105 



The minute hymenopterous parasite described by Miss Emily A. 

 Smith under the name of Coccophagus leecuiii* was not infrequent. 

 Numerous specimens emerged in our breeding cages early in Octo- 

 ber, at which time also the adult Hyperaspis appeared abundantly. 

 Only an insignificant percentage of the brood was actually parasit- 

 ized, however, and the number of these parasites occurring was far 

 below those of the year 1880, at which time the last previous up- 

 rising of this species culminated. There is consequently every 

 probability that the maple bark louse will be certainly not less 

 abundant next year than this, but probably far more ao, and that 

 the year following will be marked by their almost total disappearance. 



An interesting observation of my first assistant, Mr. H. Garman, 

 is here inserted from his notes dated July t24. 



"A nest of the goldfinch, CJirysomitrls tristis, was found to-day in 

 an osage orange hedge, and on examination proved to be covered 

 outside with the silken nests and bodies of the female of Pulvi- 

 naria innnmerahilis. These had been collected some distance away, 

 as there were no maple trees in the neighborhood. There were no 

 bark lice on the leaves of the hedge at a distance from the nest, 

 but in the neighborhood of the latter the leaves were covered with 

 them, some still active. The fact illustrates a means of dispersal 

 for this bark louse which does not seem to have l>een noted by 

 writers." 



Experiments. 



For the purpose of testing precisely the value of various local 

 applications to trees infested by the maple bark louse, 1 instituted 

 a series of experiments with all the substances likely to be of 

 economic use, and the results are herewith given. 



Kerosene Emulsion. 



On the 18tli July, when the leaves of th3 trees were generally in- 

 fested by the young, we began experiments with the kerosene emul- 

 sion, usnig a strong soap suds for the preparation of the emulsion, 

 and diluting with water to give two and a half per cent, of kero- 

 sene. 



Experiment 1. — ^At three p. m., a single leaf bearing many young 

 lice was dipped in this fluid for a moment, and two hours later a 

 number of the insects were taken from the leaf and examined with 

 a microscope. All were evidently dead, and those on the leaf also 



*American Naturalist, Vol. XII, p. 6G1. J. Duncan Putnam in his admirable article on 

 Pahnairia i.nnnmerabiUs published in Volume II of the Proceedings of the Davenport 

 Academy of Sciences remarks, in a foot note to page 33-2, concerning this species: "I 

 am v^.ry much inclined to think that Platyjasfer /flca/ii/; described by Fiteh in his 5th 

 New York Report, as infesting Lecanlum guprcitronis may prove to be really a Coccoph- 

 agus nearly allied if not identical with this species. Tlie description applies too well, to 

 easily believe that the two species belong to different families. In this event Dr. Fitch's 

 reference to the Proctotrupidpe is of course wrong." 



I am not able, however, to agree with Mr. Putnam in this matter, as the description by 

 Fitch to which he refers states that the antenna of his species are threadlike, with the 

 joints slender, three times as long as thick, the last one not enlarged; whereas, in the 

 specimens of Ooccoi)hagus lecanli bred by us from Pulviaaria, the antennte are somewhat 

 clavate, the joints less tiian twice as long as thick, and the last one is decidedly enlarged. 



