A BEETLE 5 
INSECTA 
A COLEOPTEROUS INSECT. A LARGE BEETLE 
Compare the animal with the wasp. We notice, in the first 
place, the heavier and clumsier body and the smaller head. 
The animal is evidently much less active and also less intel- 
Jligent than the wasp. We notice, also, that the wings lie close 
to the body instead of being raised above it. The forward or 
mesothoracic wings are hard and thick; they are not used for 
flight, but cover the metathoracic pair and the hinder part of 
the body and are called the wing-covers or elytra. They form, 
thus, an additional protection to the back. The entire body of 
most beetles, in fact, has a thicker cuticula and, consequently, 
a more effective external covering than that of the wasp. 
This feature may be correlated with the smaller intelligence of 
the animal. Opening the elytra, we notice beneath them the 
membranous metathoracic wings with which the animal flies; 
we notice also that they are folded transversely as well as longi- 
tudinally. These wings are wanting in some of the running 
beetles, where the wing-covers are sometimes fused. Note the 
scutellum, the small triangular plate, between the base of the 
wing-covers. Find the eyes and note their small size. Are 
ocelli present? Find the antenne; in some beetles they are 
often concealed beneath the sides of the head. 
Exercise 1. Draw an outline of the dorsal aspect of the 
beetle on a scale of 4 or 5, First, however, spread 
and pin the right wing-cover and wing. Number the 
thoracic and abdominal segments and label all the parts 
observed. 
