ALEURODICUS COCOIS. 53 



ent species. On the other hand, we have specimens from the Canal 

 Zone in which the pupa cases are of quite a different form from the 

 usual type, being broader. There appear three varieties, one with a 

 large and comparativelj'^ elongate pupa, one with a small elongate 

 pupa, and one with a broad pupa. In these there appear no struc- 

 tural differences. The larger material, that which we might call the 

 rndefieens material, has an average of 1.22 mm. by 0.92 mm., the 

 smaller material an average of 1.06 mm. by 0.75 mm., while the Canal 

 Zone material, lot No. 0708, has an average of 1 mm. by 0.89 mm. 

 The largest specimen found in any material was 1.2G mm. by 0.98 mm. 

 and the smallest 0.98 mm. by 0.7 mm. 



The arrangement of the pupa? upon the leaf in reference to the 

 median vein and the waxy secretion developed about them is similar 

 in CockerelTs type of irklescem and in eocois (PI. XIV, fig. 1). The 

 difference in host would easily account for the slight difference seen. 



Adults. — Some variation is shown in the adults, first, as to size and, 

 secondly, as to wing marking. The type of Cockerell's iridescenj^ in 

 the U. S. National Museum collection is a small male and will be 

 discussed under that sex. The vertex (PI. XII, fig. 11) is rounded 

 and the antennae (PI. XII, fig. 12) are of seven segments, not six, 

 as stated by Riley and Howard. Segment III is much the longer; 

 II, IV, and V nearly equal in length, while VI and VII are some- 

 what shorter. All the segments are imbricated, and V and VII are 

 armed with fringed sensoria. The paronychium of the foot is the 

 usual spine, and the basal segment of the tarsus is nearly twice as 

 long as the distal one. The f orewings are armed on the costal margin 

 (PI. XII, fig. 9) with conical hair}' projections and two alternate 

 rows of large bristle-like hairs. The remainder of the margin (PL 

 XII, fig. 10) lacks these hairs. The wings are marked with two 

 dusky patches, one from the costal margin crossing the radial fork 

 and the other at the distal extremity of the wing. In most forms 

 these patches, especially the distal one, are very indistinct, but many 

 degrees of intensity of shading occur, and in specimens from Pro- 

 greso, Yucatan, lot No. 328G, the clouding is quite marked. Some 

 dry specimens in which we were not able to distinguish any marking 

 showed it quite plainly when balsam mounts were made. 



The female genitalia are of the ordinary Aleurodicus type. The 

 forewing is 2,15 mm. by 1.15 mm., the hind tibioe 0.77 mm., and the 

 tarsi together 0.307 mm. 



The males show a great range in size. This is shown in a compara- 

 tive measurement of parts. The type of IrUIescens has claspers 0.4 

 mm. long, and the width of the genital segment is 0.22 mm. In ma- 

 terial of eocois., from different regions and hosts, a range from 0.4 

 mm. to 0.92 mm. is met with in the claspers, depending upon the 

 size of the individual. The average seems to be nearly 0.8 mm. In 



