58 TRINIDAD AND TOBAGO BULLETIN. iXIX. 2. 



Lizards are an important enemy of the froghopper in uncultivated 



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



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



but agricultural processes, particularly burning the trash, destroy many 



lizards. 



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

 [ in reducing the number of frogs and toads in the cane districts. 



Two predaceous grasshoppers, Xipliidium and Pflugis, destroj' small 

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

 abandoned land than among the canes. 



Four species of ants have been found killing froghoppers in Trinidad 

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

 liarm than good by carrying ofi froghoppers that are infected with green 

 luuscardine. 



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

 as the candle-tiy or lire-Hy {Lanqiyridce) was reported eating an adult 

 froghojiper. 



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

 in Trinidad and other countries. The Mexican 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. 



Spiders, particularly the jumping spiders or Attidce, destroy many 

 adult froghoppers. 



The green nmscardine 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. 



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 sterilised rice or similar 

 media. The spores so obtained are mixed with rice flour and spread on 

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

 light traps. The success or failure 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 further investigation. 



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 nmscardine and has 

 never been recorded before October. It can only be cultivated with 

 difficulty and does not lend itself to artificial distribution. On occasion 

 it has destroyed large numbers of froghoppers and infected specimens 

 are killed more rapidly than by the green nmscardine. 



Hyper-parasites. Under this heading are included the animals 

 which destroy the enemies of the froghojiper and so allow it to increase. 



