Ix. 



TEXT FIGXJRyiS.-GontmHed. 



Fig. 8 Diagram to illustrate the activity of adult froghoppers tluring tiie 

 night. 



The four nj^mph stages of the froghopper. 



The Syrphid-fly ; pupa. 



The Syrphid-fly ;. adult. 



The Trinidad Boat-tail {'jaisqiialas liujnhru.) 



The Washer-woman (Fluvicola pica.) 



The White-headed Widow (Anmdinifola JpAicocephala.) 



The Scissors-tail Fl^'-catoher (Mi/vulus tyrannns.) 



The Tick-bird {Crolophaga ani.) 



A predaoeous (rrasshopper {Xiphidium saltator.) 



The Mexican Bug {Cantnhis plagiaticollis), (From F. W. Uricli). 



Diagram illustrating the Parasite Complex centring round the 

 froghopper. 



Fig. 20 Annual rainfall on six Trinidad sugar estates 1907 to 1918 with 

 the total crop for the corresponding period. Note the absence of 

 relation between the two. 



Fig. 21 Monthly rainfall on a Trinidad sugar estate during five years 

 remarkably free from blight. Note regularity of rainfall as 

 compared with Fig. 22. 



Fig. 22 Monthly rainfall on the same estate during six yeai's of wide- 

 spread blight. Note the marked drop in all cases in September 

 or October at the "Indian Summer" (e.p. lig. 21.) 



Fig. 23 Monthly rainfall during 1918-1919 on three estates where no 

 damage was reported (c.p. fig. 24.) 



Fig. 24 Monthly rainfall during the same period on four estates when the 

 damage was more or less severe. Note again the more severe 

 "Indian Summer" drought in September, (c.p. fig. 23.) 



Fig. 25 Diagram sho^ving the relation between the commencement of the 

 wet season and the dates of the principal broods of froghoppers 

 from 1906-1919. 



Fig. 26 Map of Sugar districts of Trinidad showing approximate 

 boundaries of the different soil types (After Wall and Sawkins). 



Map of Cedar Hill Estate showing the distribution of l>light in 

 1900, 1912 and 1919 in relation to soil. 



Diagram of \aluable chemical constituents in soil of ten fields 



arranged from left to right in approximate order of liabilitv ti> 



blight. 



Diagram of St)., percentage in the soil of the same fields. 



General types of succession of the three chief froghopper broods 

 in different localities or in different years. 



Fig. 31 Diagram to explain liability of varioiis fields to blight in different 

 years. For explanation see text. 



Fig. 32 Simple form of light trap for attracting adult froghoppers, 



