107 



The joint may become hollowed out to such 

 an extent that only the spines and epidermis 

 are left either dry or as a bag containing a 

 putrid dark fluid. At othei* times a black, 

 more or less spongy mass remains in the place 

 of the tissues. It is quite common to see whole 

 branches, or even entire plants, killed. Sometimes 

 the attacked joint collapses and then the distal 

 segments may come in contact with the ground 

 and grow. The effects pf this moth, assisted no 

 doubt by the scavenging diptera, can be seen very 

 commonly in the arid country surrounding Men- 

 doza and extending up the Andes for many miles 

 on each side of the transandine railway line. 



The effect 'on the invaded segment and the 

 appearance of the insect excreta reminded one 

 strikingly of what was found as a result of the 

 attacks of Melitara spp. on Prickly Pears in the 

 dry zones of the United States. 



The host-plants are 0. sulfurea especially, 

 and quite commonly both species of Cereus which 

 abound on the Cerro Pilar, near Mendoza, are 

 attacked. It is exceptional to find 0. {Tephro- 

 cactus) diademata invaded, this being perhaps 

 due to its tougher epidermis. The Cereus spp. 

 are hollowed out in a similar manner to the 0. 

 sulfurea. In the latter case the injury commonly 

 extends from joint to joint and may involve the 

 portions below ground. Old and young joints 

 alike are attacked. 



At Mendoza no plants other than Cactaceie 

 were noticed as being attacked in a similar man- 

 ner to that described above. 



A prolonged search of several days failed to 

 reveal more than a few of the grubs at work 

 (early February, 1914). They were seen to 

 resemble the Zophodia larvee in size, but lacked 

 the colouring and transverse bands of the latter. 

 Two cocoons with pupee were found, one in a 

 hollow joint of 0. sulfurea and the other under a 

 segment lying on the ground. One of these bred 

 out into a grey moth of the same size and naked- 

 eye appearance as the Zophodia. 



Undetermined Larva. — A small insect larva 

 about 14-inch in length, with a cream-coloured 

 body and a reddish-brown head was found on a 

 few occasions on 0. sulfurea near Mendoza, living 

 in a cavity or tunnel which it had eaten out 

 underneath a mass of cochineal in each case. 

 The base of a joint was the situation which 

 seemed to be preferred. A loose web was also 

 present. As dead cochineal insects were seen in 

 each instance and as the head of the larva was 

 sometimes stained with cochineal dye, it may 

 be that the larva was predatory on that insect. 

 Sometimes the tunnels were fairly extensive and 

 then the debris was like that produced by the 

 Mendoza moth. Whether the larva belonged to 

 the latter or whether it was an enemy of the 

 coceid, was not satisfactorily determined. 



CEcETicus PLATBNSis, Berg.— This ^^small 

 larva, which lives in a conical " house ^ and 

 is popularly known in Argentina as bicho 

 de canasto," was found feeding on the sur- 

 face of joints of 0. decumana cultivated by 

 Dr. Spegazzini at La Plata. It commonly causes 

 the destruction of young segments, but those 

 which are rather older recover, the injury healing 

 over and a scar being produced exactly like tnat 



caused in Texas by Mimorista flavidissimalis, 

 Grotc, on 0. luidJicimerl and other species. On 

 account of the destruction of young joints this 

 insect, like the j\liiaorista, evidrntly assists in 

 controlling the spread of Opuntias. 



Similar injuries were seen on 0. sulfurea near 

 ]\Ieiidoza, and the same remark applies also to 0. 

 culpa and the " spmy palmadora" at Bomfin and 

 Angieo (Bahia), where a considerable destruction 

 of young joints had evidently taken place, especi- 

 ally in the case of the last-named plant. However, 

 in these instances no insects were found associated 

 with the condition and there is no direct evidence 

 as to the kind of insect producing them. 



Wild Cochineal, Coccus spp. — A species of 

 wild cochineal was found to be rather common 

 on 0. sulfurea in the neighbourhood of Mendoza. 

 Though sometimes found in abundance on a 

 segment of 0. sulfurea, no injury beyond a slight 

 chlorosis was recognisable. It should be men- 

 tioned, however, that the coccids were being 

 preyed on by other insects. A description of 

 Coccus argentinus, Dominguez, 1907, which is 

 said by Autran to feed on 0. ficus-indica and 0. 

 aurantiaca, was not available for comparison. 

 Dr. Spegazzini informed us that a wild cochineal 

 occurs also at Santiago del Estero, but he did 

 not mention the host species. 



Another species of cochineal insect which 

 seems to be rare, was found at Angieo in the 

 State of Bahia, in North-west' Brazil, on the spiny 

 Opuntia which is frequently encountered there. 

 It has the woolly appearance common to all ' ' wild 

 cochineals, ' ' as distinct from the true Coccus cacti 

 L. No injury appeared to be occasioned by the 

 presence of the insect. From specimens obtained, 

 there have bred out a hymenopterous parasite 

 (Ichneumonidte) as well as diptera belonging to 

 the Stratiomyiidas. Hempel, in his work on 

 Brazilian Coccids (1900), does not refer to the 

 last-mentioned cochineal, but mentions only 

 Coccus cacti, Lin., as occurring in Brazil. 



One member of this Commission has shown 

 that the Wild Cochineal (Coccus indicus, Green), 

 which has been so destructive to O. monacautha in 

 India and Ceylon, was first introduced into India 

 by a Captain Neilson, who brought it from Brazil 

 (Tryon, 1910, 1911). This matter has since been 

 referred to in the Commission's report on the 

 investigations in India, as well as in a paper bv 

 Mr. E. E. Green (1912, p. 87). Inquiry in Rio 

 de Janeiro failed to gain any information regard- 

 ing the occurrence of any Coccus on 0. mona- 

 cantha, a plant indigenous to Southern Brazil 

 and adjacent wooded country in Uruguay and 

 Argentina. In India and Ceylon the insect is 

 found to live only on that species, while the 

 fillied variety, C. capensis, from Cape Colony, 

 attacks only that species and Nopalea cochineli- 

 fera. It would thus seem reasonable to believe 

 that 0. monacantha is at least one of the host 

 plants. Perhaps a careful search in Southern 

 Brazil (Sao Paulo and Rio Grande do Sul) might 

 reveal its presence. The Argentine species from 

 Mendoza would not make any attempt to leave 

 its special host-plant in order to feed on segments 

 of 0. monacantha placed in the same box. There 

 is the possibility that C. indicus* is not a South 

 American species at aU, but that it may have 



* This matter has been referred to earlier in the 

 sections dealing with India and Mexico. 



