INSECT ENEMIES OF WESTERN FORESTS 61 
bb. Caterpillars travelling with a loop- 
ing motion; with three pairs of 
true legs in front and two or 
three pairs of prolegs in the rear. 
loopers or measuring worms, page 74. 
ce. Olive-green caterpillars with black 
and yellow stripes on top and 
sides, brown or red heads; feed- 
ing on California oaks. 
California oak worm, page 68. 
(2) Caterpillars very hairy. 
aa. Caterpillars brightly marked with 
blue, red, or yellow spots and 
long pencils or distinct tufts of 
hairs like a toothbrush. 
tussock moths, page 69. 
bb. Caterpillars of dull colors, black, 
and yellow, feeding in masses on 
terminal branches. 
tiger moths, page 66. 
cc. Blackish eaterpillars with row of 
nearly square, white blotches 
along the back, irregular white 
marks along the sides, and brown 
spines and longer, paler hairs. 
Feeding on poplar and willow. \ 
satin moth, page 72. be 
2. Leaves chewed, but defoliated part of tree not covered with 
silken webbing. 
a. Work done by caterpillars with seattered’ spines or 
hairs; three pairs of front legs, four pairs of 
median prolegs, and one pair of anal larvapods. 
(1) Yellowish-green or brown, leathery cater- 
pillars with short dark hairs and seven 
or eight stout branched spines on nearly 
every segment; feeding on ponderosa pine. 
pandora moth, page 64. 
(2) Black caterpillars with fine, branched spines 
on each segment, middle row of spines 
bright yellow; feeding on _ species of 
Ceanothus. 
California tortoise shell butterfly, page 165. 
(3) Large, stout caterpillars with sparse, stout 
tubercles; feeding on broadleaved trees 
DTN ES STAT LIS oat so a ee ya giant silk moths. 
(4) Yellow and black caterpillars with branched 
Spines; feeding on willow, popular, and 
other broadleaved trees and_ shrubs 
brown day moth. 
b. Work done by naked slugs with three pairs of true 
legs and six to eight pairs of prolegs; sometimes 
covered with slime; one end of body frequently 
held in midair when disturbed______~_ sawflies, page 87. 
3. Leaves mined internally. 
a. Working inside of coniferous needles 
needle miners, page 85. 
b. Working in broad leaves_____________ leaf miners, page 86. 
4. Leaves skeletonized, with midribs and veins still evident. 
a. Work on broadleaved trees done by active grubs 
with three pairs of true legs, or by hard-shelled 
ro see = = 
beetles Shee Waa TU ed leaf beetles, page 92. 
B. Trees sickly, leaves not chewed but yellowing or covered with a sticky 
extldanronyorblacksmut. we as sap-sucking insects, page 44. 
Greaves; stumped called. or swollen. 9.922) 3 gall makers, page 52. 
_*Similar work is done on broadleaved trees by a great variety of caterpillars, saw- 
Hie, ue and to be certain of the insect responsible, specimens must be captured and 
identified. 
