376 



ORDER HEMIPTERA. 



(Cicadas, Froghoppers, Bugs, Scale Insects, 

 Aphides, etc.) 



The name ' * hemiptera " is given from the fact 

 that some families have the fore wings divided into 

 two zones — (a) an upper horny, opaque part, (b) a 

 lower membranous and semi-transparent portion. 

 (Plate 52, Fig. 10.) The sub-order Heteroptera 

 (varied wings) includes insects with such wings. 



A more distinct and common feature lies in the 

 mouth parts (Plate 48, Figs. 6 and 7), which are in 

 the form of a jointed sheath enclosing four stylets 

 or hair-like bristles. It is a piercing and sucking 

 mouth. The sheath is in the form of an elongate 

 gutter with much-incurved edges, and the bristles 

 lie along the groove. When about to obtain food, 

 the bristles are pushed beyond the tip of the sheath 

 into the plant tissues, and, being placed closely 

 together, act as a tube to draw up the plant-juices 

 on which most of the insects feed. It is doubtful 

 whether the sheath does any piercing work. It is 

 this type of mouth which makes the pests in this 

 order so hard to combat, as it is useless to 

 apply poison sprays to the plants — one must directly 

 destroy the insect itself. By running a pin along the 

 groove in the sheath one can lift out the bristles. 

 In the cicada and many bugs, only three bristles 

 can be seen ; this may be due to the fusion of two 



