370 



ZOO LOOT. 



Order 4. Hemiptera. — Insects of tliis group are called 

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

 sucking mouth-parts, the mandi- 

 bles and first maxillaB are bristle- 

 like, and ensheathed by the labium 

 or second maxillte. There are no 

 palpi except in Thrips and the 

 bird-lice. The metamorphoses are 

 incomplete, the larva being like the 

 adult, except that the wings are ab- 

 sent. Many bugs secrete a disa- 

 greeable fluid from glands seated in 

 the metathorax. The lice are low, 

 wingless parasitic Hemiptera. The 

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

 sus leucopterus Uhler) are types of the order. 



Fig. 331. — Cor- 

 eus tristis, aquaali- 

 bug. 



Fig. a35.- 

 Thrips. 



-Seventeen-year Locust. 



pupa ; d, incisions for eggs.— After Riley. 



An aberrant form is Thrips (Pig. 335, Thrips cere'alium), 



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



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



