B R A C O N I D JR. 



623 



The OATAMKTOI-KS have the she'd quadrilateral "r 



ovoid, with tin- front transverse ;nnl knotted ; the 

 cpistoma very short, the abdomen of the male not 

 'lecupyinir the space !>et\veen the hind legs. 



The Ox YSTOMDS liavc tho shell orbicular and arelied 

 in front, which is not produced into a point. The 

 cpistoma is obsolete. 



i5U ACOMD/K (Stephens). A family, or rather 

 subfamily, of li ynicnoptcrons insects belonging to the 

 section Pttpojrfiaga, and forming a portion of the Lin- 

 iKeaii genus Ichneumon. They are distinguished from 

 .lie true ichneumons by wanting the internal discoidal 

 cell of the upper wings, by having the maxillary 

 palpi five-jointed, and the labial ones either three or 

 four jointed ; the recurrent nerve is cither unique or 

 entirely wanting. The appearance of these insects 

 bespeaks a certain weakness of structure. They arc 

 of small si/c, their legs are long, the abdomen is 

 attached bv its whole breadth to the thorax, or is 

 sometimes pedunculatcd, the ovipositor is often ex- 

 scrted, (he wings are generally obscurely coloured, 

 with bands or spots, the prevailing colours are luleous 

 red and lilack, the antenme are never ornamented 

 with a pale hand, the maxillary palpi are often very 

 long, and the labial always short. There is consider- 

 able difference in the details of the economy of these 

 insects, all ho\ve\er are parasitic, in their larva state 

 within the bodies of other insects. 



The species of Aphidius prey upon the plant-lice ; 

 one of them having been long known to entomologists 

 under the name of Irhiiriitiion ii)>lndn>n of Linnaeus 

 and l)e (ieer, but as the specific name has been 

 transformed into a generic one, it has become ncccs- 

 !o substitute another term. Ne.'s MUI Ksenbcck 

 has accordingly given it the name of A/>//iiluix rnritt.t 



in his Hymenopterorum Mouographia' (I MM j), whilst 

 Mr. Haliday, from finding it attached to the plant- 

 licc of the rose trees, has termed it .Ijil/ii/n/x rota, a 

 name scarcely correct since it <!oes not feed upon (lie 

 but upon the insects which swarm upon that 

 plant; moreover, Lsenbeck obtained i'. fnun the 

 aphides of the pine and buckthorn. As this is a 

 genus of considerable extent and interest, ( Mr.llaliday 

 having <leseribed upwards of forty British species,) 

 and as it was omitted in its place in the alphabet, we 

 shall here give some account of it. It. is distinguished 



Apliidius P 



by the abdomen being peduneulated, the maxillary 

 palpi live-jointed, the labial with thiee equal joints, 

 and the peduncle smooth. \Ve are indebted to Mr. 

 Haliday for a very interesting account, of the habits 

 of the species above named, and which, although we 

 have ourselves repeatedly observed the proceedings 

 of these injects, we prefer giving in the words of that, 

 elegant. writ'T. "This is the species most, frequently 

 noticed by authors, being a familiar inhabitant of our 

 gardens, where the male may be seen throughout the 

 summer hovering over the rose trees, or creeping 

 under the leaves. His partner is of less roving habits 



and will generally he found busy in providing for tne 

 establishment of her numerous progeny. Placed at 

 her birth amid the myriads of pucerons which encircle 

 the young shoots of the rose, she has no dwelling to 

 construct with art fid industry, nor stores of food to 

 collect by distant rovings. With extended antenna- 

 and wings shivering with desire, she paces leisurely 

 among the defenceless herd, and as soon as she has 

 selected one by a light touch of her antenna , she 

 stops short at about her own length from it, and rising 

 on stiffened legs bends her abdomen under her breast 

 till the end of it projects beyond hi r mouth, then 

 erecting her thorax by depressing the hinder part 

 she simultaneously makes a plunge forward with the 

 abdomen which is then extraordinarily lengthened, 

 and by a momentary touch deposits an egg on the , 

 under side of the pneeron near its tail. The victim 

 will sometimes kick and sprawl so as to discompose 

 her, but, being anchored by its sucker plunged in the 

 bark, can make no effectual attempt to elude the 

 deadly weapon. Should it, however, be wandering 

 at large, and free to struggle, she shows great activity 

 in traversing around it in the attitude of attack till 

 she can take it in (lank. The delicate .'-ense of the 

 antenna' seems to warn her where a germ has been 

 already deposited, as she will pass by those which 

 have been stung some days before ; and I have never 

 found more than a single grub in each individual. 



When all the interior of the pneeron is consumed it, 



will be found separate from its fellows, and motionless 

 usually on the upper side of a leaf, to which it is glued 

 by some viscid exudation. It now appears distended 

 and of an opaque Ira/el or lighter tint. If opened 

 the full fed grub of the aphidius will be discovered 

 doubled up and filling the cavity, its head being next 

 the tail of the puceron. In a short time the parts of 

 the perfect, insect are developed in a quiescent, state, 

 and in the same position, the in! egnmcnls of the giub 

 being shrivelled up below as if in black grains. Like 

 cynips and cullimonie, it, spins no cocoon for its 

 transformation, being adequately protected by the 

 indurated skin of its victim. A few days are suliicient 

 to give consistence to its parts; and while the new 

 risen sun is yet glistening in the early dews, the 

 winged insect by a push of its head detaches tin- 

 latter rings of its case, which -eparate in the form of 

 a circular lid, often springing back to close the orifice 

 after the inhabitant has gone forth, born in the matu- 

 rity of her energies and instincts, to renew the circle 

 of existence." 



The other genera belonging to this family arc, 

 Sfcfi/ii/iiiis, Jnr. ; ('if/iiiiii.'i, N. ab K. ; ,S'/)c/////'i/.v, N. ah 

 1C.; I't-rililitx, N.ab K. ; llybrizon, Fallen; Lr'utphnni, 

 N. ab. K. ; Itracan, Fahricius ; Agtilli'm, Latrcillc ; 

 iMirn>tliis, N. ab K. ; Honii'ms, N.ab K. ; fc/nii'iitf.i, 

 N. a)) K. ; Afifn>x'i.i/rr, Latreillc; H/nrtix, N. ab L. 

 Mr. llaliday has added several others, such as Minu\ 

 as well as various subgencra. 



The genus liracnn, forming tho type of the family, 



is distinguished by its sessile abdomen, five-jointed 



maxillary palpi, three-jointed filiform labial palpi, with 



! the abdomen longer than the thorax, slightly convex 



I or depressed, the segments gradually decreasing in 



I size, tne jaws horny and toothed, and the antenna' 



setaceous. This genus is for the most part composed 



of elegant exotic species having coloured wings. There 



are about twenty British species, chiefly of small si/.e. 



They are generally found amongst plants or upon 



trees, running about the leaves upon which various 



larva' are feeding, whence it may be inferred that 



