IOWA ACADEMY OP SCIENCES. 
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short, squarish, light colored, margined with black. The ter- 
minal joint is cone-shaped, tip and sides black, but central basal 
portion light colored. The ventral color of the abdomen is 
whitish, and the posterior margin of each segment indicated by 
two fine, short, black lines. 
This species was first noticed about the latter part of August 
in the summer of 1894. It lives on the common dock, Rumex 
altissimus. It is most commonly found on the tips of the 
branches in autumn and causes them and their leaves to curl up 
into a rather compact ball. In a short time these take on a 
brown color and some of them soon die, only the stems remain- 
ing alive. These gnarled bunches are very characteristic and 
can be recognized as far as visible. They very much resemble 
the work of plant lice and very likely have been considered by 
some as such. 
One important fact in its life history is the production of 
honey dew in connection with the white waxy secretion. 
It was first studied as a new species and a description written 
for it under the name Aphalara rumicis. But since then care- 
ful comparison with the description of Aphalara exilis given by 
Flor in ‘'Rhynchoten Livlands,” Vol. II, p. 532, shows that the 
two forms are very nearly related, possibly the same species, 
the variations due probably to locality and host- plant. Yet the 
fact of such a difference in host-plant, when considered in con- 
nection with observations on other species in regard to this 
point, indicates that there is an essential difference. The dif- 
ference in color-markings could be easily reconciled because 
they have been found quite variable in some species. The first 
tarsal joint in Aphalara exilis is stated to be as long as the sec- 
ond, and they together about half as long as their tibia. In the 
form at hand the first tarsal joint is about half as long as the 
second, and they together about one- third as long as their tibia. 
The ovipositor of the female of the present form is very similar 
to that of A. polygoni, but in the male genital organs the claspers 
and the horizontal backwardly projecting portions of the dorsal 
plate seem to be quite different, while in A. exilis they are given 
as almost identical, there being only a slight variation in the 
claspers. The form on Rumex acetosella has not been found 
here as yet, and until a careful comparative study of the life 
history of the two forms is recorded it is difficult to say just 
how the form on Rumex altissimus should be designated. At 
present it is thought best to consider it as a variety of Aphalara 
exilis. 
