370 



ZOOLOGY. 



Order 4. Hemiptera. Insects of this group are 

 bugs. They all (except the bird-lice and Thrips} 

 sucking mouth-parts, the mandi- 

 bles and first maxillae are bristle- 

 *\ /. like, and ensheathed by the labium 

 \JL/ or second maxillae. There are no 

 j^fr v palpi except in Thrips and the 

 X vBBv > bird-lice. The metamorphoses are 

 f I J incomplete, the larva being like the 

 \ ( adult, except that the wings are ab- 



sent. Many bugs secrete a disa- 

 t&iK'iiSS^ greeable fluid from glands seated in 

 bu s- the metathorax. - The lice are low, 



wingless parasitic Hemiptera. The 

 squash-bug (Fig. 334, Coreus tristis) and chinch-bug 

 sus leucopterus Uhler) are types of the order. 



called 

 have 



Fig. 336. Seventeen -year Locust, a, b, pupa ; d, incisions for eggs. After Biley. 



An aberrant form is Thrips (Fig. 335, Thrips cereaUum), 



with long, slender white wings and free biting mouth-parts. 



While most insects live but a year or two, or three at the 



