68 



according to the food or the circumstances under which they live. Those species which 

 feed on animal food or under bark, have shorter and thicker beaks than those which 

 derive their nourishment from vegetation, and as the former are for the most part 

 beneficial and feed on other insects, this is a very important distinction for everyone to 

 become familiar with. The beak consists of the labium, which is so modified as to form a 

 hollow sheath, by having its two sides turned up, so that a deep groove is left in the 

 middle of its upper surface, which acts both as a canal up which the juices on which the 

 insect feeds flow, and also as a sheath for four delicate sharply pointed setce or bristles 

 which are actually the jaws and maxillae modified for a special use. It is with these 

 instruments that the insect punctures the plant or animal from which it derives its food. 

 The insects comprised in this order are of the most anomalous shapes, and there are 

 embraced within its limits some of the most curious and wonderful forms of insect life. 

 Their geographical range is very wide, for there is hardly any part of the globe of which 

 the land and water do not produce their own peculiar form.s. The number of species 

 classed within this order is said to reach nearly 10,.500, which are about equally divided 

 between the two sub-orders into which the Hemiptera are divided. These two sub-orders 

 are called Hemiptera-heteroptera and Hemiptera-homoptera, which again are divided into 

 divisions and sub-divisions, and the latter of these are distributed into families which 

 contain the various genera and species. 



It was Latreille who divided the Hemiptora into these two divisions : " The Hom- 

 optera are the higher in rank, as the body is more cephalized, the parts of the body more 

 specialized, and in the Aphidse which top the series, we have a greater sexual differentia- 

 tion, the females being both sexual and asexual, the latter by a budding process, and 

 without the interposition of the male, producing immense numbers of young which feed in 

 colonies. The Heteroptera, on the other hand, have the body less compactly put together, 

 the abdomen and thorax are elongated, the head is small compared with the rest of the 

 body, and the species are large (a sign of degradation among insects) and several families 

 are aquatic, indicating a lower grade of development, while representatives of these were 

 the first to appear in geological times. Their afiinities are with the Orthoptera and Neu- 

 roptera, while the Homoptera whose bodies are more cylindrical ally themselves with the 

 first and higher series of sub-orders." — (Packard). 



For convenience sake we will take a short glance at the Heteroptera first, and then 

 pass on to the Homoptera. 



In the Hemiptera-heteroptera (ercpos = various, irrepa = wings) the hemely tra are thick 

 and opaque at the base, but membranous and translucent at the tips ; they lie horizontally 

 on the top of the back and cross each other obliquely so that the translucent part of one 

 overlaps the same part of the other. The underwings which these cover are entirely 

 membranous ; the head is horizontal and bears on its front part the articulated promuscis 

 or beak which is bent down and carried underneath the breast. Between the wings there 

 is a scutellum which is generally triangular, but which is sometimes so large as to cover the 



whole of the upper side of the body, leaving 

 only the margins of the fore-wings visible. 

 (See figure 83). The modes of life among 

 these bugs are very varied ; animals, birds, 

 insects and plants are all liable to their attacks, 

 and they are sometimes exceedingly destruc- 

 tive. For the most part they are found upon 

 the plants on which they subsist ; but others 

 again feed on weaker insects found in similar 

 situations. They continue active and require 

 food during all their stages. The larvae are 

 distinguished by the total want of any appear- 

 ance of wings ; whilst in the pupae the rudi- 

 ments of these limbs appear on the back of the 

 thorax. All of these insects have ocelli or 

 simple eyes on the front of the head between the two large compound eyes, but these, like 

 the wings, are only developed in the perfect state. 



Fig. 83. 



