68 
Journal of Agricultural Research 
Vol. I, No. i 
The: LARVA (FIG. 5) 
Larva, newly hatched, about 0.12 mm. in length, nearly white, but soon turning 
yellowish. When fully developed, it averages nearly 3 mm. in length, fully extended, 
and is bright translucent yellow, the black, chitin- 
ized mouth parts, tracheal system, and dark con¬ 
tents of the posterior alimentary canal being plainly 
visible through the body walls. Form subacute 
anteriorly, increasing rapidly in diameter caudad 
Fig. s• I#arva of the serpentine leaf- for about one-third of its length, then gradually 
miner, lateral view. Enlarged, diminishing posteriorly to the bases of the anal 
(Origiiial.) spiracles, where the body becomes rather suddenly 
truncate, terminating abruptly. Anal spiracles large, porrect, extending beyond end 
of cauda. Body segments visible and each encircled by a band, granular in appear¬ 
ance, which is sprinkled with minute setaceous tubercles. Anterior 
spiracles much smaller than posterior, somewhat chitinized at tips, 
knobbed, and situated in a slight depression. 
Upon the ventroanal surface there occurs a tubercular, suckerlike 
organ, in addition to which is a pair of rather large ventrolateral 
tubercles placed between the anal spiracles and the organ mentioned 
above. (Description by W. R. Walton.) 
THE PUPARIUM (FIG. 6) 
Puparium slightly less than 2 mm. in length, greatest width about 0.8 
mm. Oblong oval in form, slightly flattened, the sides sinuate or 
fluted in outline. Segments strongly marked. Bright yellow in 
color when freshly pupated, gradually darkening to brown as the 
development of the pupa progresses. Surfaces slightly shining, but 
without sculpture. Anterior and posterior spiracles prominent, as 
shown in figure 6. (Description by W. R. Walton.) 
HIBERNATION 
Mr. George G. Ainslie finds that at Lakeland, Fla., the larvae of the 
serpentine leaf-miner may continue feeding throughout the entire winter. 
They were observed by him mining in cowpeas in January, 1913. In the 
Salt River Valley of Arizona Mr. V. L. Wildermuth finds that during 
mild winters the larvae may mine in the leaves until after Christmas. 
Ordinarily, however, in that locality, the larvae go into hibernation late in 
November. At Brownsville, Tex., although we have no information 
relative to this species, Mr. R. A. Vickery finds that other insects do not 
hibernate at all, which agrees with what Mr. Ainslie observes to be true 
of this species in Florida. 
It would seem, therefore, that the species hibernates north of Florida 
and extreme southern Texas and that, so far as known, hibernation takes 
place only as pupas on or beneath the surface of the soil. In the North 
only a small percentage of the last generation in the fall lives to enter 
hibernation at all, owing to the fact that the larvae continue feeding in 
their mines until late in the autumn, large numbers in this way being 
killed annually by the early freezes of October and November. In the 
Salt Lake Basin in Utah this insect begins to enter hibernation during 
Fig. 6 .—Pupa- 
rium of the 
serpen tine 
lea f-miner, 
ventral 
view. En¬ 
large d . 
(Original.) 
