256 



COOCID^ OR SCALE INSECTS.- IX. 



By T. D. A. Cock.er.ell, Honorary Entomologist of the New Mexico 

 Agricultural Experiment Station. 

 ( Continued from Bulletin Jan., 1896 ). 

 Genus Lecanium. (Shield-scales.) 

 (52.) Lecanium nigrum, Nietner. (Black scale of India.) 

 Mr. Fawcett has sent me specimens of this species on leaves of teak, 

 from Hope Gardens, Jam dca, in June, 1896. They are accompanied by 

 the usual black fungus. This is, if I remember right, the first scale re- 

 corded from teak, and anything relating to that tree is of special in- 

 terest at this time, in view of the admirable articles by Sir D. Brandis 

 on the Teak Forests of Burma, appearing in " Garden and Forest/' 

 The scale is a common East Indian species, and has bee a introduced 

 into Jamaica, doubtless, on teak or some other East Indian plant. See 

 under L. depressum. Bull. Bot. Dep. Jamaica May 1894, p. 70. 



Genus Howardia. 



Messrs. Berlese and Leonardi have lately proposed the generic name 

 Howardia for three species, H. biclavis (Comst ), H. citri (Comst.) and 

 H. elegans, Leon. The generic character they assign, — the absence of 

 the grouped glands — is certainly not of generic value, and they do not 

 state which of the three species is the type of the new genus. I will 

 therefore take for the type of Howardia the first mentioned species, the 

 Chionaspis biclavis of Comstock, which I have long felt ought to be 

 separated from Chionaspis. The second species, citri, will fall in anew 

 subgenus of Chionaspis, which may hereafter be regarded as a distinct 

 genus. The third, H. e'egans, seems to be an Aulacaspis, but unfor- 

 tunately the male scale is unknown 



(53.) Howardia biclavis, Comst. (The Burrowing Scale.) 



Diagnosis. — A small, nearly circular scale, which is covered by the 

 epidermis of the twigs on which it occurs, so as to be extremely incon- 

 spicuous. Maskell describes a variety from the Sandwich Is. which 

 is not covered by the epidermis. The species is easily recognised on 

 microscopical examination by a pair of club-shaped organs, directed 

 inwards, at the hind extremity of the female. 



Diitribution. — Mr. Hart has found it on Flacourtia in Trinidad, but 

 this is the only record for the West Indies. Elsewhere, it occurs on 

 hothouse plants in the city of Washington (Comstock), in the Sand- 

 wich Is. (Koebele), in Tahiti and Mexico (Craw), and in Ceylon (Green), 



Food-plants. — Various ; flacourtia, Cinchona, tea, coffee, Grevillea. 

 orange, lime, Diospyros, Ficus, Tamarindus, Achras, Eloeocarpus. 



Destructiveness. — Mr. Green, writing of its occurrence in Ceylon, 

 says, " Very common on stems of Cinchona and Tea, sometimes in 

 such numbers as to considerably injure the plants." It is also impor- 

 tant to note that it attacks Citrus trees. Being so extremely incon- 

 spicuous, it may become abundant before its presence is suspected. 

 Genus Chionaspis. (The Snow- scales). 

 (54.) Chionaspis citri, Comst. (The Orange Snow-scale). 



Diagnosis. — The female scales are small, elongated, of a blackish- 

 brown color ; their very dark color distinguishes them at once from 

 other West Indian species of the genus. The male s 'ales are very 

 .small, white, and occur in great numbers, so that the trees somtime 

 look as if they had been whitewashed. 



