CICADELLINAE: PART 2. NEW WORLD CICADELLINI 7 
small, I have not found the number to be constant, and the illustrations are not 
precise in this respect. 
The form of the male plates, and their chaetotaxy is often useful taxonom- 
ically. The descriptions do not include all the microsetae present on the plates 
unless the latter are important in classification. 
The taxonomically important so-called “internal” genitalia of the males con- 
sist of a pair of symmetrical styles; a structure extending between them near their 
bases, the connective; an intromittent organ, the aedeagus; and in some species 
one or a pair of accessory structures, the paraphyses, arising between the apex of 
the connective and the base of the aedeagus. The ‘‘shank”’ of the style extends 
from its articulation with the connective to the style apex. The form of the styles 
and their extent relative to the apex of the connective are useful characters. Only 
one style of the symmetrical pair is described hereinafter. 
The form of the connective is constant within taxa. Most often it is Y-shaped, 
with the stem of the ‘‘Y”’ almost always bearing a keel in the species included 
here. It has been considered a basal sclerite of the aedeagus by morphologists. 
The paraphyses may be paired or not (paraphysis), symmetrical or asym- 
metrical. Asymmetry may be the result of difference in form, or of two parts lying 
in asymmetrical planes, or of a single paraphysis not lying in the median plane. 
They may articulate with the connective and with the aedeagus or may be 
separate from either or both. 
The aedeagus may articulate at its base with the apex of the connective, or it 
may be widely separated from the latter, often occurring more closely associated 
with the anal tube (abdominal segments X plus XI) than with the connective. 
The aedeagus is nearly always constant in form within a species. Basically, it is 
campaniform. The basal ring is the atrium. Occasionally the atrium has an an- 
terior extension, the preatrium, from its ventral basal portion. The preatrium, 
when present, usually articulates with the connective. The ‘‘shaft” of the 
aedeagus is the part traversed by the gonoduct, and also the part beyond the 
gonopore unless this part appears as a process. Processes may arise from any 
portion of the aedeagus, and are referred to in terms of where they arise (e.g. 
atrial processes, shaft processes). 
Rarely, there may be one or more processes from the anal tube, in the males. 
The abdominal sternum VII of the female may vary from slightly to strongly 
produced posteriorly, and the form of the posterior margin may be useful in 
classification. The form of female abdominal tergum IX, the pygofer, and its 
chaetotaxy are useful characters. The form of the second valvulae of the 
Ovipositor, especially at their apices, and their armature of primary teeth and 
secondary denticles on the dorsal margin has been most helpful in relating the 
genera to one another. It should be noted that in the generic descriptions, the 
characters of the ovipositor are often based on relatively few species, and that the 
size of the small denticles of the second valvulae is often exaggerated in the 
figures. 
Technique 
The technique used for the preparation, study, and preservation of the male 
genitalia has been described by Oman (1949a:21), with some modifications by 
Young and Beirne (1958a:2). 
