398 
The Ohio Naturalist. 
[Vol. Ill, No. 3 , 
by its resemblance to the fruit stems and also by the sticky nature 
of the fruit. 
M. humilis Stal. — This species seems to be strictly confined to 
the rayless golden rod ( Bigelovia douglasii group) ' The female is 
of a pale green color, similar to that of the new growth upon 
which it stays. The male has a shining black stripe down the 
back and depends upon its agility in dodging around the stems 
for protection. The adults appear in July, the males having 
mostly disappeared by August ist. It is a common species in 
southwestern Colorado and occurs sparingly well up in the 
mountains west of Fort Collins, Colo., but has never been taken 
in the foot hills or on the plains, although the Bigelovia abounds 
there. 
. 1 /. robusta Uhl. — This small pale green form is found abund- 
antly on the bushy Atriplex (A. canescens) throughout the south- 
ern half of Colorado and down into Arizona. The plant appears 
almost white, but the young shoots and stems where the insects 
rest are pale green. 
. 1 /. bisignata Ball.- — This pretty brown-marked species occurs 
on Gutierrezia euthamiae, a little yellow'- flowered Compositae that 
grows in small clumps all over the plain region of Colorado and 
well up into the mountains. There appears to be two broods of 
this species, one appearing late in May and another in September. 
The difference in altitude affects the time of appearance so much 
that it is hard to determine the number of broods except where 
the same locality is under observation during the entire year. 
GENUS PKDIOPSIS. 
The food plants of a number of our species have already been 
definitely recorded and a few more are added here. The willow 
forms, as far as studied, seem to be as strictly confined to one 
species or group of willows as are the willow-inhabiting forms of 
Idiocerus. 
P. tristis Van D., and trwiacidata Fitch. — were both injuri- 
ously abundant on cultivated plums at Fort Collins, Colo , in 
1902. The adults of the latter species appeared the first -week in 
July and those of tristis a week or more later. 
P. suturalis O. and B. — seems to be strictly confined to the 
black willows (Salix amygdaloid.es and nigra), where it is fairly 
common locally. 
P. erythrocephala G. and B. — An abundant species on the 
narrow-leaved willow ( S . longifolia). By an oversight the habitat 
of this species was omitted in Osb. and Ball’s review of this genus. 
It is known from Iowa, Nebraska, Kansas and Colorado. 
P. U ivialis Ball. — This species occurs abundantly on the black 
willows (S. amygda/oidcs) in Colorado. The adults appear by 
the first of July. 
