ENTOMOLOGIST AND BOTANIST. 



297 



original intention of tlie author, and render 

 more complete the "Joint-worm"' article already 

 alluded to. This paper, from its importance, 

 will commend itself to tlie scientific portion of 

 our subscribers ; and the generalizations con- 

 tained in it will amply repay its perusal by tlie 

 more general reader. AVe sliail, as far as we 

 are able, complete it, by adding a description of 

 (? Antigastcr mirahilis. EDrrou. 



On tlic (irouji EiirytdHlides (if the liyiritMioiitproils 

 Kaiiiily Chalcididin : 



WITH KKMARKR ON TIIK TIIKOKY OK SI'KCIKS, AND A 

 PKSCRIPTION OK ANTIGASTKU, A NKW AND VEUV 



ANOMALOUS GENUS OF (HALCIIHO.K. 



IIY UEn.l. I». WALBII, M.A. 



FAMILY CHALCIDID^. 



'incd on tlic pattern sltoivn 



Hi-',y«ml,'i, : 



Froill IFin 

 4, 7 and 9.» 



This very difficult and very ixttusivc f;imily lisvs hitlurlo 

 been almost cntii'i'ly neglected by the entomologists of the 

 UnitedStiit.es. I have materials lor the revision of all the 

 different groups found in this country; hut to complete such 

 a work would require far more space than is here available. 

 Consequently, I shall in this Paper couflne myself chiefly to 

 the discussion of one subordinate grouj), Ettrytomidus^ first 

 defining and limiting such genera of that grotip as I lind in 

 my collection, and secondly dcsc.riliiug the species in my 

 possession apiiertaining to those genera, with such brief 

 notes on their natural history as I am able to furnish. Of tile 

 other two t'halcidian genera that I shall have occasion to 

 refer to, one is well known to N. A llynienopterists, and the 

 other is a decidedly new and most anomalous and remark- 

 able genus. In the latter case, I shall, of course, be com- 

 pelled to publish a new generic name; in the former case, 

 for lack of space to treat the subjeet as it ought to he treated, 

 I shall simply adopt the establisheil nomenclature. 



It will be seen at once, from my notes on the habits of the 

 various species of Eurijtomides , which it will be necessary 

 to describe, that many of these C/ialcis flies are parasitic 

 upon several different species, and that occasionally the very 

 same CItalcit fly is parasitic upon species belonging todill'er- 

 ent Orders. (E. g. Eiirytoma stitdiosa^ Siiy, and Decatoma 

 nubilistigina, n. sp.) In several cases Kurytomidous forni.^*, 

 that appear to belong to the same species, present certain 

 more or less constant difl'erences when they infest diflereiit 

 species of insects. Such forms seem to deserve a distinctive 

 name, which I have accordingly given to them, classifying 

 them as mere varieties. Whether they be really varieties, 

 or whether they be distinct species, dcprnds— according to 

 my views— upon the diflicult and almost insoluble (piestion, 

 whether such so-called varieties attack indiscriminately the 

 diflerent insects upon which the so-called species to which 

 they are referred is found to be parasitic, or whether each of 

 them exclusively attacks the particular insect upon which it 

 is itself found to be parasitic. In the former easel sliouhl 

 cla.s8ify them as varieties, in the latter case as speci(!s; fori 

 have always considered the promiscuous interbreeding of two 

 forms— whether actu.illy ascertained or analogically inferred 

 —as the Irue test of specific identity; and if such so-culled 

 varieties attack iiromiscuously the different insert.^ upon 

 which the whole so-called species is parasitic, the infeniice 

 is that they derive that propensity, by the Law6ofIiihe.it- 

 ance, from interbreeding habitually with the other fonn.s 

 comprehended under the so-called species If, on the other 





FirMttr'B Monograph of CAoicrf..!.. , irablulicil in Ihc liernifji liinKunijc m 

 IMU. under the title of " Iljmenoptcrologiedic Sludicn, P«rt II, Clialeldlilie, 

 Froctotrupli." 



hand, such a so-called variety confines itself exclusively to 

 that particular insect which it is actually found to infest, 

 then I should infer that it can not interbreed habitually with 

 the other forms referred to the same so-called species; be- 

 cause, if it did so, it would inevihibly, by the Laws of 

 Inlieritanoe, acqiure a propensity to attack all the different 

 insects which are attacked by the other forms provisionally 

 referred to the same species Conscriuently, upon this latter 

 supposition, I should pronounce such a so-called variety to 

 he ill reality a distinct species. 



