SAWFLIES, ANTS, WASPS, BEES, ETC. 103 



\\ iilgs, is a groove into which the hooks tit. Tlie 

 effect of this combination is to present a larger 

 surface or ''sail" to enable the insect to fly with 

 greater power, for most hymenopterous insects have 

 good flight. The mouth is modified from the typical 

 biting-mouth of the cockroach, etc., in accordance 

 with the habit of these insects of feeding upon the 

 nectar of flowers. Yet it is not a purely sucking- 

 mouth as seen in butterflies and moths. There 

 are always mandibles present (see Plate 14, Figs. 

 I and 2); these are used for various purposes; 

 bees use them to cut and knead the wax for the 

 cells of the hive ; paper-nest wasps use them to tear 

 pieces of wood with which to make the "paper" 

 for their nests, and also to seize and tear their 

 prey; while mud-daubers use them to work 

 up the pellets of mud into "bricks'/ for their little 

 earth-cells or rooms, and also to cut and tear th'j 

 soil if they burrow in the earth. Some ants use the 

 mandibles very effectively as weapons of defence 

 and attack, they can piece their foe with the stout 

 prominent mandibles (see Plate 14, Fig. i,), and then 

 spray the wound with poison or formic acid. 



We will take the bee's mouth as a type for the 

 Order Hymenoptera (see Plate 25, Fig. 4), though 

 the mouths of the other insects in this group ma} 

 vary more or less from this type. 



If a bee is soaked in a weak solution of potash 

 for a couple of days, and the front part of the head 

 cut off, and examined first with a lens and then 

 with the microscope, the following parts can be 

 separated and noted. (See Plate 25, Fig. 4.) The 



