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Show 96 INSECTA. sects, and even Spiders, Aphides, &c., destined to receive their ova, and when hatcbed, to sustain their offspring. In this search they ex· hibit a wonderful degree of instinct, which reveals to. them .the most secret retreats of its objects. Those which are prov1ded wlth a long ovipositor deposit the germs of their race in the fiss~res .or holes of trees, or under their bark. In this operation the ovlposlt.or proper is introduced almost perpendicularly, and is completely chsengaged from its semi-scabbards which remain parallel to each other, and supported in the air, i~ the line of the body. Those females in which the ovipositor is very short, and but slightly or no~ at all apparent, deposit their ova in the body of larvre, caterpillars; and nymphs, which are exposed or very accessible. The larvre of the Ichneumonides, like all the others of the suc-ceeding families ' are destitute of feet. Those which, in the m.a nner of intestinal worms, inhabit the bodies of larvre or caterptllars, where they sometimes forlll 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, how· ever, they perforate their skin in order to open a passage, or put them to death, and there tranquilly undergo their ultimate metamorphosis. 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 agglomet·ated, 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 speci~ s are suspended to a leaf or twig, by means of a long thread. Reaumur has observed that when detached from the bodies to which . they are fixed, they make repeated jumps to about the height of four inches, the larva enclosed in the cocoon approximating the two extremities of its body, and then suddenly returning to a straight line in the manner of various skipping larvre of Dipterous Insects, found on old cheese. This family is extremely rich in species. The difference in the number of joints, found in the pal pi, may serve as a basis of three principal divisions. The first will comprise those species in which the maxillary pal pi have five joints, and the labials four. The second cubital cell is very small, and almost circular or null. We will form a first subdivision with those in which the head is never prolonged anteriorly in the form of a snout or rostrum, in which the ligula is not deeply emarginated, and in which the mal· HYMENOPTERA. 97 illary palpi a re much elongated th · 1 . . t . d'tr . ' eir ast Jomts . ~ por JOn, tuering evident! f· ' 10 . · Y 1 om the precedin •orm and pro-sltor JS not covered at b b g ones. The ovipo-vomer. ase y a large lamina in the form of a Here, this ~vipositor is extt·emely salient. Some species are distinguished from th globul.a r head, their mandi'bles t ermm. ated ine others· by their almost emargmated point and by th I . an entire or but slightly second cubital ceii is frequenetle ongat~on of their metathorax. The form the y wantmg. Such are those which STEPHANus, Jur.-Pimpla, Bracon, Fab. . Where .t he thor ax l·S much thm. ned anterior! lts posteriOr extt·emity with th . . . y, and on a Ie,rel at part of the body appears almoste orl~ml of the abdomen, so that this d . sessi e and inse t d · an superiOr extremity of tlte th . r e m the posterior tl·O r t h'l ghs are inflated d orax as m the E vam.r e. The paste on the vertex(l). ' an several Httl e tu b ercles are observable• XoRIDEs, Lat.-Pimpla, Oryptus, Fab. Where the metathorax is conv that the abdomen is inserted as u ex and .ro~nde~ at its descent, so presents a very distinct pedi~le(2)~ual, at Us mferiOr extremity, and Of those species in which the he . bles are very distinctly bifid or well ad ts t~ansverse, and the mandi-such as form the emargmated at the point , some, PrMPLA, Fab., wiHll acvitee tah ec ylindrical and very briefly pediculated abdomen. We I P ·· persuasoria,· 11c h n eumon perst.tasorius L p nsect. Germ., xix, 18. One f th ' .; anz., Faun. black; spots on the thorax an: th • e largest species in Europe· e scutellum white'· two w hH' e' nat(o1r) Lat. ' Gen er. c rust. et Insect., IX, 3· Br (2), ~:~:' ~:~:;,~r:!~e;tu;described s~ecie:c;;:~e;::ic:.ab.;-Pimpla coro-m~ oe liorato'· ' F ab ., are pro·b ablyn sXeoctr.i,d eIsX· , h4'. 0T he p·zm p la medz.a tor, necator and " rm a separate b ' Is ryptw at V su genus, allied to the preced' ruap or should apparently OL. IV.-N mg one. |