It is a very interesting fact that a Ilymenoptcrous parasite 

 found in Kurope (CAri/«i» ignitn), which is exceedingly vari- 

 able, both in size, in coloring, and in the structural peculi- 

 arities of the four terminal teeth of the abdomen— two of 

 these teeth being in one variety (Jl/eioyic) aclually obsolete— 

 is also exceedingly variable in the groups of insects upon 

 which it is parasitic. Some, for example, attack the genus 

 Odi/nerus (True Wasps), some the genus Ccrceris (Digger 

 Wasps), and some the genus Vcsjm (Social Wasps ) Mr. Freil. 

 Smith Iris suggested, that the variation in size of this C/irijsit 

 is jierhaps due to the variation in size of the larv;e upon 

 which it preys. ♦ May not the structural and oolorational 

 variations, also, be dtie to similar ciiiises, and may there not 

 be distinct races— or, as 1 should call them, distinct species— 

 of this insect, which jirey exclusively or iilniosi exclusi\ely 

 upon distinct groups of Wasps, and have Iraiismitlert such 

 propensities by the laws of inheritance to their descendants? 

 In that case, as well as in the hypothetical cases just now 

 refcn-ed to among the Clialcis flies, we should have Ento- 

 mophagic ^'arictic8 and Entomophagic .Species, strictly an- 

 alagous to what I have described as IMiytophagic Narieties 

 ami I'hytophagic Species. (Proc. Ent. Soc. Phil.,ill., pp. 

 40:!-I30; v., pp. 1!)4-21(;.) 



The club of the Chalcididous antenna appears to be nor- 

 mally connioscd of about tliree connate and otXen more or 

 less confluent joints. Kuropean authors, in describing the 

 number of joints in the ('halcididous antenna, seem to have 

 always counted the typical joints of the club as true joints. 

 This I have never done, 1st, because they really are not true 

 bona, fide joints, and, secondly, because in the same species 

 some specimens look as if they h.id a two-jointed, some as if 

 they had a three-jointed, and some almost as if they had a 

 I'linr-joiiiled club. Uut, lo prevent confusion, after stating 

 I he number ot veri able free joints in the antenna- say, for 

 iiislance, eight— i have always appended the formula "Scajie 

 +iH-i:iub," or "Sc.+li-(-Cl." 



As lo certain very minute joints which certain European 

 authors have described'as existing in certain genera between 

 the pedicel or second joint of Uie antenna, which is generally 

 short, and the generally elongate third joint or first joint of 

 the flagellum; I believe them not to be true horny joints at 

 all, but mere wrinkles of the counicliiig membrane. Cer- 

 tainly, in the typical antenna, whether in Hymeuoptera or In 

 Colcoptera, the third joint is always a more or less elongate 

 joint, and never a very minute one, as is so often the case 

 with the iiedicel or second joint t 



SUBFAMILY EUllYTOMIDES, Westw. 



Collarc very /ong and Iransversc.-quadratCj as in Fiyurc 8, 

 n, c; hind tltiglis not swelled. 



lii'.NUS EuRVTOMA. (Fig. 1 , « § , 6 (f ) Body partially 

 contractile, as in Chrysiriida, with a deep, finely-sculptured 

 groove for the reception of the middle femora, reaching from 

 the base of the middle coxa to a point immediately beneath 



Kntotnototritt^^ Ati 



II Imvc throuRhoiit tliiii Paper ciilcd Uie flrRtnrlonxjotntor the nntrimn 

 ilie ■ ' senile," and coimidcrcd liic '* flB(;ellufn " an conimeneitiK wiih rhc tliinl 

 joint, eallinft tlic Kiiiall accond joint, whenever I have occanlon to Rivo it ii 

 difiUiu'tivc nonie. the '■ ,*>ediccl." J'hia aftrces with bay's dettnition of these 

 tpt that hetreata the prominence or "radicle," aa it ta technically 



tiTincd, Iron) which tlie antenna apriii^, as a diathiet joint of the d 

 It nppeara alxo to n{;ree with the tcnninoloBy generally adoutcil l,y vuivoi,- 

 terinla and llylnenopteriaU; at all eveiita, 1 ani informed by Baron Oaten 

 sueken tliat tlie terinn arc dcHiied as above by Sehiodtff so lar as rennrda 

 Colcoptera. But in l>iptera. na 1 an) informed on the aainc authority, the 

 univeraal practice ia to coiiaidcr the first and aeeond Jolnta of the antenna as 

 forming collectively the "scape," instead of calling the first joint alone 

 the scape. 



