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03O THE STUD Y OF INSECTS. 



having the ovipositor of the female curved up over the dor- 

 sum of the abdomen to the thorax. Our most common 

 species is Leucospis affinis (L. af-fi'nis) ; this measures about 

 three eighths inch in length. 



Family Proctotrupids (Proc-to-tru'pi-dae). 

 The Proctotrupids {Proc-to-iru 'pids). 



These insects, in spite of their long family name, are the 

 smallest of the parasitic Hymenoptera ; and in fact the 

 smallest of all known insects belongs to this family. The 

 larger species rarely exceed one twenty-fifth of an inch in 

 length ; the smallest, Alaptus excisus (A-lap'tus ex-ci'sus), 

 measures between six and seven one-thousandths of an inch. 



In shape, the body is slender, and the 

 color is almost invariably black or 

 brown without metallic lustre ; the 

 prothorax extends back on each side 

 to the cup-like scale covering the base 

 of the fore wing; the wings are often 

 wanting, and when present are en- 

 tirely veinless, or they may approach 

 the venation of some of the Chalcis-flies, or in other cases 

 that of some of the Braconidae ; the ovipositor issues from 

 the apex of the abdomen. Figure 761 represents a Procto- 

 trupid greatly enlarged. 



The Proctotrupids are nearly all parasitic ; and very 

 many of them infest the eggs of other insects. The female 

 Proctotrupid bores a hole with her ovipositor through the 

 shell of an egg of one of the larger insects, and deposits one 

 of her eggs inside of it. Here the young parasite when it 

 hatches finds itself in the midst of food which is sufficient 

 for it till it is fully grown. The transformations are passed 

 within the infested egg, from which the parasite comes forth 

 an adult. Other species are internal parasites of larvae, 

 and some are secondary parasites, that is, parasites upon 



