18 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



tissues of the caterpillar, hut are seemingly careful to avoid injur- 

 ing any of its vital organs, for as soon as the caterpillar reaches 

 its full growth it changes to a pupa, apparently unaffected. 

 When the maggots have reached their full size each spins up a 

 small silken cocoon inside the pupa, entirely filling up its now dead 

 shell, and instead of a heautiful moth appearing in the spring, 

 a horde of small flies are seen to emerge from a round hole in the 

 side of the pupa, or cocoon. 



Thus large numhers of such pests as the apple-tree tent-cater- 

 pillar (Clisiocampa ameri- 

 cand), bagworms (Thyridop- 

 teryx ephemeraformis) , cater- 

 pillars of the swallow-tailed 

 butterflies which feed upon 

 parsley, carrots, etc., and a 

 host of others, are consumed 

 by members of this family. 



Those belonging to the 

 genus Ophion are partial to 

 the large American silkworms 

 which produce some of our 

 largest and most beautiful 

 moths, and difficulty is fre- 

 quently experienced in rear- 

 ing a desired number of moths 

 on account of the large per 

 cent of cocoons parasitized. 

 The species of the family 

 Braconidce are very similar to 

 those of the preceding one, and contain some equally beneficial 

 insects, feeding as they do upon such pests as the codling moth, 

 webworms, plum-curculio grubs, plant-lice, etc. Some of the more 

 common forms of this family belong to the genus Microgaster, and 

 their small white cocoons may frequently be seen almost covering 

 one of our large tomato- or tobacco-worms (see page 234) , the pupaj 

 of which are often known as "horn-blowers." Many mistake 



FIG. 12. The long-tailed Ophion (Ophion 

 macrurum). a, adult; b, maggot; 

 enlarged. (After Riley.) 



