INSECT A. 



Some authors have called them Mouches tiijiilex, on account of the three 



fetse which compose their ovipositor, and 

 Mouches vibrantes, because tlieir antenna? 

 are continually vibrating, These organs are 

 frequently curled (contournees), and have a 

 white or yellowish annular spot in the 

 middle. The body is most frequently 

 narrow and elongated or linear, with the ovipositor sometimes exterior ar.d 

 resembling a tail, and sometimes very short, and concealed in the interior of 

 the abdomen, which then terminates in a point, whilst in those where the 

 ovipositor is salient, it is thicker, and as if clavate and truncated posteriorly. 

 Of the three pieces which compose this instrument the intermediate is the 

 only one that penetrates into the bodies in which these insects deposit their 

 eggs ; its extremity is flattened, and sometimes resembles the nib of a pen. 



The females, anxious to lay, are continually flying or walking about, in 

 order to discover the larva?, nymphs, and eggs of insects, and even spiders, 

 aphides, &c., destined to receive their ova, and when hatched, to sustain their 

 offspring. In this search they exhibit a wonderful degree of instinct, which 

 reveals to them the most secret retreats of these objects. Those which are 

 provided with a long ovipositor deposit the germs of their race in the fis- 

 sures or holes of trees, or under their bark. In this operation the ovipositor 

 proper is introduced almost perpendicularly, and is completely disengaged 

 from its semi-scabbards, which remain parallel to each other, and supported in 

 the air, in the line of the body. Those females in which the ovipositor is very 

 short, and but slightly or not at all apparent, deposit their ova in the body 

 of larvae, caterpillars, and nymphs, which are exposed or very accessible. 



The larva? of the Ichneumonida?, like all the others of the succeeding 

 families, are destitute of feet. Those which, in the manner of intestinal 

 worms, inhabit the bodies of larvae or caterpillars, where they sometimes form 

 communities, only attack the adipose substance corps graisseux or such of 

 the internal parts as are not necessary to their existence. When about to 

 become nymphs, however, they perforate their skin in order to open a passage, 

 or put them to death, and there tranquilly undergo their ultimate metamor- 

 phosis. Such also are the habits of those which feed on nymphs or chrysalides. 

 Nearly all of them spin a silken cocoon, in which they become nymphs. 

 These cocoons are sometimes agglomerated, either naked, or enveloped in a 

 sort of tow or cotton, in an oval mass, frequently found attached to the stems 

 of plants. The symmetrical arrangement of the cocoons of one species forms 

 an alveolar body, resembling the honeycomb of our domestic bee. The silk of 

 these cocoons is sometimes of a uniform yellow or white, and sometimes 

 mixed with black or filaments of two colours. Those of some species are 

 suspended to a leaf or twig, by means of a long thread. 

 There are various subgenera belonging to this tribe. 



In the second tribe, the GALLICOLU*, we find but a single nervure in the 

 inferior wings. The antenna^ are of equal thickness throughout, or gradually 



