916 



AN INTRODUCTION TO ENTOMOLOGY 



A classification of this superfamily was published by Ashmead 

 Coo). 



Six of the families constituting the superfamily Ichneumonoidea 

 are represented in America north of Mexico. These families can be 

 distinguished by the characters given in the table above, p. 609. 



Family BRACONID^ 



The Braconids 

 The family Braconidac includes a large number of species, which 



are small or of mod- 

 erate size. In this 

 and in the following 

 family the costal 

 cell of the fore wings 

 has been eliminated 

 by the coalescence 

 of veins (Fig. 1148) 

 and the venter is 

 membranous and 

 has in dried speci- 

 mens a longitudinal 

 fold. In the Bra- 

 conidce the vein be- 

 tween cell Ml and 



Pig. 1 148. — Wings of a braconid. 



coons of a braconid. 



Caterpillar with co- 



cell I St M2 of the fore wing is wanting- 



It is not an uncommon thing, 

 especially in vineyards to find a 

 feeble caterpillar with its back cov- 

 ered with little, white, oblong 

 bodies, which the ignorant usually 

 think are eggs (Fig. 1149). These 

 are the cocoons of braconid para- 

 sites. Th e larva3 obtain their growth 



within the body of the caterpillar, and just before it perishes they 

 leave it, and spin their silken cocoons upon its back. 

 When these cocoons are examined with a lens they 

 are found to be beautiful objects, resembling in 

 miniature those of the sill<:worm. The adult para- 

 site in emerging from its cocoon cuts a neat little 

 lid at its upper end. These parasites belong to the 

 genus Microgaster. Bunches of white or yellow co- 

 coons of Microgaster are often found attached to 

 grass or other plants instead of to the back of the 

 caterpillar which the larvas have destroyed (Fig. 

 1150). 



Perhaps the most interesting of the common 

 forms belonging to this family are those belonging 

 to the genus Aphtdius. The members of this genus 

 are minute creatures which infest plant-lice. If 

 colonies of aphids be examined, the dried bodies of 

 dead ones may be found in which the abdomen is 



