86 FROGHOPPER BLIGHT OF SUGAR-CANE 



The Empusa Fungus. 



This fungus, a species of a well known group of insect parasites, is 

 very much scarcer in the fields of Trinidad than is the green 

 muscardine. 



The insect, when attacked by it, usually remains attached to the leaf 

 blade high 'ip on the upper or under side well away from the base of 

 the leaf. This would indicate that the death of the insect occurred at 

 night time when it was out sucking and that it was more sudden and less 

 preceded by lethargy than when caused by the green muscardine. The 

 insect when dead is also in a more natural position than with the latter 

 fungus and the hind legs are not stretched out behind. 



The appearance of the fungus shortly after the death of the frog- 

 hopper is a soft moist jelly-like mass of fungus mycelium between the 

 body of the insect and the leaf. At this stage the spores are shot off 

 and then the fungus dries up leaving the dead adult attached to the leaf 

 by a brown net-like palisade of dried hyphse. 



Nowell examined the fungus in its. moist stage and found the 

 characteristic sj^ores of Emjiusa and also a number of minute motile 

 bodies probably Protozoa. 



The first reference to the fungus is by Urich (1913 C. p. 27) who says 

 " it was active last year I^191'2j and in several districts quite a large 

 number of adult froghoppers were killed by it. It was particularly 

 prevalent in the Princes Town and Naparima districts." 



Mr. E. E. Fabien, Manager of Cedar Hill Estate says that in October 

 1912 a large number of the froghoppers on that estate were destroyed by 

 it, and .J. McPherson. Manager of Ben Lomond Estate, wrote at the end 

 of 1912 in an unpublished circular "since the beginning of November 

 1912, while we were getting showers of rain daily, a natural fungus was 

 very prevalent and destroyed large numbers of froghoppers. When the 

 fungus attacks them, they leave the heart of the cane and walk up into 

 the sun at the top of the leaves where they remain until they die." 



Since 1916 I have found it in the cane fields on various occasions 

 which are as follows : — 



Date. 

 9. X. 16 



25. X. 17 



26. X. 17 

 16. XL 17 

 22. XL 17 



1. IL 18 



19. XL 18 

 31. XII. 18 



6. I. 19 



20. L 19 

 28. X. 19 



4. XL 19 



5. XL 19 

 End Nov. & beg. I 



Dec. 1920 J 



The last record refers to a very sudden epidemic which occurred on: 

 the unusually late third brood in 1920 after a wet November. Several 

 thousand dead specimens were seen on four or five different estates but 

 the greatest outbreak was at Cupar Grange. Of eighty-three specimens 

 collected at the latter locality 58 were males a.nd 25 females ; this excess 

 of males is the opposite of what is found w'ith the green muscardine 

 fungus. 



