108 



therefore be destroyed without delay. Larvae can also be readily 

 carried in rain-wash. As this Nematode is capable of penetrating 

 through wounds deep into the husk of nearly mature nuts, those 

 dropped from diseased trees, or lying on wet soil in fields where the 

 disease is present, should not be used for seed unless the husks have 

 been thoroughly dried. 



The fact that this Nematode is dependent on a very high degree 

 of humidity for its motility and is very sensitive to desiccation indicates 

 that wide spacing, good drainage and freedom from heavy undergrowth 

 are important factors in the prevention of red-ring disease during the 

 susceptible period of growth, which is generally between the fourth 

 and tenth years. Experiments are now in progress on the value of 

 salt as a preventive of infestation and on the effects of banding trees 

 with a mixture of tar and tallow. 



Ironside (F.). Paraffin and the Carrot Fly [Psila rosae). — Gdnrs. 

 Chron., London, Ixx, no. 1819, 5th November 1921, p. 237. 



An infestation of carrots by the carrot fly, Psila rosae, was success- 

 fully checked by the application of paraffin rnixed with wood ash 

 at the rate of one quart to the bushel. As the ground was very dry 

 it was thoroughly watered with a hose, and two days later the wood 

 ash was spread thinly over the bed. The hose was again applied 

 so as to wash the paraffin down to the roots of the carrots. A few 

 days later all grubs around the roots examined were dead. For an 

 area of 25 yds. by 12 yds. two bushels of the prepared wood ash 

 were used. 



Jensen (H.). Ziekten van de Tabak in de Vorstenlanden. [Pests and 

 Diseases of Tobacco in the Vorstenlanden District, Java.] — 

 Meded. Proefst. Vorstenlandsche Tabak, Klaten, Java, xl, 1921, 

 xii -f 171 pp., 36 figs., 59 plates. Also Leiden, N.V. Boekhandel 

 en Drukkerij voorheen E. J. Brill. 



Each disease or pest of tobacco forms the subject of a separate 

 chapter of this volume. The agent concerned and the measures 

 against it are dealt with, the vernacular names and references to 

 literature being given in each case. 



The preparation and use of sprays and other means employed in 

 protecting the plants and harvested tobacco are described in the last 

 section. 



The following is a list of the insect pests concerned : Lasioderma 

 serricorne, F. ; Opatrwn {Gonocephalnin) sp. ; EiUochia lateralis. Boh. 

 {Holaniara picescens, Fairm.) ; Anomala (Etichlora) viridis, F. ; 

 Heliothis assidta, Gn. ; Prodenia litura, F. ; Phytometra (Plusia) 

 signata, F. ; Acherontia lachesis, F., and A. styx, Westw. ; Phthori- 

 maea {Gnorimoschema) heliopa. Low. ; Setoniorpha margalaestriata, 

 Keuch. ; the fire ant, Solenopsis geminata, F. ; the gramang ant, 

 Plagiolepis longipes, Jerd. ; locusts ; the mole-crickets, Gryllotalpa 

 hirsuia, Burm., and G. africana, Beauv. ; the cricket, Brachytrypes 

 achatinus, Stoll ; the bugs, Nezara viridida, L., and Gallobelicus 

 nicotianae, Kon. ; Aphids ; thrips ; and the Nematode, Heferodera 

 radicicola. Greet. 



There is also a brief section on Botys marginalis, Moore, and Agrotis 

 sp., occurring on tobacco in Deli (Sumatra) and Dj ember (Java), but 

 not yet noticed in the Vorstenlanden district. 



