THE AMERICAN ENTOMOLOGIST. 



45 



mend, therefore, the alcoholic extract of 

 Pyrethrum, diluted at the rate of i part of 

 the extract to 40 parts of water, and 

 sprayed upon the plants, as an effectual 

 remedy against the worm. 



The extract is easily obtained by taking 

 a flask fitted with a cork and a long and 

 vertical glass tube. Into this flask the 

 alcohol and Pyrethrum is introduced and 

 lieated over a steam tank or other moderate 

 heat. The distillate, 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. 



Let us now briefly consider the approxi- 

 mate cost of using this material at present 

 figures. The powder is now selling in 

 California at wholesale, in 8-lb. packages, 

 at $1.25 per lb. ; but from facts kindly 

 communicated by Mr. Milco, it appears 

 that he has raised as much as 647 lbs. to 

 the acre, and that the cost of production, 

 milling, etc., on a large scale, need not ex- 

 ceed 6 to 7 cents per lb., because in the 

 experiments attending the introduction of- 

 the plant many obstacles and expenses in- 

 cident to new enterprises have had to be 

 met. The plant is wonderfully free from 

 insect enemies and blooms all through 

 the summer, and there seems no good 

 reason why it should not grow in most of 

 the Southern States. 



Carefully estimating from the results of 

 experiments made, it will require about 

 one and three-quarter pounds of the Pyre- 

 thrum powder to go over an acre of cotton 

 at medium height ; in other words, that 

 quantity of Pyrethrum to 20 lbs. of flour or 

 other diluents will answer the purpose. 

 Such b^ing the case, the question as to 

 whether the Pyrethrum can be used as a 

 substitute for Paris green, London purple, 

 and other arsenical powders resolves itself 

 in one of relative market price, and if Mr. 

 Milco's estimates are warranted-^and no 

 one in the country is better able to state 

 the facts or give the figures on the subject — 

 the Pyrethrum may be produced as cheaply 

 as even London purple. It is a question 

 which future experience alone can deter- 

 mine, but that the prospects are encourag- 



ing there can be no question, and it is 

 highly probable that the planter in the fu- 

 ture will make it a rule to grow a patch or 

 a few rows of this most useful plant as a 

 ready means wherewith to protect his crop 

 from the worm whenever the occasion for 

 so doing presents itself. 



So far as experiments have been made 

 there would seem to be a decided advan- 

 tage in point of economy in tl]e use of the 

 crude powder, since, in the ordinary meth- 

 ods of spraying, 40 gallons of liquid are 

 required for an acre, and to produce this 

 amount of diluted extract of Pyrethrum at 

 the above figures would require about six 

 pounds of powder. This diluted extract 

 has the advantage, however, over every 

 other liquid so far used that it contains no 

 solid and obstructing particles. It may, 

 therefore, doubtless be used in a much finer 

 spray than any of the other poisons. 



^ ^ 



Intelligence in Ants. — Whilst weed- 

 ing in the garden last August, I broke open 

 the upper galleries of a nest of small black 

 ants, and in so doing scattered a number 

 of eggs, which had been carried up from 

 below, that they might be warmed by the 

 sun, which at the time was shining brightly. 

 As I watched the ants gathering them into 

 the nest, I noticed a little fellow" dragging 

 one, two or three times larger than himself, 

 up what must have seemed to him a very 

 steep hill ; at last he stuck fast, and, after 

 a few plucky efforts, he left the egg, made 

 a few casts round the ground to see how the 

 " land lay," and then returned to the egg, 

 which he pulled up an easy ascent, of which 

 he had been in search, and which was in 

 quite another direction to the one in which 

 he was going when he stuck fast. — Thomas 



Winder, Sheffield, in Science Gossip. 



■* — ♦ 



The Beheading of Flies by a West- 

 ern Plant. — Professor Gray requests 

 those who have an opportunity of obtain- 

 ing the plants Mentzelia ornata and M. 

 nuda, both of which occur in our western 

 plains and prairies, to investigate whether 

 this cruel behavior to flies is well founded. 

 It is declared by a French naturalist, who 

 has studied it in Paris, that the stiff 



