1881.] Entomology. 817 
with earth kept well moistened, closely resembles that of JZ. 
piceus of Europe, so that the figure of that species here given (Fig: 
I, ¢) will very well illustrate its appearance. The anal appendages 
are much longer in our species, very stout and parallel in their 
basal third, thence suddenly narrowed and slightly divergent. 
They are annulated and their length seems to vary according to 
the specimens. In the middle of the anal joint there is ventrally a 
triangular tubercle, and on the apical margin of the penultimate 
joint are two more prominent, connected, cone-like protuberances. 
The anal joint dorsally terminates in two stout, short tubercles, 
each bearing a spine. The pupa is chiefly characterized by the 
sternal process or spine, and by having on each abdominal joint 
behind each spiracle, a filamentous, curved, tapering process, 
minutely annulate and with a seta issuing from tip. n eac 
side of the anterior border of the prothorax is a set of three of 
these processes largely developed. Their function has not been 
critically studied, but they undoubtedly act as secondary trach- 
aley. , 
Tue CuLtivation oF PyRETHRUM AND MANUFACTURE OF THE 
PowpDErR1—2., Application of Pyrethrum in Fumes.—The powder 
burns freely giving off considerable smoke and an odor which is 
Not unpleasant. It will burn more slowly when made into cones 
by wetting and molding. In aclosed room the fumes from a small 
quantity will soon kill or render inactive ordinary flies and mos- 
quitoes, and will be found a most convenient protection against 
these last where no bars are available. A series of experiments 
made under our direction, indicates that the fumes affect all in- 
Sects, but most quickly those of soft and delicate structure. 
This method is impracticable on a large scale in the field, but 
will be found very effective against insects infesting furs, feathers, 
herbaria, books, etc. Such can easily be got rid of by enclosing 
the infested objects in a tight box or case and then fumigating 
them. This method will also prove useful in greenhouses, and, 
with suitable instruments we see no reason why it should not be 
applied to underground pests that attack the roots of plants. 
3. Alcoholic Extract of Pyrethrum powder—The extract is easily 
obtained by taking a flask fitted with a cork and a long and ver- 
tical glass tube. Into this flask the alcohol and Pyrethrum are 
troduced and heated over a steam tank or other apparatus. 
The destillate, condensing in the vertical tube, runs back, and, at 
the end of an hour or two the alcohol may be drained off and the 
extract is ready for use. Another method of obtaining the ex- 
tract is by repercolation after the manner prescribed in the Amer- 
ican Pharmacopceia. The former method seems to more thoroughly 
€xtract the oil than the latter; at least we found that the residuum 
of a quantity of Pyrethrum from which the extract was obtained 
»Y repercolation had not lost a great deal of its power. The first 
* Concluded from September number. 
