286 



to, I will be greatly obliged it you will give ine the facts or reference. — [ H. G. Tryon. 

 Willoughby, Lake Comity, Ohio, December 6, 1886. 



Reply. — * * * My opinion concerning the question of Bees vs. Fruit has for a 

 long time been identical with your own, viz, that under certain conditions bees will 

 and do injure certain varieties of frnit. This opinion was arrived at, however, with- 

 out thoroughly satisfactory' experimentation upon my part, and it was with the view 

 of settling the point, so far as it was possible to settle it by experiments, that I in- 

 structed Mr. McLain to carry on the series of experiments to which you refer. Aa 

 you seem to have seen a newspaper account only, I take pleasure in sending you by 

 to-day's mail a copy of my report for 1885, which contains on pages 336 to 339 the de- 

 tails of his work in this direction. My own comments you will find in the introduc- 

 tion on page 212. I freely admit that my remarks upon his results might have been 

 more qualified and that where I state that the experiments show pretty conclusively 

 that bees do not injure fruit at first haud, I should have said "grapes" instead of 

 fruit, as the experiments were made principally with grapes. You will notice that 

 the word "conclusively" is qualified, and in reality the more I study the matter the 

 more the difficulties of settling the question by such a series of experiments are 

 forced upon me. You must admit, however, that these experiments place the burden 

 of proof upon the affirmative side as far as grapes are concerned. — [C. V. R., Dec. 

 16, 1886. 



Hydrocyanic Acid Gas Treatment for Scale Insects. 



* * * I again visited Mr. Gilraau a few days ago, and was pleased to learn that he 

 had met with very good success in fumigating his orange trees with hydrocyanic acid 

 gas passed through sulphuric acid ; we carefully examined several trees that he 

 treated with the gas when I was there a little over a month previously, and were un- 

 able to find any living Red Scales (Aspidiotus aurantii), while the fruit and foliage 

 were uninjured. Mr. Gilman says that he treats on an average four trees an hour, 

 using the one apparatus which operates two tents, and estimates that the cost will 

 amount to about 65 cents per tree, his trees being from 10 to 14 feet high by the same in 

 diameter. If it will not bo necessary to again treat these trees until after the lapse of 

 four years, this will reduce the cost of treatment to less than twenty cents a year for 

 each tree. Mr. A. Scott Chapnum, of San Gabriel, in this county, informs me that 

 some of his father's orange trees that had been treated with this gas nearly two years 

 ago are still remarkably free from the Red Scale, notwithstanding the fact that the 

 adjoining trees are thickly infested with them. The trees treated v/ith this gas, 

 however, are quite as thickly infested with the Iceryaas they were when first treated, 

 which clearly shows the great ditfei'ence in the dispersive habits of these two species. 



While at Mr. Gilman's 1 i)icked up the following insects from beneath some of the 

 trees which he had just treated with the gas : one Chilocorus bivulnerua, two Exochomus 

 pijaiel, six CoccinvlJa ahdominalls, four Psyllohora fwdata, one DiabroHca trivittata, four 

 Lar(jHS succinclus, one Euschistiis iristif/miis, two Ophioit macrKruin, six Chrysopa sp.?, 

 five Ifusca domestica, two Mydea sp.?, and one spider. The next day all had recovered 

 with the exception of one Largus, the two Ophious, one Chrysopa, the five Muscas, one 

 Mydea, and the spider. Mr. Gilman says that when he leaves the tents charged on 

 the trees all night all of the Lady Bugs on these trees will be killed. The other trees 

 are each confined in the gas twenty minutes, which includes the ten minutes re([uired 

 for generating the gas. — [D. W. Coquillett, Los Angeles, Cal., Feb. 1, 1889. 



NeTv Enemy of the Chinch Bug. 



1 notice you don'tmention, as preying on the Chinch Bug, the CasnoniapennsyJvanica 

 that I found swarming in sheaves of wheat that was infested with the Chinch, while 

 assisting with harvest in Illinois. Years later I found a Casnonia with a Chinch in 

 its mouth among a scattered colony of the latter, at the base of a leaf of green young 



