28 



In a few families a narrow strip of the metathoracic wings is visible 

 on the ventral surface caiidad of the mesothoracic wings (Figs, i, 8, 

 19; W2). 



THE ABDOMEN 



The abdomen consists of ten segments, of which three, segments 

 8-10, are always "fixed"; that is, they possess no power of indepen- 

 dent motion. In the generalized forms motion is possible between all 

 of the other segments. A segment is said to be movable when there is 

 movement between its caudal margin and the segment caudad of it. 

 In many pupae the movable segments are capable of being telescoped 

 so that only their caudal margins are visible. When the cephalic 

 margin of a movable segment is referred to, it includes the rounded 

 part of the segment which is covered by the transverse conjunctiva 

 when the segments are retracted, or telescoped. 



Proleg Scars. — The scars of the larval prolegs are found on the 

 ventral surface near the meson (Fig. 11, psc) and are often conspic- 

 uous. 



Tubercle Scars. — Those families in which the larvae have promi- 

 nent tubercles show very definite scars in the pupae. These are espe- 

 cially noticeable in the Saturniidae. 



Setae. — There are usually setae present on the abdomen, and they 

 are arranged much as are those of the larvae. They are often very in- 

 conspicuous, otherwise they might furnish good taxonomic characters. 

 There is often a dense covering of secondary setae over the entire sur- 

 face, as in some gelechiids and lasiocampids. The Pterophoridae re- 

 tain a spiny armature similar to that found in the larvae. 



Spines. — These are found covering the dorsum of the abdomen 

 in generalized pupae (Fig. 49), and larger ones are also found at the 

 caudal end of the body (Figs. 27, 31 ). They are arranged in rows on 

 the segments in Tineoidea and Tortricoidea (Figs. 27, 31, 39, 41). 



Flanged Plates. — The flanged plates are best developed in the 

 pupae of borers, but are found in other pupae as well. Figure 9 shows 

 them well developed on the dorsum and also shows a well-developed 

 ventral plate on the seventh segment. They are usually developed 

 along the cephalic margin of the segment and prevent the telescoping 

 of the segments. 



Genital Openings. — In the male the genital opening is situated on 

 the ventro-meson of the ninth abdominal segment. It is usually either 

 a mere slit-like opening as in Figure 5, without any adjacent eleva- 

 tions, or it has a distinctly elevated tubercle on each side as in Figure 

 8, go, and occasionally is situated in a slight depression. In the fe- 

 males there are two openings which may or may not become con- 



