96 



3. Virgin Gorda. 



This island is about 15 miles east of Tortola. 

 A visit was made to that part of it most remote 

 from Tortola and opposite Anegada, the country 

 at the back of North and South Sounds being 

 explored. Isolated patches of two kinds of 

 prickly-pear were met with, namely, 0. dillenii 

 and 0. ctirassavica taylori. No disease or injuri- 

 ous insect was remarked as being present. 



In approaching North Sound, Prickly Pear 

 Island was skirted, and the same two species of 

 Opuntia noticed growing on it as on the main 

 island, of which it is an outlier. 



Similarly, in sailing for Tortola near ap- 

 proach was made to Great Dog Island and also 

 to Beef Island. On both of these 0. dillenii was 

 noticed growing on exposed, steep, rocky declivi- 

 ties under circumstances that would seem to ex- 

 clude any suggestion that it was not a native 

 plant. 



ST. JOHN. 



Coasting near this island, plants of two 

 species of prickly-pear proper to maritime situa- 

 tions were seen, viz., 0. dillenii and catacantha. 

 W. C. Fishlock, late Instructor in Agriculture 

 for the Virgin Islands, when traversing the island 

 in the interests of this inquiry, and examining 

 whatever prickly-pear plants he encountered, no- 

 ticed an example of 0. dillenii exhibiting a very 

 unhealthy appearance. Specimens secured on 

 the occasion and afterwards submitted by him 

 for inspection served to show that he had before 

 him an instance of a common physiological 

 disease. Dry Rot, already known in Queensland. 



PORTO RICO. 



It was the intention of the Commission to 

 make two visits to this island, one in proceeding 

 to, the other while returning from, the Domini- 

 can Republic. Unforeseen contingencies, how- 

 ever, rendered one of these alone practicable; 

 hence the inquiry was not as exhaustive as it 

 had been hoped. The localities visited were the 

 neighbourhood of San Juan and Guanica, as well 

 as certain coastal districts in the north, west, and 

 south of the island. 



Urban, in his " Flora portoricensis " (pp. 

 432-4), records the following species from the 

 island : — 0. catacantha, Link and Otto ; 0. repens, 

 Bello; 0. curassavica, Miller; 0. tuna, Mill.; O. 

 guanica, Sch. and Gurke, and Nopalea cochineli- 

 fera, L. Messrs. Britton and Rose have examined 

 the Porto Rican species, but have not fully adop- 

 ted Urban 's identifications. 0. repens^ Bello 

 (not Karw.), is regarded by Schumann (1899, 

 p. 749) as a synonym of 0. curassavica, while Dr. 

 Britton has shown that it is 0. stevensiana, Brit, 

 and Rose. Urban 's 0. catacantha is the variety 

 Taylori Br. and Rose, while 0. guanica is the 

 typical 0. catacantha (fide Britton). His 0. 

 tuna is really 0. dillenii. The locality assigned 

 to these species by Prof. Urban is the dry coastal 

 region near Ponce, which is evidently the main 

 cactus area. 



Of the Porto Rican prickly-pears men- 

 tioned, 0. catacantha, 0. stevensiana, and 0. dil- 

 lenii were fqund growing at Guanica, whilst two 

 naturalised species. Nopalea cochinelifera and 0. 



ficus-indica, L., were observed in or adjacent to 

 gardens in various parts of the island. 0. dil- 

 lenii. was also seen to occur in large clumps at 

 Aroeibo on the north coast. 



Occurrence of disease. 



When interviewed, the Entomologists and 

 Mycologists attached to the Sugar Experiment 

 Station and the Board of Commissioners of Agri- 

 culture stated that they were not aware of the 

 presence of any diseases occurring locally. 



The diseases met with in the Guanica dis- 

 trict (Ponce Division) were Shot-hole and the 

 Zone Spot Disease, both occurring on 0. dillenii. 

 A rusty appearance of segments caused by un- 

 suitable conditions was seen occasionally. 



Two coccids were met with in the same dis- 

 trict, one of them Diaspis echinocacti, Bouche, 

 being quite prevalent near Guanica on all kinds 

 of prickly-pear, as well as on two species of 

 Cereus seen there. In some places it had 

 seriously injured the Cereus spp., but was evi- 

 dently assisted in its destructive work by the 

 very arid conditions prevailing there. 



In this locality there was found a much 

 more conspicuous coccid, one which had not been 

 previously met with. In places, plants of 0. dil- 

 lenii were whitened by the presence of this 

 large active insect, whose body, when ecdysis had 

 recently taken place, was brownish dorsally with 

 lines of bright red circular spots, whilst at other 

 times it was covered with a dense mealy excre- 

 tion which was also plentifully sprinkled over 

 the green surface of its host plant. The small 

 male insects in their larval and pupal conditions 

 were present in much larger numbers than their 

 consorts. 



This peculiar coccid had attacked, in addi- 

 tion to 0. dillendi, two Cereus plants growing 

 where it occurred, but in neither case did it ap- 

 pear to occasion any marked injury. It was, 

 however, evidently parasitised by some hymenop- 

 terous insect ; a fact that would, of course, serve 

 to lessen the injuries that might otherwise result 

 from its presence. In some cases it was found 

 associated with Zone-spot Disease, and at times 

 under conditions that might suggest that it had 

 served as the inoculating agent, since it, like other 

 coccids, punctures its host-plant and then extracts 

 its juices. As this parasite does not seem to have 

 been treated of in entomological literature relat- 

 ing to prickly-pear, specimens were submitted to 

 Dr. L. 0. Howard, Chief of the Bureau of Ento- 

 mology, Washington, D.C., for an opinion as to 

 its identity and its plant relationship, but no in- 

 formation has as yet been received. It was 

 evidently related to Icerya, differing from it, 

 however, in not producing an ovisac. 



SAN DOMINGO. 



Although the ocurrence of prickly-pear (0. 

 dillenii) is reported from many points along the 

 lengthy coastline of the Republic of San 

 Domingo, there are special districts where 

 OpuntisB and other Cactacese are especially preva- 

 lent. Two of these are Monte Christi near the 

 western, and Matanzas towards the eastern ex- 

 tremity of the north coast, and the other is be- 

 tween Ba,ni, Azua, an^ Barahona, on the south 

 coast. The latter of these only was explored by 



