Economic Impoiicincc of the Parasites of Coccidai. 221 



shown to be of enormous value, though their action is to 

 some extent uncertain. But the internal parasites are less 

 known, and, in fact, have been too much neglected, though 

 a considerable amount of work has been done on tliein in 

 recent years by Dr. L. O. Howard, Mr. Hubbard, and other 

 able American Economic Entomologists. Mr. W. H. 

 Ashmead has also published some valuable work on these 

 parasites, including the " Classification of the old family 

 Chalcididm" * and a paper " On the genera of the Chalcid 

 flies belonging to the sub-family Encyrtinx!' f In the 

 latter work he gives the host, or hosts, of each species, 

 which much enhances the importance and value of the 

 paper. 



A very interesting characteristic of some of these para- 

 sites is that they will attack more than one species of scale, 

 which makes them especially valuable from the economic 

 point of view. Information as to this may be found in 

 Mr. Ashmead's second paper referred to above, but experi- 

 ments are urgently needed to ascertain what parasites are 

 likely to be most valuable on this account. Among those 

 that attack more than one host, Ashmead mentions 

 Encyrtus infidus Rossi, A'phycus Iccanvi Howard, Blasto- 

 thrix sericea Dalman, Microterys chalcostomus Dalman, 

 M. fuscipennis Dalman, M. flavus Howard, 31. sylvins 

 Dalman, Arrhcnophagus chionaspidis, and Signiphora 

 flavopalliata Ashmead, giving the hosts of each. 



A case of considerable interest has lately been recorded 

 by the Economic Entomologists, Koningsberger and Zim- 

 merman, in their work on the enemies of coffee-culture in 

 Java ; they found that Lccanium viride, a highly injurious 

 scale, is kept in check by the Hymenopterous parasite, 

 Encyj'tus logoricnsis. It is worthy of remark that this im- 

 portant and interesting relation has only been discovered 

 within the last few years, and we may confidently aiitici- 

 pate that other parallel cases will soon be added to those 

 already brought to light. 



The fact that comparatively little is known about these 

 parasites is scarcely a matter for surprise, for it must be 

 remembered that the existence of these enemies is only 

 obvious to the trained observer. A colony of scales may 

 be thoroughly parasitized so that every individual is 

 doomed, and yet to the unskilled eye there exists no 



* P. Ent. Soc, Washington, iv, 3, pp. 242-249. 

 \ P. U. S, Nat. Muf?., xxii, pp. 323-412, 



