THE COCCIDAE OF SOUTH AFRICA. — III. 210 



Genus Howardia, Berl. & Leon. 

 Scale of adult $ + oval to elongate, with the exuviae at or near one margin of 

 the scale. Scale usually + covered by the outer layers of the bark of the host- 

 plant. PygicUum with median lobes well developed and with a pair of usually 

 clubbed paraphyses. Circumgenital glands usually absent. 



121. Howardia biclavis (Comst.) (Plate xiii, fig. 133). 



Chionaspis (?) biclavis, Comst., Second Rept. Dept. Agr. Cornell Univ. p. 98, 1883. 



Aspidiotus theae, Green, Insect Pests, p. 13, 1890 ($ only). 



Chionaspis biclavis, Craw, Rept. Cal. Bd. Hort. p. 14, 1891 



Howardia biclavis, Berl. & Leon., Riv. Pat. Veg. iv, p. 348, 1896. 



Chionaspis biclavis, Green, Cocc. Ceylon, ii, p. 152, 1899 ; Newst., Mon. Brit. 

 Coccidae, i, p. 190, 1901. 



The original description by Comstock (l.c), omitting figure references, is as- 

 follows : — 



" This species, of which only the female is known, is remarkable on account 

 of its habit of burrowing beneath the epidermal layer of the leaf or twig which it 

 infests. The color of the scale is white ; but this color is almost invariably 

 obscured by the layer of vegetable tissue beneath which the scale is, and which 

 adheres closely to the scale. . . . 



" Scale of female. — The scale of the female is very nearly circular. On this 

 account I place the species inthis genus only provisionally, until the scale of the 

 male is found. The exuviae are marginal and project beyond the edge of the scale, 

 giving the whole scale more nearly the form of Chionaspis than of any other known 

 genus. 



" Female. — The characters presented by the last segment of the female are as 

 unusual as those presented by the scale. The pores on the dorsal surface of the 

 segment are very small. Scattered over the ventral surface are numerous minute 

 spines. The groups of spinnerets are wanting. 



" The mesal lobes are large, oblique ; nearly twice as broad as long ; approximate 

 at the base ; the mesal margins diverge slightly ; distal margin serrate ; meso- 

 distal angle rounded and produced into a lobule. The second lobe is very small, 

 being simply an angular projection of the body-wall. The third lobe is about three 

 times as wide as the second lobe, but it projects only a little beyond the margin 

 of the segment. 



" The plates are simple and spine-like. There are two minute ones between 

 mesal lobes ; two between first and second lobes ; two or three between second 

 and third lobes ; a group of three or four larger ones laterad of third lobe ; and 

 another group of four or five still larger ones about midway between this group and 

 the penultimate segment. Each of the three segments preceding the last bears on 

 each lateral margin about seven plates. 



" Two spines accompany each group of plates, one on the dorsal surface and 

 one on the ventral. The first and second spines of each side are very small ; the 

 third, which is between the second and third lobes, is the largest ; the fourth and 

 fifth are successively smaller. 



