ICHNEUMON FLIES, 109 



and not followed by a minute rudimentary joint; abdomen with 

 the second and third segments soldered together, the three first 

 segments larger than the others ; ovipositor exserted or concealed ; 

 habits parasitic. 



The Braconidce and Ichneumonidce form together two closely 

 allied families of great extent, of which about 10,000 species are 

 supposed to be described at present ; but although the European 

 species have been discussed by many authors, very little has been 

 published on the exotic species in a connected form. They have 

 been divided into a great number of sub-families and genera, which 

 cannot here be discussed in detail. Many of the foreign species 

 of Braconidce are rather large and handsome insects, often varied 

 with black and yellow, as in Bracon Bicolor, BruU^, which occurs in 

 South Africa. On the other hand, our native species of Aphidius, 

 Nees, and the allied genera, many of which infest Aphidce and 

 other small insects, are themselves small. The best known of the 

 Braconidce is perhaps Microgaster Glomeratus, Linn., a small blackish 

 species, with reddish-yellow legs, which destroys the larva of the 

 common cabbage butterfly (Pieris Brassicce, Linn.), round the dead 

 body of which its little yellow cocoons may often be observed. 

 But for these and other insect parasites, the insects which attack 

 our field and garden crops would prove infinitely more destructive 

 than at present. 



Family V. — Ichneumonidce. 



Antennae not elbowed beyond the scape, always with more 

 than sixteen joints ; scape large, always followed by two small 

 joints ; abdomen sessile or petiolated, often with a long exserted 

 ovipositor ; habits parasitic. 



The Ichneumonidce are rather large and slender insects, and are 

 divided into several distinct-looking sub-families. 



In the typical Ichneumonince the abdomen is depressed and 

 petiolated, the first segment curved, and generally widened near the 

 tip, and the ovipositor is concealed, or but little prominent. The 

 genus Ichneumon, Linn., is itself a veiy large one ; and the great 

 majority of the species are black, either with red legs, or with the 

 antennse, legs, shoulders, scutellum, and legs varied with yellow, or 

 a great part of the abdomen may be either red or yellow in one or 

 both sexes. The species of Tragus, Panz., are rather large insects, 

 measuring an inch or more in length ; they are black, with reddisli 



