YUCCA MOTH AND YUCCA POLLINATION. 145 
THE SPECIES OF PRODOXUS. 
It is my design to give here descriptions of all the species 
so far as known. The early stages of these different species 
are remarkably similar and it is extremely difficult — at 
times quite impossible — to point out characters by which 
to separate them. It will be well, therefore, first of all to 
reproduce the original description of Prodoxus decipiens, 
somewhat amplified, and merely describe the others by 
comparison. The ovipositor varies in appearance according 
as it is extruded or not. 
Generic CHARACTERS OF PRODOXUS. 
Imaco.—Agreeing with Pronuba, except in the following important 
particulars: The basal joint of the maxillary palpi in the female is not 
produced into a spinous tentacle, but is formed just as in the male, being 
a mere blunt-pointed tubercle. 
Larva. — Apodous. 
CurYSALIS. — Without prominent dorsal spines. 
PRODOXUS DECIPIENS Riley, 
[Pl. 39, Figs. 1, 2, 3, 4.] 
Eaa.—Soft, white, easily yielding to pressure, and hence variable in 
shape, but usually elongate, rounded at both ends about 0.4 mm. in 
length, and Jess than 0.1 mm. wide. 
Larva (Pl. 39, Fig. 1, @).—Length 5 to 7 mm. Apodous, plump, 
broadest on joints 2 and 3, tapering thence posteriorly, with the dorsum 
strongly arched and the head and prothoracic joint more or less fully 
bent down on the breast. The body is glabrous and not conspicuously 
wrinkled and the generalaspect strongly recalls some Hymenopterous or 
Rhyncophorous larve. Head small, retractile. Stigmata placed as in 
Pronuba, 7. e., the first pair on the hind portion of the prothorax and 
rather lower down than the succeeding 8 pairs, which are on the anterior 
portion of joints 4 to 11, the prothoracic spiracles somewhat larger than 
the rest. Color of body either pale yellowish-white, or emerald-green, 
this last being the more usual color of the mature and especially of 
the hibernating specimens. The head is honey-yellow with a dusky spot 
on each side, a dash on each suture of the epistoma, the mouth dark 
brown, the mandibles black, labium and maxille white; the mandibles 
have four teeth, much blunter than in Pronuba, though the labial palpi 
are smaller and more plump and the labium and maxillae do not surpass 
the mandibles. The cervical shield is not defined as in Pronuba, but 
consists of 4 chitinous patches of the same color as the head. 
CurysaLis (Pl. 89, Fig. 1, ¢).— Average length about 6 mm. Of 
the same color as in Pronuba but much more slender, with the dorsum 
less arched and lacking the characteristic dorsal, arcuated plates with 
their peculiar recurved, flattened spines, there being in place of them the 
barest indication of a transverse row of minute points or teeth not re- 
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