76 
than the other species of this group. It has at times been extremely 
abundant and an orange pest of much importance. An article on the 
species from an economic view is found in the Report of the Ento- 
mologist for L889. They occur on the under surface of the leaves; the 
eggs are colorless or pah 1 greenish-yellow 
Tetranychus desertorum n. sp. 
Dark red, with black spots along each side, and a central spot before 
the middle; legs pale. Body quite broad, with the usual bristles, the 
frontal pair about one-half as long as the sub- 
frontal. The palpi are longer than usual; 
there is a spur on the tibia of male as usual; 
the thumb not as long as claw and with three 
slender lingers on the tip, the middle one (seen 
from the side) is the largest. The mandibular 
plate is long and slender, narrowed toward 
tip; at middle of tip a small but distinct deep 
notch; stylet below the plate appears to be 
cleft only for a short distance. The legs are 
quite stout, the femur I more than twice as 
long as broad; tibia I plainly longer than 
patella I; tarsus slender, ending in a claw, 
which is strongly bent near middle and four- 
cleft beyond. 
Specimens come from Mesilla Park, N. Mex., 
on Larrea tridmtata and Phacelia <T< inihit<t. It is closely allied to the 
other species of this group, but the plate is more tapering than usual. 
Tetranychus gloveri n. sp. 
Red. with irregular dark confluent spots each side of body; legs 
yellowish. The body, though broad at the shoulders, tapers behind 
even in the female; bristles long and 
fine, the subfrontal pair more than twice 
the length of the frontal pair; all in the 
usual arrangement. The palpi are of 
average length, the thumb not so long 
as » la\\ ; on its tip are three lingers, the 
median one (seen Prom the side) plainly 
larger than the others. The mandibular 
plate is rather broad, its sides concave 
near the tip. and almost truncate, some- 
times apparently broadly, though not 
deeply, emarginate; tin- median notch i 
air quite slender, femur I more than twice as long as broad; tibia I 
plainly longer than patella I; tarsus quite long, ending in a claw, which 
is stronfflv bent near its middle and four-cleft beyond. 
Fig, 14. — Tetranychus desertorum: 
palpus and mandibular plate— 
enlarged (original). 
Fig. 15. — Tetranychwi gloveri: palpus and 
mandibular plate — enlarged (origi- 
nal). 
scarce 
lv visible. The legs 
