510 PROCEEDINGS OF THE NATIONAL MUSEUM. 



Adults. — Unknown. 



In this species, the pupa-aise can easily l)e distinguished l)v the 

 unaided e^^e as a ])lack object surrounded b}" a white ring. The imma- 

 ture forms are found on tlie under sides of the leaves of Quercus 

 agrlfolia and Qaennis densljioi'a; as a rule, the}" are confined to a 

 single tree in each neighborhood where the author has collected them 

 and are not plentiful. The eggs are laid very closely together in 

 irregular patches, each of which contains a greater number than is 

 usual among other species. Apparently" fresh eggs and very small 

 larvjfi were collected in the Ar])oretum, Leland Stanford Junior Uni- 

 versity, on January 23, 1901, but no adults were seen; eggs were 

 again found, together with small larvse, during the last week in May 

 and in June. The writer has kept the pupa- cases in the laboratory 

 for various times since the date of first collection, but has never suc- 

 ceeded in securing the adults, and it has been impossible to obtain 

 verified adults in the field, as the oaks have so many species of 

 Aleyrodes upon them. 



Cotypes.—^o. 7091, U.S.N.M. 



Collected ])y Mr. G. H. Coleman near the head of Big River, 

 Mendocino County, June 6, 1901, and by the author in the Santa Clara 

 Valley and on the slopes of Black and King's mountains at various 

 times during 1901 and 1902. 



29. ALEYRODES INTERROGATIONIS, new species. 

 Plate XXVIII, figs. 10-12. 



Egg. — 0.15 by 0.07 mm. : oval; yellow; unmarked. Pedicel at one 

 side of center of base. 



Larva. — (Stage 1.) Elliptical; brownish yellow; margm with lat- 

 eral hairs; dorsum convex. 



Larva. — (Stage 2.) Color yellow; dorsum convex; marginal crenu- 

 lations irregular, shallow, and rounded; abdominal segments distinct; 

 vasiform orifice as in pupa-case, but the operculum is nearly circular. 

 On the dorsum, the su])marginal hairs, the bases of the caudo-lateral, 

 and the cephalic pairs of spines are present. 



Larva. — Size, 0.57 by 0,35 mm.; essentially as in pupa-case. 



Pupa-case. — Size, 0,7 by 0.1 mm,; elliptical; the outer part of the 

 case pale amber; over the bodj^ of the developing pupa^the color is a 

 deeper yellow, sometimes brownish. There is no lateral fringe, in 

 the usual sense of the term, but around the case is a wide, sloping 

 ring of white or ^^ellowish, translucent, gelatinous substance upon 

 which the case rests. In the mass, the substance seems structureless, 

 but when it is mounted in Canada balsam and examined under the 

 microscope while it is dissolving, the rod-like structure is plainl}" 

 seen. In a few specimens there seemed to be a true fringe overlying 

 the gelatinous wax; this was transparent and apparently of separate, 



