The Planters' Insect Friends. 39 



The gangs which estates employ to cut out the Diatroea caterpillars 

 from " dead hearts " destroy a number of this useful parasite. When 

 they cut open the "dead hearts" in search of the Diatroea caterpillars, 

 larvae and pupae of the parasite, if present, often get fatally injured, or 

 the larvae are put into the tins where they perish among the heaps of 

 writhing caterpillars. Such destruction is unavoidable, as it is impossible 

 to tell without cutting it open whether or not a " dead heart ! ' contain a 

 parasite. Even the mere displacement of the parasite larvae generally 

 means its death since it is, as already stated, usually unable to regain its 

 hold on the caterpillar. 



Two other species of Iphiaulax, besides Iphiaulax medianus, are 

 seen in canefields, and they are probably parasites of Diatroea or of some 

 other cane-pest. 



Cremnops parvifasciatus, which the local Museum possesses a male 

 named by Cameron, is also a Braconid parasite on Diatrcea caterpillars. It 

 is not as common an insect as Iphiaulax medianus. It is red with the 

 thorax largely black. 



An Ichneumonid parasite of the caterpillars occurs in a species of 

 Mesostenoideus, but it is rare. 



It may be of interest to mention that the adult Iphiaulax and Crem- 

 nops feed on the moist ends of seeds of the razor-grass, a species of 

 Paspalum. Iphiaulax I have also observed sipping up the honey-dew 

 which drops on leaves of plants infested by scale-insects (Coccidae) and 

 white-fly (Aleurodidae). 



The big black ant known as the kop-kop carries off Diatroea cater- 

 pillars which happen to be met with strolling abroad as they sometimes 

 have to do when seeking fresh food. A single ant is strong enough to 

 walk off with a caterpillar, which resists with all its might, contorting itself 

 and frequently clinging desperately to various objects encountered en 

 route to its captor's abode. 



Another bla?k ant abundant in many cane-fields is the " running ant," 

 probibly identical with the one which often infests houses. Quite recently 

 I saw a number of them devouring a fresh Diatrcea egg-cluster, so that 

 they must be regarded as beneficial. 



The practice, which so widely obtains, of burning the trash from the 

 canes destroys large numbers of both these useful ants, as both often nest 

 under the clasping bases of old dry blades. 



The larvae of Carabid beetles are predaceous, and three or four times 

 I have come across one of these larvae attacking Diatroea caterpillars in 

 their tunnels. They are active creatures, and roam about, when necessary, 

 in search of their prey. 



Metamasius hernipterus, the weevil-borer which attacks cane-tops, 

 stems and shoots at weak points, has a hymenopterous parasite in the 



