1888.] 43 



The most useful works upou the subject will, I think, be found 

 to be Signoret's "Etudes sur les Coccides," first published in the 

 " Annales de la Societe Entoinologique de France," 1868 — 1876 ; 

 Comstock's Reports to the U. S. Agr. Dept. for 1880 and 1883 ; and 

 Maskell's " Coccidse of New Zealand." Targioni-Tozzetti's "Studii 

 sulle Cocciniglie " deals more particularly with the physiological part 

 of the subject, besides which he published a second " Memoria," with 

 Catalogue attached, which, however, does not give a description of the 

 species. Additional valuable information will be found in " L'Ento- 

 mologie Horticole," by Boisduval ; Fitch's first and second Reports 

 on Noxious Insects ; Harris' " Treatise on Insects Injurious to Vegeta- 

 tion." Reference should also be made to the general works of Reaumur, 

 Geoffroy, Burmeister, and Westwood, likewise to papers by Ruricola 

 (J. Curtis) scattered through the early volumes (especially 1843) of 

 the " Gardeners' Chronicle," also to articles by Boucke in the " Natur- 

 geschichte der Insekten" for 1834, &c, and in the " Entomologische 

 Zeitung," 1844 and 1851. There are other papers on the subject 

 mentioned in Signoret's list of the Bibliography of the Coccides, to 

 which I have not had opportunity of referring. There does not appear 

 to be any complete British work upon the subject. 



Many of the Goccidce are almost microscopical, or at least only 

 noticeable by those accustomed to search for them, for they often very 

 closely resemble the colour of the bark to which they are attached, but 

 others are large comparatively. With the aid of a hand-lens much 

 may be done, I think, in the way of collecting and determining the 

 genus, as well as noting the food-plant, and even to' a great extent 

 studying the habits and life history of the insect. For a determination 

 of the species, it is generally necessary to resort to the microscope, 

 for which purpose it will usually be found convenient to subject the 

 insect to the action of some re-agent, and subsequently to mount in 

 balsam, after the usual preparatory treatment. I have also found 

 slight staining useful in some cases. For microscopical treatment, the 

 insects which have been preserved in the cabinet for a year or more, 

 are equally serviceable with fresh specimens. 



Some of the earlier writers (such as Burmeister) appear to have 

 included Aleurodes with the Coccidce, but I believe that it is now 

 generally considered that the true Coccid has only one claw to the 

 tarsus, that the females are apterous, whilst the males are dipterous, 

 having besides the two wings two balancers, one on each side, termi- 

 nated by a hooked bristle, which Comstock notices (Rep. U. S. A., 

 1880, p. 277) fits in to the hem of the wing, after the manner of insects 



