40 



De Bussy (L. p.). Dierkundige afdeeling. [Zoological Section.] — 

 Meded. Deli ProefstaL, Medon, ix, no. 4, October 1915, pp. 112- 

 121. 



This is a portion of the Annual Report of the Station for the year 

 ended 1st July 1915. Crops grown in rotation with tobacco sufTered 

 severely from tobacco pests. The damage done by Maruca testulalis 

 and Herse (Protoparce) convolvuli has been made the subject of special 

 reports [see this Revieiv, Ser. A, iii, pp. 248, 644.] These pests were 

 relatively scarce during the past tobacco season, but whether this was 

 due to the action of parasites or of some disease is not clear. A species 

 of Acherontia was more than usually in evidence and there is reason 

 to fear that it is spreading to previously uninfested areas. The 

 Noctuid, Arcilasisa plagiata seems to have almost entirely disappeared 

 in recent years. In certain tea gardens the Limacodid, Cania hilinea, 

 was very common and did a good deal of harm. An undetermined 

 Limacodid closely related to the species of Belippa noticed in 1913, 

 attacked one or two coffee plantations. TricJiogramma pretiosu7n has 

 been bred with success with the assistance of the eggs of Mods 

 (Remigia) archesia ; another closely allied moth which frequents 

 Phaseolus mdiatus in large numbers, has also proved to be a host of 

 TricJiogramma. The trap-crops of maize near tobacco did not yield 

 so many eggs of Ckloridea (Heliothis) as was expected. One or two 

 new indigenous parasites of tobacco pests have been discovered. 



With regard to insecticides, the war in Europe has caused the planters 

 to turn to the U.S.A. for supplies, especially of arsenicals. The 

 requirement of the Java experts that Paris green and Urania green 

 should not contain more than 0'4 per cent, of arsenious acid soluble 

 in water as such [see this Review, Ser. A, iii, p. 645], is regarded by 

 the European manufacturers as unnecessarily stringent and they point 

 to the good results obtained in Russia on grain crops with much higher 

 percentages ; the U.S.A. manufacturers regarded the figures as a 

 clerical error. Izal is of little use against tobacco pests, its action 

 being much too slow ; zinc arsenite, on the other hand, as a half per 

 cent, emulsion, was very effective, had no ill effect on the young tobacco 

 plants and may be used in greater strength than Paris green if necessary. 

 The acidity of the tapioca meal used for diluting Paris green is of 

 considerable importance, as it may promote decomposition of the 

 arsenical ; it is strongly advised to use the meal as fresh as possible 

 for mixing with Paris green. Aphids have not been very troublesome 

 and it was not found necessary to free any quantity of Megilla maculafa ; 

 experiments on the native CoccinelHd, Chilomenes sexmacidata, have 

 miscarried. It has now been definitely ascertained that tobacco sent 

 to Holland after fumigation with carbon bisulphide is quite free from 

 the tobacco beetle (Lasioderma), and as the cost is small, such fumiga- 

 tion should be always carried out before export. The testing of 

 samples of fermented tobacco for the presence of Lasioderma requires 

 6-8 weeks, this being the maximum period necessary for the 

 development of the insect. Lasioderma may apparently be intro- 

 duced and travel in a number of other materials besides tobacco, 

 and the question of the control of these will require consideration. 

 Tobacco seed has been found to be infested with Lasioderma, but 

 fumigation with carbon bisulphide proved satisfactory. 



