14 



The Form of Insects 



In Dragonflies corresponding parts are to be found, 

 but the palp is composed of a single segment only. 

 In Caddis-flies, the palp and hood are well developed, 

 but the blade is wanting. In Moths and Butterflies 

 each hood is long, flexible and grooved ; it can be 

 coupled with its fellow to form the tube through 

 which those insects suck honey or other liquid food. 

 This tube can be stretched out or rolled up in a spiral 



beneath the 

 insect's head. 

 The palps 

 are rarely 

 d e veloped, 

 the blade al- 

 most always 

 absent (fig. 

 13). In Bees, 

 on the other 

 hand, the 

 blade is long 

 and broad, 

 forming a flex- 

 ible piercer 



Fig. II.— Part of Head with jaws of Sawfly {Packyne- (^fiff. I C t7ix\ 



maitis). A. Front of head ; a. labrum ; Ik clypeus ; \ • '' 



c. epicranium, with (d.d.) antennal cavities. CD. there IS nO 



Mandibles. E. ist maxilla; a. cardo ; i. stipes; c. U^^A or>rl tUi^ 



galea; ^. lacinia ; e. palp. B. Fused 2nd maxilla; "OOU, ana tnc 



a. mentum; d. ligula ; c. palp. Magnified. From naln ( flCT 1C 



Marlatt, Bull. 3 (tech. sen), Div. Ent. U.S. Dept. Agr. ^ \ ^ »' •> 



mxp) IS much 

 reduced. In Bugs, Cicads (fig. 14 iii a, b, c) PlantHce, 

 and many Flies the maxillae, like the mandibles, are 

 needle-like piercers, the piercing organ probably 

 representing the blade of the maxilla. The palp is 

 absent in bugs and their allies, but is sometimes 

 present in flies (l, 2). 



Maxillae (Second Pair).— The third pair of jaws 

 in the Cockroach are made up of similar parts to those 



