SUMMARY. 1.'j5 



Another parasite of the nymph is the Mermis worm, a Nematode 

 which is occasionally found coiled up in the abdomen of the nymph or 

 adult froghopper. It is not common and nothing is known of its 

 life history or habits, (p. 70). 



The Green Muscardine fungus is only rarely found on the nymphs in 

 the field (p. 70). 



The adult froghopper has a long list of parasites and enemies. 

 Seventeen different birds have been proved to eat adult froghoppers (see 

 Table IV p. 71). One of the most important of these is the Scissors- 

 tail Fly-Catcher which migrates to Trinidad from the mainland of South 

 America at the beginning of each wet season, arriving in May or June 

 and leaving' in October and November, (p. 70). 



Lixards are an important enemy of the froghopper in uncultivated 

 land but in the cane fields they are generally scarce, perhaps more so in 

 Trinidad than elsewhere. This has been said to be due to the mongoose, 

 but agricultural processes, particularly burning the trash, destroy many 

 hzai'ds. (p. 78). 



Cultivation, and possibly also the mongoose, have had a similar effect 

 in reducing the number of frogs and toads in the cane districts (p. 79). 



Two predaceous grasshoppers, Xipliidium and Pflugis, destroy small 

 numbers of froghoppers, but both are commoner in the traces and 

 abandoned land than among the canes, (p. 79). 



Four species of ants have been found killing froghoppers in Trinidad 

 and others are known in other countries. Ants sometimes do more 

 harm than good by carrying off froghoppers that are infected with green 

 muscardine. (p. 80). 



On one occasion an adult of the small luminous beetle, known locally 

 as the candle-fly or fire-fly {LavipyridcB) was reported eating an adult 

 froghopper, (p. 80). 



Several Soldier-Bugs {ReduviidcB) are known to destroy froghoppers 

 in Trinidad and other countries. The Mexicfin Bug was one of these ; it 

 was introduced by Urich but failed to establish itself. Owing to their 

 varied food it is difficult to estimate the relative harm and good done by 

 these insects (p. 81). 



Spiders, particularly the jumping spiders or Attidce, destroy many 

 adult froghoppers (p. 82). 



The green muscardine fungus is probably the most important natural 

 agent in the control of the adult froghopper. Under favourable conditions 

 the greater part of a brood may be killed by it. It is, however, rarely 

 common on the first brood and with the later broods its prevalence 

 depends on weather conditions (p. 82), 



Attempts to infect fields artificially have been made but so far the 

 results have not been conclusive. The fungus can, with precautions 

 be readily produced in quantity by growing on sterihsed rice or similar 

 media. The spores so obtained are mixed with rice flour and s)3read on 

 the fields by blowers, or the adults are attracted into the mixture by 

 light traps. The success or faiku-e of the individual experiment 

 depends entirely on atmospheric conditions. In unfavourable weather 

 even the natural infection dies out, while when conditions are suitable 

 for its spread there is usually sufficient natural fungus present to start 

 an epidemic. The cost of such treatment is however comparatively 

 small and on most estates would be repaid by the saving of a few acres 

 of cane. The method is worthy of furtlier investigation (p. 84). 



The Empusa fungus kills the adult froghoppers and fastens them to 

 the leaf of the cane in exposed situations usually some distance from the 

 base of the leaf. It is much rarer than the green muscardine and has 



