December, '09] JOURNAL OF ECONOMIC ENTOMOLOGY 429 



describe as a new species the colony on the supposedly abnormal food 

 plant. 



Again, variations in size, color and vestiture have misled many to 

 describe a mere variation as a new species or variety. Then, too, it 

 was generally conceded by the early entomologists that the same 

 species of such sedentary insects as coccids could not live on different 

 food plants especially if the hosts belonged to different genera. A sen- 

 tence in Fitch's original note-book expresses his views on this subject, 

 when he describes the common oyster-shell scale as a new species 

 because he found it on the dogwood {Coruus stolonifera), and adds: 

 "Certainly there is the same ground for deeming the species of this 

 genus, which occur upon plants of different genera, to be distinct 

 species, that there is in the genus Lecanium." As the result of this 

 idea, there are more than forty species and many more varieties of the 

 genus Lecanium described in Fitch's note-book; but fortunately the 

 majority of these descriptions never appeared in print. This idea, 

 prevailing in the time of Linnaus, Geoffroy, Gmelin, Modeer, Fab- 

 ricius, Burmeister, Schrank, Bouche and Boisduval, has resulted in the 

 publication of a multitude of descriptions of supposedly new species, 

 many of which have been subsequently reduced to synonymy. Un- 

 fortunately many of these names still remain as valid species in our 

 catalogues; especially in the non-diaspine groups, and more especially 

 those species of the genus Lecanium. Moreover, within the last decade 

 or two, many species have been described and published here and 

 there, from insufficient material, and without the careful study and 

 comparison with other species which are nearly related, and with but 

 little regard for the individual variations which are bound to appear 

 in insects so absolutely dependent upon the kind and condition of 

 their host plants as are the sedentary scale-insects. It is most un- 

 reasonable to expect to find a perfectly formed and fully developed 

 Lecanium or Pulvinaria en a twig or stem of 1-16 inch diameter on 

 a starved plant, when the normal form would appear only on the flat 

 surface of a leaf or a large stem in vigorous growth. Prof. Robert 

 Newstead in his Monograph of the British Coccidse and more recently 

 Dr. Paul Marchal, of Paris, have done some valuable work in the 

 reduction of the synonyms of the early students of scale insects, and 

 there is still much to be done. 



The writer has been especially fortunate during the past five years 

 to have access to the finest collection of Coccidse in the world; a col- 

 lection several times the value of any other in existence on account 

 of the large percentage of type and cotype material; the national 

 collection at Washington at the present time containing upwards of 



