402 PROCEEDINGS OF THE NATIOXAL MUSEUM. vol.51. 



Subgenus Aleurothrixus. 



Pupa case with margins usually angled, color variable, margin of 

 case with an apparent double row of teeth, wax tubes well developed; 

 wax secretion fiocculent or woolly; vasiform orifice small, trans- 

 versely elliptic; hngula obscured by operculum. 



Type. — Aleurothrixus {Aleurothrixus) howardi (Quaintance). 



SPECIES OF SUBGENUS ALEUROTHRIXUS. 



1. Pupa case with a row of distinct spines all around case on the sub marginal area 



aepim. 



Pupa case without such row of spines 2. 



2. Pupa case with a row or comb of spinelike projections on the caudal margin of the 



vasifonn orifice howardi. 



Pupa case without such comb of spines 3. 



Spines latero-cephalad of the vasiform orifice and on caudal margin of pupa case 



very long and prominent; color of case varying from yellow to hr own. .Jloccosus. 



3. Spines latero-cephalad of vasiform orifice and those on caudal margin of case short 



and vasifoiTu; color dark brown ported. 



ALEUROTHRIXUS (ALEUROTHRIXUS) AEPIM (Goeldi). 



Plate 62, figs. 1-7. 

 Aleurodes aepim Goeldi, Mitth. Schweiz. Ent. Gesell., vol. 7, 1886, p. 250. 



This species was described from "mandioca doce" at Rio de 

 Janeiro. The one character given in the description which would 

 make the recognition of the species possible is the row of submarginal 

 bristles. In the collection of the Bureau of Entomology there is a 

 species showing submarginal bristles. It was taken on cassava 

 {Manihot utilissima Pohl) at Rio de Janeiro by F. Noack, date 

 unknown. There seems Uttle doubt, therefore, that this is the species 

 described by Goeldi. 



Egg (fig. 1). — Length 0.144 mm.; considerably curved, the stalk 

 arising near the base on the convex side; color yellowish brown, with- 

 out sculpturing. 



Early larva (fig. 2). — Size 0.304 by 0.176 mm.; shape elUptic; 

 dorsum not arched, abdominal segments distinct; median dorsal area 

 with two pairs of vasiform spines similar to those on the larvae of 

 jloccosus; submarginal area with a row of prominent spines which 

 are longer than the vasiform spines on the middle of the dorsum. 

 There are six pairs of these on the thoracic region and only three 

 pairs on the abdominal region of the specimens we have for study. 

 The caudal pair of these is very long and the latero-caudal pair deli- 

 cate. 



Pwpa case (fig. 3) .—Size 0.752 by 0.482 mm. Shape similar to that 

 oi jloccosus; dorsum not arched, but vasiform orifice slightly elevated. 

 Submarginal area with at least eight pairs of prominent spines, six 

 pairs being situated on the thoracic region and two pairs upon the 



