PARASITICA 



539 



Fam. III. Chalcididae. 



Pronotum ivith some freedom of movement, its angles not extend- 

 ing to the insertion of the front wings. Antennae elbowed, 

 consisting of from seven to thirteen joints. Wings without 

 a system of cells ; with a single definite nervure proceeding 

 from the base near the front margin, or costa ; afterwards 

 joassing to the costa, and giving off a very short vein more or 

 less thickened at its termination. The sjJecies are, with few 

 exceptions, of parasitic habits. 



The Insects of this family the Pteromalini of Eatzeburg 

 are frequently of brilliant colours and of remarkable form ; the 

 species are very numerous, some 4000 or more having already 

 been described. Of this number nearly 3000 are European, 

 and as there is good reason for supposing that Chalcididae are 

 quite as numerous in the Tropics and in the New World as they 

 are in Europe, the family will probably prove to be one of the 

 largest in the class. About twenty sub-families have already been 

 proposed for the classification of the group ; they are based 

 chiefly on the number of joints in the tarsi, and the details of 

 the antennae and of the ovi- 

 positor. This latter exhibits 

 great variety in external ap- 

 pearance, due chiefly to the 

 modification in form of the 

 basal, or of the following ven- 

 tral abdominal plates, one or 

 more of which may be pro- 

 longed and altered in form or 

 direction, giving rise in this 

 way to considerable diversity 

 in the shape of the abdomen. 

 Correlative with this is a 

 great variety in the mode 

 of parasitism of the larva. 

 Many live in galls, feeding on 

 the larvae of the makers of the galls or on those of the inquilines : 

 others attack caterpillars, others pupae only ; some flourish at 

 the expense of bees or other Hymenoptera, or of Coccidae 



Fig. 355. Eurytoma ahrotani, male. 

 Britain. Hyper-parasite through Micro- 

 gaster of Liparis dispar, and according 

 to Cameron, parasite of Rhodites rosne 

 and other gall-flies in Britain. x 10. 

 (After Ratzeburg.) 



