34 



chlorosis in-oduced by individual insects is negli- 

 gible when compared witli what is occasioned in 

 those regions by the latter variety. The experi- 

 ence of C. Lounsbury and of his colleague at the 

 Cape, C. W. Mally, is that attacked plants are 

 not killed liut are made sickly, recovering when 

 congenial climatic conditions return. It would 

 appear, then, that some influence of climate may 

 account for the difference in the mode of action 

 of the Wild Cochineal Insects in India and South 

 Africa respectively. In the latter region, at anj' 

 rate, it appears to exert some influence in pre- 

 venting the increase and spread of the plant it 

 affects — one identical with the Suttor River 

 " pest pear " of Queensland. 



In order to test whether this difference in 

 result was due to the presence of some cheek 

 operating against the South African Cochineal, 

 specimens of the latter were kept under observa- 

 tion by the Commission and by Messrs. Louns- 

 bury and Fuller at Pretoria, but no parasites were 

 found to be present in the material obtained 

 locallj'. In Capetown, however, G. capensis is 

 commonly preyed upon by a Ladybird Beetle 

 identified by Mr. C. Lounsbury and by Mr. Mally 

 as Exocomus nigromaculatus. This was seen in 

 abundance feeding on the insect in that locality. 

 No parasitic hymenoptera, diptera, &c., were 

 found, though frequently looked for. 



Despatch of the Cape Wild Cochineal to 

 Queensland. — A small consignment of C. capensis 

 was collected by the Commission and forwarded to 

 Q,ueensland by Mr. C. W. Mally, the Cape Ento- 

 mologist. This arrived in July, 1913, and, 

 according to Dr. Jean White's recent report 

 (1914), has led to the establishment of the species 

 in our State, the small consignment of C. capen- 

 sis which was forwarded on Nopalea from Ceylon 

 having died out. 



It may be pointed out, in dealing with the 

 Wild Cochineal Insects — different forms of the 

 species Coccus confusus named indicus and 

 capensis— reierred to in this Report, that their 

 exclusive plant-relationship is well known to all 

 entoraologists. Moreover, so special is their dietary 

 that it may be confined to a few species within 

 the cactaceous genus that they affect. A member 

 of -the Commission has already dwelt upon the 

 " question as to the harmfulness to vegetation 

 other than Prickly-pear following the introduc- 

 tion of the Wild Cochineal" (Tryon, 1910). In 

 fact, the great Alexander Humboldt, writing 

 nearly a hundred years since, used this feature 

 m their economy as suggestive of the fact now 

 known — tliat the insects comprised under the 

 term Grana fina (Precious Cochineal) and those 

 designated Grana sylvesire (Wild Cochineal) 

 were distinct species of Coccus (Humboldt, 1818, 

 p. 432). This matter is dwelt upon to allay any 

 suspicion that may arise that the Wild Cochineal 

 cannot be introduced to a new country (eg 

 Australia) without prejudice to other vegetation 

 than Prickly-pear plants. 



_ Establishment of the Ceylon Wild Cochineal 

 tn South 4/nca.— The Commission supplied to 

 the Entomological Division of the South African 

 Department of Agriculture, Pretoria, and also 

 to the Cape Entomologist, colonies of Coccus 

 indicus from the Henaratgoda Station, Ceylon 

 Part of this material was handed over to the Natal 



Museum, where the insects were propagated, the 

 result being reported on by Dr. E. Warren (1914, 

 p. 387) in a recent number of the South African 

 Agricultural Journal. The common species of 

 Prickly-pear, the Doornblad (called 0. tuna by 

 him), was found to remain unattacked, while 

 0. monacantha was seriously affected, some plants 

 being destroyed (p. 390). He considered that 

 these insects may be of use in keeping the prickly- 

 pear within bounds, and that if they can stand the 

 winter climate and also remain free from attacks 

 by their own enemies, that they might become 

 sufficiently numerous to cause the extermination 

 of the latter Opuntia. A summary of this paper 

 has appeared recently in the Review of Applied 

 Entomology (Ser. A, vol. 2 (7), July, 1914, p. 

 440). 



The True Cochineal. 



The true Cochineal {Coccus cacti) thrives in 

 the Capetown Municipal Gardens on 0. tomen- 

 tosa, Nopalea cochinelifera, and 0. decumana; 

 but it exists rather as a curiosity. Though intro- 

 duced from the Azores about 1880 (fide Dr. 

 Peringuey of the Capetown Museum) , it has not 

 been the means of destroying any of the plants.* 



Diaspis, sp. 



A species of Diaspis was found attacking 0. 

 monacantha at Capetown and 0. decumana 

 (Kaalblad and Doornblad) in various parts of 

 Cape Colony (Bedford, Cradock, Cookhouse, 

 Graaff Reinet, &c.) ; but though the degree of 

 infection was sometimes considerable and had 

 been operating for many years, yet no detri- 

 mental effect was noticed. In one case, near 

 Graaff Reinet, Diaspis was very common, and, 

 though acting for sixteen years (fide Mr. R. W. 

 Thornton), had not caused any disease or 

 " leaf " destruction. The experience of Mr. 

 Lounsbury and Mr. Mally confirms the Commis- 

 sion's finding. 



DESTRUCTION BY NATURAL ENEMIES. 



Disease. 



The Commission interviewed at Pretoria Mr. 

 Pole Evans, Plant Pathologist to the Union of 

 South Africa, with reference to the possible 

 occurrence of diseases of the Prickly-pear and 

 to the question of utilising any that might be 

 found to occur in the subjugation of these plants. 

 He stated that he had not met with a single fungus 

 parasite on Opuntias in South Africa; also, that 

 he had not seen or had brought under his notice 

 any Priekly-pear disease. Where specimens pre- 

 sumed to be disease-affected had been submitted 

 to him, the appearances presented had been found 

 to have been occasioned by insects. The Opuntias 

 in South Africa commonly grew in such arid 

 areas that the occurrence of fungi in association 

 with them was little to be expected. Regarding 

 the inquiry from the point of view of the plant 

 pathologist and mycologist, there did not appear 

 to be much hope from what might be discovered 

 m the Union. However, the Aloe, a plant that, 

 like the Opuntia, was met with in comparatively 



' Green (1912, p. 84) refers to the presence of Coccus 

 each at the Cape, where Mr. Lounsbury informea him that 

 It grew on 0. tuna, a species which, Burkill stated, did not 

 occur there. The confusion regarding the identity of 

 O, tuna has already been mentioned in this report. 



