some new Coccidse. 25 



Aspidiotus yuccarum, sp. n. 



? . — Scale circular to suboval, about 2| millim. diam., 

 slightly convex, dark brown, rough and concentrically 

 wrinkled, blackish towards the middle ; but the central part, 

 covering the exuvise, covered by a large round patch of white 

 secretion ; when this is rubbed off, the exuviae are exposed, 

 shining black, subcentral. There is a thick ventral scale. 

 Young female scales appear entirely white, or, when rubbed, 

 white with a black spot. 



$ .—Scale elongate, brown, with the exuvia at one end 

 covered by white secretion. 



? . — Caudal region brownish ; three pairs of lobes, these 

 short, yellowish brown, notched at the end, with glandular 

 processes at their bases much as in Diaspidiotus ; the middle 

 lobes especially remind one of human premolar teeth, fangs 

 and all. Middle lobes a short distance apart, second separated 

 by a similar distance from the first, third separated from the 

 second by an interval about as great as the width of the 

 former ; margin beyond the third minutely crenulate, with a 

 protuberance representing a rudimentary fourth lobe some- 

 what further from the third than the third is from the first. 

 Spines very minute. No spine-like or other plates. No 

 grouped ventral glands, but many small round or slightly 

 elongate dorsal glands. Anal orifice a long distance from the 

 hind end. Antennas represented by a small tubercle bearing 

 a single bristle. 



Rah. At bases of leaves of Yucca elata, associated with 

 JJactylopius dasylirii, Ckll. (for which the Yucca is a new 

 food-plant), Mesilla Park, a short distance east of the Agri- 

 cultural College, at the beginning of the Larrea zone, May 

 1898. 



This very distinct species belongs to an unnamed section 

 of the genus, allied to Diaspidiotus, containing A . yuccarum, 

 Ckll., A. yuccce, Ckll., and A. bigelovios, Ckll. These species 

 agree in having black exuvige, no plates (gland-hairs), and no 

 grouped ventral glands. A. yuccce was described from 

 Mexico; but on May 19, 1898, Prof. C. H. T. Townsend 

 found it at the bases of leaves of Yucca elata in the Mesilla 

 Valley, New Mexico. This new find shows that the small 

 size of the insect is in no way due to immaturity, for speci- 

 mens of the size of the original types are full of eggs. The 

 living female of yuccw is dull lilac, and it turns bright lemon- 

 yellow in liquor potassas. What I called the spine-like plates 

 in the original description are the true spines; they are much 

 larger than those of yuccarum. The Mesilla- Valley form of 



