HYMENOPTERA. 1 7 1 



fection the wonderful instinct of knowing just where to 

 sting their victim to render it helpless. Of course a 

 cicada is foolish enough to announce its whereabouts by 

 its shrill singing, so that the cicada killer has little trouble 

 in locating its prey; but the cicada is as powerful as 

 its enemy,- and a good deal more bulky. The tarantula 

 must be "stalked" more cautiously because it makes no 

 noise. For the cicada, one stab is enough; but for the 

 tarantula, owing perhaps to the almost equal wariness 

 of the two contestants, a battle is necessary to decide 

 which one shall come off victor. In either case, it remains 

 that the two big wasps, without being taught, know just 

 where to insert their sting, and both usually are victorious. 



Others of the digger wasps also burrow into the pith 

 of plants and provision the burrows with freshly-killed 

 insects. ' The kind of insect selected is usually so constant 

 that insect collectors come to know their wasp by the 

 kind of insect found in the burrow. 



As to the reproduction of the Sphecina, we may 

 take a typical example. When the egg-laying time 

 arrives, the female selects the place for her burrow, though 

 in one species the insect provision is secured first and 

 laid to one side while the mother wasp digs the burrow; 

 but usually the burrow is first looked after. Then the 

 prey is secured, and this the wasp usually paralyzes by 

 stinging in one of the thoracic ganglia, each one of the 

 bugs or spiders, or caterpillars used. With some of the 

 species the prey is killed; but in either case it is placed 

 in the' burrow, the egg is laid upon it, and the burrow is 

 closed. The mother wasp then goes away to make new 

 burrows, stock them, and lay more eggs. Others of the 

 class take a little different method, amounting to more 

 care in looking after the young. ' With these wasps the 



