ECONOMIC ZOOLOGY- — ENTOMOLOGY. 257 



per 20 gal. of water. This uilxture uiay be ajjplied at the rate of 300 gal. per 

 acre at a cost of less than one-half that of the application of the kerosene 

 emulsion. 



Thrips on cocoa, H. A. B.\llou {Bid. Dept. Agr. Jamaica, 6 {1908), 'So. 1, 

 in). 8-11). — A brief account is given of the nature of the injury by thrips to the 

 leaves and pods of cacao. Directions are given for the preparation and applica- 

 tion of rosin wash, kerosene emulsion, and rosin and whale-oil soap compounds. 



On the structural characters of three species of Coccidae affecting cocoa, 

 rubber, and other plants in Western Africa, R. Newstead {-lour. Econ. Bio}., 

 2 {1908), No. Ji, pp. l-'i9-157, figs. 3). — The species discussed by the author 

 include Stictococcus sjo.stcdti, Pulvinaria jacksonii, and Pahcococcus theobromce, 

 the last two being described as new species. 



Notable depredations by forest insects, A. D. Hopkins ( U. S. Dept. Agr. 

 YrariooJc 1907, pp. 1. '{9-164). — A history is given of the depredations in Europe 

 and America by the defoliating and bark-boring insects. 



For Europe, the "nonne" moth {Liparis monacha), pine spinner {Dendroli- 

 tnus piiii), gipsy moth {Porthetria dispar), false caterpillars, and the eight- 

 tooth pine bark beetle (Tomicus typographtis) are mentioned and attention is 

 called to the danger of their introduction into this counry. An account follows 

 of the depredations in America by the larch worm, pine butterfly {yeophasia 

 menapia), gipsy moth, spruce-destroying beetle {Dendroctonus piceaperda), 

 Englemann spruce beetle, Black Hills beetle {D. ponderosw), western pine 

 beetle {D. hrevicornis) , destructive pine beetle {D. frontalis), hickory bark- 

 borer {Scolytus quadrispinosus), and locust borer {Cyllene roMniw). 



It is stated that nearly all gi-eut invasions by forest insects in Europe and 

 this country have been more or less of a periodical nature, which is ex- 

 plained as due to various natural causes that operate only after the gi-eatest 

 damage has been done. Most of the bark beetles can be kept under complete 

 control with little or no expense by proper adjustments in forest management 

 and lumbering operations. 



Experiments in using' various species of trees as trap trees for bark beetles, 

 W. Sedlaczek {Centbl. Gesam. Forstic, 3Jf {1908), No. 2, pp. ^J-7.i ) .— The 

 trees used in these experiments included silver fir, larch, Norway spruce, and 

 Austrian pine. Reasonably satisfactory results in attracting bark beetles were 

 obtaine<l by ringing these trees in various ways or felling them. Later the 

 trunks may be treated in such a way as to destroy the beetles. 



Insects injurious to loco weeds, F. H. Chittenden {U. S. Dept. Agr,, Bur. 

 Eitt. Bui. 6'i, pt. 5. pp. 33--'i2, figs. 7). — An account is given of the insects in- 

 strumental in reducing the abundance of stock-poisoning loco weeds in the semi- 

 arid regions of the West. The false-indigo gall-moth {Walshia amorphella), 

 which as a caterpillar feeds at the roots and crowns of locos, is apparently 

 the principal insect destroyer. Other insects mentioned as attacking loco 

 weeds, particularly Astragalus mollissimus and Aragallus lamhcrti, are the 

 loco root-maggot {Pcgomya lupini), fickle midge {Sciara inconstans), four- 

 lined loco weevil {Cleonus quadrilineatus), yellow loco fly {Tritoxa incurva), 

 spotted root fly {Euxesta notata), bur-clover aphis {Aphis medicaginis), and 

 meal snont-moth {Pyralis farinalis), as well as plant bugs, leaf hoppers, and 

 miscellaneous insects. Some of these insects are considered as highly bene- 

 ficial, since they have completely rid large areas of loco weed.s. 



The value of insect parasitism to the American farmer, F. M. Webster 

 {U. *S'. Dept. Agr. Yearbook 1907, pp. 237-256, figs. 2'/),— An account is given of 

 the gi-eat value of parasites in reducing the amount of injury due to several 

 destructive insects, notably the spring grain-aphis {Toxoptera graminum) by 



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