NO. 1362. ALF.YRODIDS OF CALIFORNIA— BEMIS. 473 



The adults may roadily be found rcstino- on the under sides of the 

 leaves. In colU'eting-, if the adults take to Hl.g'ht, it is only necessary 

 to remain (|uietly iti wait, for they usuall}' return from this upward 

 flight, alighting in almost the same places from which thej^ arose; the 

 author has frequently tluis disturl)ed a femal(> in the act of egg-laying, 

 and has seen her return to the same leaf when the disturbance ceased. 

 The sure method of securing adults is, of course, to breed them from 

 pupa' which have been carefully isolated. 



All the species described have been placed in the genus Aleyrodes. 

 Where the author has described species from immature forms only (a 

 usage adopted by systematic students of this family from the begin- 

 ning), there was no means of definite generic identitication, as the 

 generic characters lie in the wnng venation of the adult. But as all 

 the adults found belonged to Aleyrodes it was deemed best to place all 

 forms examined provisionally under the one genus. 



The author has had to depend on the pupa-cases for the identitication 

 of species, there being very little specific dift'erence in th(^ adults. 

 True, some have such distinct characters as immaculate wings and y^X- 

 low body, but there are others with similarly unmarked wings in which 

 the abdomen is yellow and the head and thorax brownish, while still 

 others have wings bearing dusky spots and the l)odies with regular 

 dark-brown markings. But as apparently identical adults issue from 

 widely difl'erent pupa-cases, even the constant adult characters have no 

 systematic value unless correlated with the pupal characters. 



In the determination of the adults here described the specimens in 

 question have in every case been bred b}' the author from their pupa? 

 in the laboratory, or taken out of doors in the act of issuing from the 

 pupa-case. In the determination of larval stages the following precau- 

 tions have been taken for securing accurac}': In determining the begin- 

 ning of the tirst stage the author has used onh' specimens obtained b}^ 

 capturing the larvie immediateh' upon their issuance from the eggs. 

 In determining later stages advantage has l)een taken of the insects' 

 ha])it of preserving the larval moults, which may be found on the dor- 

 sum in regular succession from the first to the latest, which rests imme- 

 diately upon the dorsum of the pupa-case. These moults have ))een 

 removed, mounted in glycerin jelly or in Canada balsam, their charac- 

 ters studied and their dimensions taken from comparison with identical 

 stages found on the same leaf. 



The following new^ species included in this paper, all from Califor- 

 nia, are described under the following names: Alej/rodes nxtdron!, A. 

 sjjlendois, A. q^iaintancei, A. sta»fo7'di,, A. et^rans, A. ititen'ogatioius, 

 A. QnaKl'elli^ A. dlasemus^ A. extra /n'ens, A. merlin i, A. tn'/h/iatue, A. 

 am?iic()h(^ ^[. jmiinostis, A. ///y/v//;.v, ^1. /'r/'dcscefix^ A. tentdoddta.s^ A. 

 hell <)</(/ i^ A. hiifchhujsl , and ^1. <ilaci(d >x. 



The Alevrodidie taken in California have ])een found t>n the follow- 



