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TRINIDAD AND TOBAGO BULLETIN. [XVIIL 2. 



PLANT DISEASES AND PESTS, 



CONTROL OF THE CACAO THRIPS IN TRINIDAD 



AND TOBAGO. 



By F. W. Ukich, 

 Entomologist, Board of Agriculture. 



{With 16 Figures). 

 The following popular account of the Cacao thrips {Selenothrips 

 ruhrocinctus) and methods of controlling it are intended principally for 

 the use of the small proprietors and drivers on estates : — 



WHAT AKE THRIPS? 

 Thrips are very small insects which belong to the order called 

 Thysanoptera. When young they have no wings but crawl around on 

 the plants on which they live. Tiiey have a habit of carrying their 

 excrement in a small drop at tlie end of their bodies. In the full grown 

 stage they have wings and can tly from tree to tree and even farther 

 especially when helped by the wind. In the adult and young stages 

 tlu'ips live by sucking the sap from the leaves of their food plants. 



rig. 1. 



Fig. 1.— Adult female thrips, drawing by Mr. C. IJ. Williams. Greatly enlarged with her wings e.xpandec 

 The natural size it about 1-24 of an inch in length of body, ('olour jet black. 



