﻿XVI 



able. P. perforator, common in Fiji, attacking eggs of hopper 

 laid in thick stems of grass, more rarely those in cane, will prob- 

 ably gradually wander away from the cane-fields to attack the 

 eggs of native hoppers, that arc laid in stems and twigs, as it 

 now chiefly attacks the cane-hopper eggs when these are laid 

 in the stems. 



Nor must it l)e forgotten, what valuable aid these egg-para- 

 sites receive in the control of leaf-hopper from other insects 

 parasitic and predaceous, native or introduced. In fact, had 

 there existed previously no restraint to the multiplication (>f the 

 ]3est, no one who has paid the least attention to such matters 

 can doubt that it would some time since have become impossible 

 to raise any crop of sugar-cane in the islands. The reason why 

 these natural enemies have not alone got the up])er hand of the 

 hopper is due to various causes. In the first place, a number of 

 the parasites such as the Drvinid Echthrodclphax faircJiihh'i and 

 the ])arasitic flics of the genus Pifiiiiiciiliis are of local occurrence, 

 and in many places cannot (for climatic or other unknown rea- 

 sons) maintain their existence. This was well shown ])y the 

 behavior of the first-named, which was distributed in thousands 

 by the entomologists and the Plantation managers themselves 

 to all the districts in the islands, but in many places did not 

 thrive. Such, too, is the case with the predaceous black earwig 

 (Chclisochcs iiiorlo) which, a natural immigrant to the islands 

 and no doubt acclimatised centuries ago, is found on com])ara- 

 tively few plantations. Other natural enemies are themselves 

 periodically decimated by ])arasites, as is the case with the in- 

 troduced green cricket (Xipliidium varipcnuc), which has its own 

 egg-parasite {Paraplicliiiiis). Other enemies like the common 

 lady-bird (Cocci iiclla re panda) introduced by Koebele years ago 

 for other purposes, i)rey on young leaf-hoppers, in default of 

 more favorite food, and this valual)le predator too is itself sub- 

 ject to parasitic attack by the common Rraconid (Cciifistcs). j\t 

 ])resent the whole number of ])arasites and predaceous insects 

 that attack cane leaf-hop])er to such an extent as to render their 

 services worth noting is considerable, as the following sum- 

 mary shows. 



The most valuable are the four egg-parasites, which there is 

 every reason to hope will become still more effective with rea- 

 sonable time, one (OofcfrasticJius) having as }et had no chance 

 to show its full effectiveness. 



The two Pipunculus flies (P. jiiTafor and tcrryi) are restricted 

 lo certain localities and are native species, wliich have trans- 



