Dactylopiince. 357 



Genus DACTYLOPIUS, Costa. 

 Dactylopiiis, Costa, Fauna del Regno di Napoli, Vol. VI. p. 15, 1856. 



Sorely against my inclination, I have resigned myself to the adoption of the 

 above name for the 'Cochineal Insects,' in place of the more widely accepted 

 name of Coccus. It is hard to part company with old friends, and ever since I 

 commenced the study of the Coccidae I have been accustomed to regard the 

 name of Coccus cacti as that of the type of the whole family. Now, alas, both the 

 generic and the specific name of the typical Cochineal insect have to be aban- 

 doned, and that insect must be referred to as Dactylopius coccus. As noted by 

 Prof Newstead {Monograph of the British Coccidce, Vol. II. p. 256), Prof. 

 Cockerell has made it quite clear that Dactylopius coccus is the first available 

 name of the commercial Cochineal Insect. 



Species of this genus are distinguished from most other ' mealy bugs' by the 

 presence, in their bodies, of a rich crimson dye which exudes from the fresh 

 insects when they are crushed, or may be extracted from the dried insects by 

 boiling. They have no setiferous anal ring. The derm is characterised by the 

 presence of irregular clusters of circular ceriferous pores and truncate spines, 

 thjC latter being particularly numerous and conspicuous on the wild forms, but 

 sparse and small on the cultivated species. The antennae are comparatively 

 short and tapering ; they are normally seven-jointed, but the joints are often 

 confused, and some of them are usually reduced to narrow rings. The female 

 insects secrete a considerable quantity of white mealy or tomentose matter. 

 The males undergo their transformations in an elongated felted or tomentose 

 sac. In some species both alate and apterous forms of the male are produced. 



The several species are restricted to plants of the genus Opuntia. One 

 species only {D. indicus) occurs in Ceylon. 



For a description of the various forms and their claim to specific rank, the 

 reader may refer to my paper ' On the Cultivated and Wild Forms of Cochineal 

 Insects' {Journ. Econ. Biol.,Wo\. VII. Pt. 3, p. 79, Sept. 1912). Alluding to the 

 wild forms, I have there remarked that 'it must be confessed that a careful study 

 of them reveals no sharp characters by which they may be defined. I am inclined 

 to regard all these wild forms as comparatively recent derivations oi tomentosus, 

 differing but slightly in the proportions of the limbs and the shape of the truncate 

 spines. The Indian and African forms were almost certainly introduced from 

 the Neotropical regions of America, and may have become differentiated under 

 the altered conditions. Coccus cacti {Dactylopius coccus)^ on the other hand, has 

 characters so distinct as to make it probable that its segregation dates from a 

 much earlier period.' 



The cultivation of the Cochineal Insect was a thriving and profitable in- 

 dustry until it was ruined by the discovery of analine dyes. A certain amount 

 of genuine Cochineal is still employed for dyeing special goods, also as a 

 colouring matter for culinary and medicinal purposes. 



