ENTOMOLOGY. 1065 



sisting of a mixture of apple, cherry, peach, pear, pUirn, chestnut, and wahuit. 

 Apple trees which were treated at the rate of from 15 to 25 gm. cyanid of potash per 

 100 cubic feet, on different days from Marcli 2:> to April 13, received no injury. 

 Peach treas wliich were fumigated at the rate of 15 gm. per 100 cubic feet were not 

 injured, while a number of trees exposed to the gas generated from 20 gm. per 100 

 cubic feet were slightly injured and the grass around the base of the trees was killed. 

 The experiments demonstrated that it is unsafe to allow peach trees to be exposi-d 

 to the action of hydroc!yanic-acid gas for a period of 12 hours, whatever weight of 

 cyanid of potash i>er culjic foot was used. Vigorous trees, including peach, may be 

 treated witii 2.1 oz. of cyanid per 100 cubic feet for not more than .'50 mimites, while 

 the trees are dormant. Peach trees wliich are not vigorous may be injured l)y such 

 treatment, but the injury is not usually i)ermanent. Peach trees in theorchard may 

 be treated from 30 to 60 minutes with 1:J oz. cyanid per cubic foot, even after the 

 buds begui to open. AValnut, chestnut, plums, and cherries will endure the same 

 treatment as peach. 



With regard to the effect of the gas on scale insects the experiments showed that 

 fumigation may be depended upon to exterminate the San Jose scale on orchard trees 

 of medium size. Experiments were made to determine the best proportions in whicth 

 to mix the cyanid, sulphuric acid, and water. It was found that a slight exi'ess of 

 acid and from 2 to 4 times the usual quantity of water gave rapid and unifoi-m acti(jn 

 and satisfactory results. The smaller the pieces of cyanid the more rapid is the 

 chemical action, and where the cyanid is l)roken top finely the chemicals may be 

 thrown out of tlie vessel in which they are contained by the violence of the 

 reaction. 



It was found that in fumigating trees when the earth was moist about 50 per cent 

 of the gas was absorbed by the soil. It is recommended that double the amoimt of 

 cyanid generally used for nursery stock should be used in orchard work. 



The author gives a detailed description in connection with drawings and figures 

 of a hexagonal box fumigator designed for use in orchards. The chief advantages 

 of this fumigator are that it allows a rapid and accurate estimate of the cubic con- 

 tents, it may be placed around a tree without being elevated over it, it contains a 

 minimum amount of waste space, it can be stored in a comparatively small space, and 

 it does not break off or rub the buds. The cost of fumigation varies so exceedingly, 

 according to the style of fumigator used and other conditions, that it can not be stated 

 except with qualifications. When 1 oz. of cyanid is used for every 100 cubic feet of 

 space the cost is about 12i cts. jier tree when fumigated with tents, and 18 cts. when 

 treated with a box fumigator. 



The Aphididae of North America, W. I). Hunter ( Iowa SUi. Bui. 60, pp. 01- 

 138). — In this Inilletin the author has compiled a list of titles of the literature on 

 North American plant lice. A list of titles of general articles is given, followetl by 

 a catalogue of the family Aphididje, arranged in a systematized manner with refer- 

 ence to literature under each species. A host index of the Nortli .\merican species 

 of Aphidid;e is also presented, and the l)ulletin is furnished with an index to the 

 species of jilant lice which are discussed. The total number of genera recognized in 

 the bulletin is 32, and of species 325. 



Familiar butterflies and moths, AV. F. Kirbv {Loiuhm, Paris, Ncir York, and 

 Melbonnw: CaMill S- Cn., Limifcd, /HOI, pp. 144, pis. 18,JigH.4). — In tliis volume the 

 author gives a general (U-scription of the appearance, life history, and habits of a 

 number of conunon lepidoptera, including vari(jus families of butti-rllii's and moths. 

 Brief dii'ections are giwn for the collection of butterfiies and moths, together witii 

 notes on the occurrence of these insects in different seasons of tlu' year. \ mnui)er 

 of species considered are of economic importance, and their food plants arc men- 

 tioned. The plates illustrating the work are in color an<l well executed. 



The codling moth and late spraying in Oregon, \. I'. Cointi.KV {Onynii Sla. 

 Hal. i::>, pp. in-lOi), ph. 4.) — Tilt' author gives an account of a trip tliioiiy;!) certain 



