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THE SUGAR-CANE FROGHOPPER IN GRENADA. 



By C. B. Williams, M.A., E.E.S., 

 Department of Agriculture, Trinidad, B.W.I. 



In the course of an investigation into the froghoppers (Cercopidae) of the genus 

 Tomaspis found on sugar-cane in Trinidad and the neighbouring countries, made 

 on behalf of the Government of Trinidad, I visited Grenada in December 1916 and 

 spent a few days investigating a small but severe outbreak of froghoppers in that 

 Island. The following notes seem of sufficient interest to be published without 

 farther delay. 



Grenada is the most southerly of the Windward group of the Lesser Antilles, 

 and is situated in Lat. 12° 5' N. and Long. 61° 40' W. It is about 90 miles in a 

 direct line north of Trinidad, with which island there is continuous traffic both by 

 steamer and sailing vessels. It is a mountainous volcanic island about 21 miles 

 long and little more than half as broad. 



The rainfall varies greatly in different parts of the island ; from 25 inches per 

 annum in the extreme south-west, where the country is flat, to 130 inches or over 

 in the mountains in the centre of the island. The average rainfall for twelve years 

 at one of the localities where the froghopper outbreak was most severe is given 

 below, together with the actual rainfall for 1916. 



Rainfall at Mount Hoene, Grenada. 





Jan. 



Feb. 



Mar. 



Apr. 



May 



June. 



July. 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Total 



Average 

 12 years. 



1916. 



5-0 

 5-2 



3-2 



2-8 



3-4 

 4-0 



41 

 3-7 



4-4 

 4-6 



9-1 

 5-5 



9-0 

 6-7 



9-2 

 11-7 



8-0 

 7-1 



9-8 

 6-3 



11-3 

 16-5 



7-6 

 8-3 



84-1 

 82-4 



The chief dry season is from January to May, and there is a slight " Indian summer " 

 about September. During 1916, June and July had been drier than usual — August 

 wetter, followed by a distinctly dry period in September and October ; November 

 was unusually wet. 



The sugar-cane industry of Grenada is of quite secondary importance ; no sugar 

 is exported and nearly all that is grown locally is used for the manufacture of rum, 

 and the cane-tops for stock feeding. A pest of sugar-cane in this island, although 

 bad, has nothing of the serious importance of a similar one in Trinidad, where the 

 production reaches 70,000 tons of sugar per annum. 



Froghoppers were first reported from Grenada by Uhler (Proc. Zool. Soc. London, 

 1895, p. 58) under the name of Tomaspis pictipennis, StaL Th e specimen he described 

 was captured by H. H. Smith in Grenada about 1890, 



