Its legs are 
short and almost obsolete. There appear to be no 
antennae. These females are sluggish and almost 
destitute of ability to move about. 
The males, however, are very active. They have 
