39 



CHIONASPIS WISTARIAE. 



Chionaspis wistariae Cooley, Can. Ent., Vol. XXIX., p. 280 (1897). 

 Chionaspis wistariae Berlese, Rivista di Patologia Vegetale, Vol. VI., 

 p. 379 (1898). 



SCALE OF FEMALE. Plate 2, Fig. 5. Length, 1.8 2.3 mm. 

 Plainly broadened posteriorly, rather thin in texture, dirty white in 

 color. Exuviae .8 mm. long, brown. 



FEMALE. Plate 7, Fig. 7. Median lobes larger and more conspic- 

 uous in proportion to the other lobes than is usual in this genus ; 

 usually parallel in general direction, though sometimes slightly diverg- 

 ent : rounded or indistinctly pointed at the extremities, firmly united 

 at their bases, the chitinous thickened process which unites them 

 extending anteriorly for a distance about equal to the length of the 

 lobes. Second pair distinct and entire but much smaller than the 

 median pair ; outer lobule smallerthan the inner. Third pair usually 

 obsolete but sometimes represented by low, serrate prominences. 

 The gland-spines are arranged as follows: i, i, i, i, 1-2, 2-4. The 

 first one is short and blunt, scarcely surpassing the median lobes. 

 Second row of dorsal gland-orifices represented only by the anterior 

 group consisting of 2 3 orifices. Third row with 3 4 orifices in 

 the anterior and 4 5 in the posterior group. Fourth row with 3 4 

 orifices in the anterior and 4 6 in the posterior group. Median 

 group of circumgenital gland-orifices, 8 15 ; anterior laterals, 19 31; 

 posterior laterals, 13 23. 



SCALE OF MALE. Plate 2, Fig. 5 A. Length, about i mm. Sides 

 nearly parallel, distinctly tri-carinate. Exuvia yellowish-brown, 

 occupying about one-third of the length of the scale. 



REMARKS. 



This insect is readily distinguished from all others of the genus 

 by the median lobes. The only insect which approaches it is C. 

 platani but in that species the median lobes are longer and more 

 plainly serrate. In C. wistariae the male scale is very plainly cari- 

 nated. while in C. platani it is very feebly carinated or without 

 carinae. 



