ECONOMIC ZOOLOGY ENTOMOLOGY. 255 



is tLo most iiiiportiUit enemy of the western jiinc in cei-tMin \)i\v\s of Idaho 

 where the destruction of this tree was invest iiiatcd. 



The presence of the pest is indicated by dead and dying trees and by pitch 

 tubes and small quantities of resin in tlie ere^•i(•es of the l)arlv. Tlie insect Is 

 lound throuf,'hout Idalio and from Calirornia to Washington and attacks the 

 western yellow pine and su.^'ar pine. It is estiniat(>d that from 2 to 5 per cent ef 

 pine timl)er has been destroytMl annually by this iK'st during tlie past -i years. 



A brief account is given of the obsei'vations made by a number of investi- 

 gators in Idaho, Waslnngton, and elsewhere. The life history and habits of the 

 insect are traced in some detail and brief notes are given on the natural 

 enemies. The pest ajtpears to attack and destroy the best specimens of trees 

 and is capable of devastating pine trees over large areas. The insect passes the 

 wintei- in the outer bark of trees which were killed during the previous summer. 

 On this account it is recommended that infested trees be located in the fall 

 and cut between October and May, after which the bark should be removed and 

 destroyed. 



Insect enemies of forest reproduction, A D. Hopkins ( U. 8. Dept. Agr. 

 Year hook I'JOo. pp. 2'i!)-2'iG, p(jx. !)). — Insect injuries to foi'est trees may occur 

 during the period of flowering, fruiting, germinating, or growth of the seedling, 

 sapling, and matun^ trees. Brief accounts are presented of some of the more 

 noted forest insects and of their attacks upon sprout forests. While ordinary 

 insecticide methods are of some value in the control of forest insects, the chief 

 reliance must be placed on systems of forestry. 



Two insect pests of the elm, A. L. Melander (Wasliingtoii ,Stu. Bill. 7.'/, 

 pp. 7, fig. 1). — Elm trees in Washington are sometimes greatly injured by the 

 eim bark-louse. This pest may be controlled by thorough spraying with the 

 lime-sul])hur wash during February or March. 



The elm leaf-louse is also quite a serious pest, but may be largely controlled 

 liy a winter spray of lime and sulphur, or, if this is not given, the iise of kerosene 

 emulsion will yield the desired results. Formulas are given for preparing these 

 insecticides. 



The mosquito, T. B. Symons, T. H. Coffin, and A. B. Gahan {ManjJand Sta. 

 Bui. Ui'.i. pp. ll-12.'i, figs 37). — The agency of mosquitoes in transmitting dis- 

 eases to man is briefly discussed and descriptions are presented of mosquitoes 

 connnonly observed in Maryland. Considerable interest has recently been 

 aroused in mosquito extermination, particularly in the neighborhood of Balti- 

 more, where favorai)le conditions prevail for the multiplication of these pests. 



The usual line of treatment is discussed, including drainage and the use of oil 

 a.nd other insecticides. Brief mention is made of some of the less common 

 substances used in destroying mosquito larva*, including a number of proprie- 

 tary remedies. The value of lime, copper sulphate. carl)()lic acid, creosote, and 

 oil is also discust. 



Mosquito control, II. J. Quayle {California Sta. Bill. 17S, pp. ')■'>, figs. 35).-=- 

 At the recpu'st of the Burlingame Improvement Club the station undertook 

 an examination of a tract of land near San Francisco badly infested with 

 mosquitoes. The species most numerous in this region was Ochlcrofatiis lati- 

 rittatus, but the malaria mosquito and other .epecies were also present. A 

 general account is ]ir(>sent(Ml of tb(> life history and nugration of mosquitoes 

 and of their cdnnei-lion with disease in man. 



The campaign of eradication undertaken by the station consisted in the 

 establishment of a thorough system of drainage in the salt marshes where the 

 mosquitoes chiefly prevailed and in the use of oil on a few of the pools in 

 fresh-water creeks. In a few instances similar work was carried out by pri- 

 vate individuals to rid their own property of mosquitoes. The success of the 



