106 



9. 0. cinoryi — cultivated at Buenos Aires. 

 A plant under this name in the 

 Palermo Botanic Gardens was found 

 to be attacked. The specimen ap- 

 peared to be a typical 0. aurantiaca, 

 which is a native of Uruguay and 

 occurs naturalised near Koma, Queens- 

 land. 0. emoryi as described by Schu- 

 mann (1899, p. 664) is a different 

 plant whose habitat is Norther a 

 Mexico and the adjacent dry parts of 

 Arizona. 



10. It was found experimentally that it 



would feed on 0. cuipa, from North 

 eastern Brazil, though not partial to it. 



11. The pest pear of Oahu (Hawaiian 



Islands) is readily attacked and since 

 this white twisted-spined species is 

 related to the 0. ficiis-indica group and 

 is very much like the WestAvood pear 

 of the Rockhampton district, there is 

 no doubt that it will prove an enemy 

 to it as well as to the related Yellow 

 Mexican pear which occurs sparingly 

 in the same district. 



12. Since arrival in Queensland it has been 



found to be able to attack the common 

 pest pear of the Brisbane district. 



Berg, in his original account, mentioned that 

 the larva of Zophodia cactorum was taken in 

 fiowers of I^Mpsalis lumbricoides, S.D'.,_ in 

 Uruguay and on Opuntia sp. in Buenos Aires. 

 He stated that this species was closely related to 

 Z. hollii Zell, and was indigenous to Uruguay and 

 Argentina. Dr. Spegazzini, who indicated to the 

 Commission the presence of this insect at La 

 Plata, mentioned that it was more common in the 

 former republic. 



The account given by an anonymous writer 

 in the " Chronica Agricola" for 1908 (p. 147— 

 quoted by Tryon, 1911, p. 19) of a boring insect 

 enemy of the Prickly Pear shows that the same 

 organism is being referred to. Its destructive 

 effects on Opuntias are there regarded as being 

 sufficiently serious to give rise to a suggestion 

 that measures should be taken to cope with it. 



Zophodia cactorum, as far as we have been 

 able to ascertain, is restricted to cactaceous plants 

 for its food supply. 



It should be mentioned that another species 

 of Zophodia, Z. dilatifasdella, Ragonot, has been 

 identified from various localities in Texas, where 

 it is said to feed on Coccus confusus. the common 

 wild cochineal of that region. (Hunter, Pratt, 

 ;ind Mitchell, 1912, p. 46.) 



A consiclerable number of more or less fully- 

 grown caterpillars and a supply of 0. decumana. 

 one of its food plants, were collected at La Plata 

 towards tlio end of last January, and about a 

 week later many of them had pupated. A fair 

 proportion, however, failed to do so, this being no 

 doubt due to injury during transportation. As 

 already stated above, about three weeks was spent 

 in the chrysalis stage. Some of the moths laid 

 "egg sticks," and it was from these eggs that 

 the specimens Avhich the Commission brought to 

 Queensland were hatched. 



This introduction of the insect to Queens- 

 land has not, however, resulted in its establish- 

 ment there. This apparently is the outcome of 

 certain of its habits being unknown and accord- 

 ingly not taken into consideration. The cater- 

 pillars in question had originally issued from eggs 

 about the end of March just before the arrival 

 of the Commission at Honolulu, and were fed on 

 segments of 0. monacantha, 0. cuipa &c., until 

 that port was reached, when they were given 

 joints of the Opuntia prevalent there to feed 

 upon. This they partook of with characteristic 

 activity. On arrival at Sydney at the end of 

 April they were still in the caterpillar condition 

 and feeding. Thence they were transmitted to 

 Queensland. Here the employment of the Hono- 

 lulu Prickly-pear was continued for awhile, but 

 it having been meanwhile found that they would 

 feed on the common local Opuntia (0. inermis) 

 this was soon substituted, and they proved only 

 slightly less partial to it than the Honolulu pest 

 pear. However, they constantly emerged from 

 the interior of the stem-joints, and wandered 

 around spinning a little silk as if to pupate. They 

 did not, however, on these occasions turn into the 

 chrysalis condition, but gnawing into fresh 

 "pear" resumed their feeding. This they did 

 again and again. It was evidently, from what 

 was afterwards inferred, the display of an attempt 

 on their part to overwinter, but the temperature 

 experienced during our so-called cold months 

 was evidently not sufficiently low to promote the 

 condition of lethargy that for their overwintering 

 as caterpillars was essential. It was considered, 

 however, that their temporary abandonment of 

 the Opuntia joints was due to decay of the tissue 

 surrounding that in which they subsisted in 

 accordance with the requirements of a habit com- 

 monly pursued, and accordingly they were not 

 provided with especially cold quarters. Under 

 the circumstances they became weaker and weaker 

 and died off one after another, usually outside 

 the plant in which they had thrived. Two even- 

 tually spun cocoons but were not able to trans- 

 form to chrysalides, and succumbed within these, 

 becoming dried up. However, they had lived 

 several months, and now (8th October) after this 

 protracted period of activity the forty examples 

 brought to Brisbane by the Commission have 

 been reduced to three. This has resulted notwith- 

 standing the fact that the insects had been cared 

 for by one of the Commission personally and by 

 (wo of his assistant entomologists since their 

 arrival here. 



It has, however, been established that Zopho- 

 dia cactorum will feed upon the common "Pest 

 Pear" of Queensland and is destructive to it, 

 possibly to the extent exercised on other Opuntias 

 in its native country, but that under our condi- 

 tions it apparently would undergo very slow 

 numerical increase. 



Dr. C. Spegazzini, La Plata, Argentina, has 

 kindly offered to assist, if desired, in forwarding 

 specimens of this formidable enemy of so many 

 of the CactaccfE. 



The Mendoza Moth Borer. — The injury 

 produced by the larva of this moth is similar 

 to that caused by Zophodia. The excreta, how- 

 ever, are yellowish or brownish and are dry. 

 The rotten condition previously noted, together 

 with abundant fly infection, is very common. 



