HEMIPTERA. 133 



The reader should bear in mind that certain of the bird-lice, Mal- 

 lophagidce, infest cattle, the horse, ass, sheep, dog, and cat. These 

 pests have been discussed in an earlier chapter. The true lice of 

 the genus H&matopinus can be recognized by the figures on the 

 two preceding pages. 



For the destruction of these pests upon cattle, poisonous sub- 

 stances must not be used, as injury would result from the animals' 

 licking themselves. They may be safely treated by washing with a 

 strong infusion of tobacco leaves, or by rubbing with an ointment 

 made of one part sulphur and four parts lard, or by sprinkling with 

 Scotch snuff or powdered wood-ashes. The insecticide should be 

 applied thoroughly, leaving no spots untouched where the lice can 

 gather and remain, and from which they can spread over the body 

 again. The application should be repeated several times at inter- 

 vals of three or four days, in order to destroy the young which may 

 hatch after the first application. It is also necessary, in order to 

 make sure of eradicating the pests, to dress with similar agents, or 

 with strong lye, or kerosene, all places where the cattle have been in 

 the habit of rubbing, and the cracks in the stables where they have 

 stood ; or to whitewash the stables and rubbing-places. 



Sub-Order II. -HOMOPTERA.* 



The Homoptera is that division of the Hemiptera in which the 

 wings are of the same thickness throughout, and, when at rest, usu- 

 ally slope roof-like at the sides of the body. This sub-order is also 

 characterized by the absence of a neck, and the position of the 

 mouth-parts at the hinder part of the lower side of the head. So 

 closely is the head applied to the thorax that usually the front coxae 

 articulate with the cheeks, and in many forms the mouth-parts ap- 

 pear to arise from between the front legs. 



Although the Homoptera is a well-marked group, so well defined 

 that by some it is considered a distinct order, the families of which 

 it is composed show great variations in structure, and modes of de- 

 velopment of the species. Some of the' most interesting biological 

 problems presented by Entomology have arisen in the study of this 

 sub-order. 



TABLE OF FAMILIES OF HOMOPTERA. 



A. Beak apparently arising from the sternum, or absent ; tarsi one- or two- 

 jointed : antennae usually prominent and filiform, sometimes wanting. 



* Homoptera : homos (ono$), same; pteron (Trre/jci;'), a wing. 



