CT> 



A FORTNIGHTLY REVIEW 



OF THE 



LUMt 

 BdTAI 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. qak 



Vol X. No. 245. 



BARBADOS, SEPTEMBER Ifi, 1911. 



Pkick Irf. 



CONTENTS. 



Book Shelf ... . • ... 



British Iiiiiieii:ilCouiicil of 

 Coiuiiiei'ce 



Calcium Cyaniiiiiide, Im- 

 poitance as a Manure 



Calotro] lis, Fil >re of 



Canary Islands, Trade and 

 Couiuierce of, 1010 ... 



Castilloa Plants, Constitu- 

 tion of 



Castor Oil Seed f lom 



Uganda 



Cotton Notes : — 



Trials nf Cotton Varie- 

 ties in Indi.a 



West Indian Cotton ... 



Date Palm . ^ 



Department Kews 



Fungus Notes : — 



Recent Work on Bor- 

 deaux Mixture 



Gleanings 



Hawaii, Forestry in 

 Influence of Leaves on 

 Development of Fruit 



Insect Notes : — 



An Insect New to the 

 West Indies ., 



Page. Page. 



. 295 Limes from .St. Lucia, Re- 

 port on 292 



296 ; Maniliot Glaziovii Latex, 

 I Extraction of .%l 



297 Market Reports 30t 



303 j Notes and Comments ... 290 



I Paper-Making, Materials 



299 ! for 299 



rinnts. Health of, as Re- 

 293 lated to Insects ... 289 



Registration and Impurla- 

 303 tion of Stock in St. 



Vincent 303 



St. Kitts and the Canadian 



National Exhibition 297 

 St. Kitts.Trials with Green 



Dressings 293 



St. Lucia Schi lols, Agricul- 

 1 tnre and Hygiene in 29" 



[Students' Corner 301 



Sugar from .Shredded Cane 303 

 Sugar Industry : — 



Sugar-cane Seed, Com- 

 position of 291 



j Molasses and Milk Pro- 



I duction 291 



.Tonkin Rul.iier tree ... 299 



i Trade and Auriculture of 



1 . St. Vincent, 1910 ... 297 



294 

 294 

 292 

 291 



302 

 300 

 298 



29G 



. 298 



The Health of Plants as Related 

 to Insects. 



X a short article, which appeared in the 

 Journal of Economic Entomology, for 

 >pril 1911 (see Vol. 4, p. 2()9), Mr. J. B. S. 

 yO Norton, of the Maryland State Aoricultiiral Experiment 

 •^ Station, discusses the topic indicated by the heading 

 2j appearing above. 



Mr. Norton finds examples for the illustration of 



his points in certain well-known conditions with 

 . . . . I I I 



reference to insect pests in the United States. A per- 

 usal of this article has suggested the desirability of 

 a discussion of the subject along similar lines, using 

 as examples insects which are known to rcadei-s of the 

 Agricultural Newi^. 



In considering the relation of insects to plantjJ, 

 the author places the health of the plant as the basis 

 of argument. In ordinary practical work, this feature 

 although important is largely lost sight of in dealing 

 with the question of profit and loss. Insects injure 

 plants, and as a result the crop is snmller or of an 

 inferior quality, and consequc'ntly profits are reduced, 

 or in extreme cases the crop is ruined and becomes 

 a total loss. It may thus be of interest to note the 

 ways in which insects affect the health of plants, but it 

 must be borne in mind that everything influencing 

 the plant adversely has also an unfavourable effect 

 on the net results to the planter or farmer. 



The effect of insects on the health of phjnts may 

 be of two kinds, direct and indirect. Direct injury 

 results when the insect actually removes portions of 

 the plant which are essential to growth and reproduc- 

 tion, or when the actual food material of the plant is 

 removed, or when the action of the insect interferes with 

 the physiological functions of the several parts. Indirect 

 injury takes place when disease-producing organ- 

 isms are either actually conveyed from plant to plant, 

 or are provided with easy means of entering into the 

 tissues of the plant. 



Direct injury to plants is of f^reat importance 

 and often very obvious. The feeiing of myriads of 

 cotton worms in afield of cotton destroys large numbei^l 



