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ophiou, Ophioii marninnii. Linn, and tUe ceeropia eriptus, Cniptiis cj-trcmatis, 

 Cress., are parasitic njion the American silk worm. Platiisamia cecrojyia, Linn. 

 The large green worm infesting the vines of potatoes and tomatoes is often 

 observed nearly covered with white egg-like cocoons, about the size of grains 

 of rice. The worm is the larviie of the five-spotted sphinx. ^^itJiiii.r celiis. 

 Haw., and the cocoons are those of another hymenopterous parasite. Aimitfeles 

 conpregatiis. Say. The (iccurrenee of these on the worm is brought about iu 

 this way : The adult parasite deposits her eggs in the body of the worm, just 

 under the skin. As soon as the eggs hatch, the small, white, footless grubs 

 which develop from them begin at once to feed upon the fatty parts of the 

 worm, and continue to do so until full growth, when they eat their way out 

 through the skin and sjiin their cocoons, within which they pass the pupal 

 stage, and from which they emerge as adults. These parasites do not. how- 

 ever, always attach their cocoons to the body of the host, and those of this 

 and other species may frequently be observed iu clusters on twigs, grass or 

 weeds, some of them being white, like those just mentioned, others yellowish, 

 and still others are brown ; but they all belong to some of the many species 

 of these useful insects, and should never be wantonly destroyed. These 

 parasites are frequently themselves attacked by a second, and we have even 

 reared a third species. 



Although very diminutive in size, among the entire family of Braconid.f, 

 there are none more useful than those which attack plant lice or " green fly." 

 The female parasite deposits a single egg in the body of the plant louse, often 

 while the latter is quite young. On the hatching of this egg. the young larva 

 at once commences to feed upon the body of its host, internally, while the 

 plant louse increases iu size, gradually assuming an unuaturall.v large and 

 swollen appearance, and eventually changing to a brown colour. Within the 

 body, however, the parasite has been developing, and when it has transformed 

 to the adult it- eats a round hole in the now dry skin of the long since dead 

 host and makes its escape. These large, round. l)rown plant lice are often 

 observed on the leaves of corn and calibage or other vegetables, as well as on 

 the leaves of trees, and illustrate to what extent these useful little insects are 

 engaged in destroying the most insidious pest of the horticulturist and also 

 of the farmer. Aphidins arena phis. Fitch, destroys m.vriads of the grain 

 aphis, and besides this species we have reared eight others from the same 

 insect laost. We have found in all twenty-one species of insects destroying 

 this grain aphis during the la.st few years. 



Syrphus flies are, as a rule, very gail.v coloured, and may not unfrcciuently 

 be mistaken by the unentomologieal for bees. Their maggots are particularly 

 fond of plant lice, Apliidcs, and there are very few species of these prolitic 

 little pests which do not suffer severely from the attacks of these maggots. 

 The eggs are deiiosited among the swarms of plant lice, and the young maggots, 

 as soon as they hatch, begin to feed upon them. As tlie latter grow in age and 

 dimensions they move about among the former and seize one and another of 

 them, sucking out the juices from their bodies, leaving only the empty skin. 

 These maggots are footless and eyeless, of wrinkled, flattened form, very 

 pointed at the anterior and blunt at the posterior extremities. The colour is at 



