CADDIS FLY LARVAE—FLINT 469 
An adequate description of the larva of this species was published 
as early as 1921. The larvae may be recognized from existing descrip- 
tions; male metamorphotypes collected in many locations supplied 
additional proof of the correctness of the association of stages. The 
larvae of this ubiquitous form may be easily recognized by the striking 
pattern of the head and pronotum and the apicolateral spur on the 
anal prolegs. 
Description: Length, 25mm. Head, brownish yellow, with a black 
band along the anterior margin, and an irregular W-shaped dark 
brown band posteriorly (fig. 1,c); second segment of maxillary palpus 
about twice as long as first; mandibles edentate (fig. 1,2). Thorax, 
pronotum brownish yellow, with a brown band along anterior margin 
and on posterior half; fore femora considerably broadened. Abdomen, 
anal proleg with basoventral hook and apicolateral spur; claw with 1 
small and 2 large ventral teeth (fig. 1,5). 
Material examined: Many larvae and pupae from various localities 
in Georgia, Maine, Massachusetts, New Hampshire, New York, 
North Carolina, Ontario, South Carolina, and Virginia. 
Remarks: The larvae of fuscula may be found in almost any 
running water that is cool and unpolluted. They have not been 
found in the smallest spring runs, but otherwise are found under 
rocks in riffles of streams as much as 10 yards or more in width. 
The adults have a long flight period—from June into September— 
with the peak of abundance in late June or July. Correlated with the 
long emergence period of the adults is the variation in size of the 
larvae that are collected at any one time, especially in the fall and 
early spring. The species overwinters as developing larvae. 
Rhyacophila torva Hagen 
Figure 2 
Rhyacophila torva Hagen, 1861, p. 296.—Ross, 1956, p. 77 (male genitalia). 
The species torva is quite widespread, in the eastern region, but 
rarely abundant; it is known from the District of Columbia, Maine, 
Massachusetts, New Hampshire, New Jersey, New York, North Caro- 
lina, Tennessee, and Virginia. 
Male metamorphotypes from North Carolina and Massachusetts 
established the identity of the larvae of this species. Both Vorhies 
(1909) and Lloyd (1921) described larvae that they assigned to this 
species; however, the larvae they described were not of torva, but of 
a species close to wibox Milne. The coloration of the head, especially 
of the dark V posteriorly on the frontoclypeus, the edentate mandibles, 
and the structure of the anal proleg combine to make this larva easily 
recognized. 
