550 HYMENOPTERA 



were formerly considered to belong to the Proctotrypidae or to 

 the Cynipidae (gall-makers), but there can be no doubt, not- 

 withstanding they differ so much in their habits from the para- 

 sitic Chalcididae, that they probably belong to the same family. 

 If treated as different from Chalcididae, they should be separated 

 as a distinct family rather than united with the Cynipidae. 1 



It is impossible for us to do more than allude to the extra- 

 ordinary shapes exhibited by some 



I /lltl\ /tfC~^\ Chalcididae. The genus Thoracantha 



is specially remarkable in this respect. 

 T. latreillei is said to resemble a beetle 

 of the family Mordellidae, and has the 

 wings concealed by false wing-cases 

 really projections from the thorax so 

 FIG. 359. Thoracantha latreillei. that from above the Insect bears no 



Bahia. A, Upper, B, lateral , , T . 



aspect. (After Waterhouse. ) resemblance to the other Insects 01 the 

 Order it really belongs to. 



Howard has called attention to some peculiarities in the 

 pupation of Chalcididae. 2 Like the Cynipidae, they do not make 

 a silken cocoon, but some of them that change to pupae inside 

 the victims on which they were nourished have the power of 

 forming oval cells in which to undergo their transformation, 

 and they thus cause a peculiar inflation of the skin of their de- 

 ceased victim, which after death still continues to serve as a 

 protection to the destroyers. The statement made by Haliday, 

 and repeated subsequently in various works, to the effect that 

 Coryna spins a cocoon under the Aphis in which it has lived, is 

 an error, the cocoon being really formed by Praon, a Braconid 

 that is a parasite of the Aphis, and on which the Chalcid Pachy- 

 crepis (Cory net) lives as a hyperparasite. The pupae of some 

 species differ from those of other Hymenoptera, in that the 

 integument is hard, and the limbs are soldered to the body as in 

 Lepidoptera. These forms pupate external to the victim. 



Fritz Miiller has recorded that the pupa of an unnamed species 

 of Chalcid that attacks a Brazilian ant (Azteca instabilis Forel) 

 is suspended on the wall of the cell the ant lives in by its 

 posterior extremity, just like the chrysalis of a butterfly. 



1 For a systematic memoir refer to Mayr, Verh. zool.-bot. Gcs. Wien, xxxv. 1885, 

 p. 147, etc. 



2 Insect Life, iv. 1891, p. 193. 



