VOL. XIV 

 1831. 



] PROOKEDIXCS or THE NATIONAL NirSElTM. 571 



McJitfohia is reared in I'hirope from the cells of Oihjncntu, Tnjpo.ri/lon, 

 Osmin, Stelis, Chal'uoiJoma^ and other bee j^encra, but is also a hyjuM- 

 l)aiasite, preying' upon larvib of Leucospis and MnnoilDntomcnis. Species 

 of this fjenns are found in thisc(^untry parasitic in the nests of Majacltile, 

 Ccrafina, Anthophoni, and I'vlopdus. 



Chalcidid parasites of the lieiuiptera-llcteroptera arc very rare, the 

 only ones being the eupelniincs whic-h infest the eggs of these insects, 

 and a few species of Encyrtus which have the same liabit. Even these 

 are not so abundant, liowever, as the proctotrypid parasites of the same 

 eggs. With the Ileniipteralloinoptera, liowever, they are very numer- 

 ous, although the insects of the homoi)terous families Cic(((li(h(., Fuhjo- 

 ridt(\ Mcml}yacida\ Ccreophhr, and Jassidd are singularly free from the 

 attacks of hymenopterous parasites. Some of tliem are preyed upon i)y 

 the externally attached larvie of the proctotrypid subfamily Jtryininw, 

 but the only chalcidids which I know to attack members of this section 

 are a trichogrammine, forming a new genus, which infests the eg<XA of 

 the buffalo tree-hopper {Geresa huhalns), in the United States, and a 

 species of Eupclmus which is said to inhabit the eggs of Cicada in 

 Europe. The gall-making Psi/llida' are attacked by several species of 

 EnryrtKn, while the Aleyrodidir are attacked by the encyrtine genus 

 Thys((nus, the aphelinine genus Enrarsia and the tetrastichine genus 

 Gyrolasia. The most abundant parasites of the latter insects, liowever, 

 are the exceedingly minute species of the family Mymarida\ When we 

 come to the family Coccidw we find that its si)ecies are infested almost 

 exclusively by chalcidids. The species of one entire subfamily, the 

 AphcUnino), are bark-louse parasites with the exception of a very few 

 species which attack aphidids and aleyrodids. They seem to be con- 

 tiiu'd mainly to the true scale-bearers {Dia.spina), but a few infest the 

 naked bark lice. The latter, however, are most extensively parasitized 

 l)y members of the subfamily Encyrtina\ Hardly a species of scale in- 

 sect can be found which does not have its formidable parasite in some 

 species of one of these two subfamilies, while many of them are also at- 

 tacked by species oi Mymar'uhv which I take, from their minute size to 

 be Ggg parasites in many if not most instances. Outside of these three 

 groups almost no parasites ofCocridn' areknown, the s|)ecies of the genera 

 DUophoiiaater and Ophelosia, provisionally i>laeed in the subfamily /'»- 

 rcniiuv, forming the juincipal exceptions. It is true that an occasional 

 rteromalus or Tctrastichus is reared from barklice and one or two other 

 genera are mentioned in the European lists, but I thiidc it quite likely 

 that most of these forms are hyperi)arasitic and that they have really 

 developed upon some primary encyrtine. 



The most important of the parasites of the Ajihididn or plant lice are 

 the braconids of the subfamily Aphidiina\ but the i)lant liee have many 

 proctotrypid parasites (all belonging to the subfamily Cr>7r/»Aro»fH/() a,s 

 well as many among ihi.' CItalcidida: Besides the fewaplielinines there 

 are a number of species of the subfamily Ptcromaliiui, particularly those 



