THE ANIMAL FOOD OP BIRDS. 55 



and remaining quiet for some time. Many of them resemble 

 particles of rubbish of such various sorts as commonly occur 

 at the soil surface. This means of escaping observation 

 doubtless saves some of them from the attacks of birds, but 

 nevertheless a considerable number are eaten by our feath- 

 ered allies. The salient features in the life-history of the 

 family may be gathered from that of the plum-curculio. The 

 adult beetles deposit eggs in the young plums and the result- 

 ing grubs feed upon the pulp of the fruit. They become full 

 grown in a few weeks, the plums fall to the ground, and the 

 grubs enter it to pupate, emerging later as beetles. 



The ants, bees, wasps, sawflies, and various four-winged 

 parasites form the order Hymenoptera. The jaws of these 

 insects are fitted for biting and the remaining mouth parts 

 for sucking. The transformations are complete, and the 

 adults, with few exceptions, have two pairs of membranous 

 wings with few veins. This order includes some highly bene- 

 ficial as well as some extremely injurious species. 



Few families of insects enter more largely into the food of 

 birds than that of the ants (Formicidce). Being abundant 

 in all sorts of situations, it is not strange that woodpeckers, 

 cat-birds, and various other species of birds have learned to 

 rely upon them for much of their food. Some people class 

 ants among the beneficial insects, but, while they are doubt- 

 less useful in certain ways, it seems to us that there can be 

 no question that birds which eat them should receive credit 

 rather than blame for so doing. The ants are so abundant 

 and multiply so rapidly that were there no check upon their 

 increase they would be likely to become very troublesome, as 

 indeed they now are in many localities. 



Probably the most important group of parasitic insects is 

 that comprising the ichneumon-flies of the families Braconidce 

 and Ichneumonidce of modern entomologists. These little 

 creatures vary greatly in life-habits, but a large proportion 

 of them are primary parasites of injurious insects. The 



