126 



Prickly-pears were found to be little, if at all, adversely affected by 

 insect enemies in the Mediterranean region, the Canary Islands, and 

 Hawaii, and only to a slight extent in the West Indies and in most 

 of the localities in South America which were visited. In Ceylon, 

 India, and South Africa, only one species, Opuntia monocantha, was 

 controlled in this way, the agent being in each case wild Cochineal 

 insects [see this Revieiv, Ser. A, ii, p. 440]. In the first two countries 

 the attacks of Dadylopius (Coccus) confiisus indicus had been so 

 disastrous to the host plant that extermination had been practically 

 brought about. The other naturalised species in India, 0. dillenii 

 and 0. nigricans, and in Ceylon, 0. dillenii, were not attacked. 



The most important insect enemies of cacti in America, including 

 those in the United States [see this Review, Ser. A, i, p. 78] are discussed 

 at length, and it is recommended that, for the time being, the following 

 insects be introduced into Queensland : the Longicorn beetles, Monilema 

 spp. and Coenopaeus palmeri ; the weevil, Gerstaeckeria hubhardi ; 

 the moths, Melitara spp. and Mimorista flavidissimalis ; the Coreid 

 bugs, Chelinidea spp. and Narnia spp. ; the wild cochineal insects ; 

 Cecidomyia (Itonida) opuntiae and Asphondylia opuntiae; all from 

 the United States ; Cactohlastis [Zophodia) cactorum, Berg, (Argentine 

 moth-borer) and another Phycitid, the Mendoza moth-borer, from 

 the Argentine. 



The Commission has already introduced into Queensland certain 

 destructive wild cochineal insects, Daciylop>ius {Coccus) confusus 

 indicus, from Ceylon, and D. confusus capensis, from South Africa. 

 These have become estabUshed, and have maintained their destructive 

 character at the Prickly-pear Experimental Station, and should exert 

 a powerful influence in controlling 0. monocantha. Cactohlastis, which 

 is destructive to a large number of prickly-pears, including several of 

 the Queensland species, was also brought to that State, but most of the 

 larvae have died. 



The insects whose introduction is recommended may prove more 

 harmful to cacti in AustraUa than in their native homes, where 

 they are more or less controlled by predators and parasites, and there- 

 fore cannot exercise their full influence. It is consequently a matter 

 of great importance that these parasites should have been ehminated 

 before admission into Queensland. The necessity for provisions by 

 the Queensland Government, so that any of these introduced insects 

 may receive on arrival the proper care and attention needed for their 

 propagation, is emphasised. 



The true cochineal insects, Dactylopius coccus and its congeners, 

 are very closely associated w4th the Cactaceae and will often only 

 live on a particular species of prickly-pear. For example, D. coccus 

 will only subsist on Opuntia cochinelifera, Miller, and will not attach 

 itself to Nopalea cochinelifera, L.,to which Dactylopius confusus newsteadi 

 is confined. Similarly, D. confusus capensis. Green, is restricted, 

 so far as is known, to 0. monocantha, [see this Review, Ser. A, ii, p. 440]. 



A number of other insects attack the prickly-pears, though they are 

 not confined to them, including : Ceratitis capitata, Wied. ; the two mealy 

 bugs, Pseudococcus obscurus, Essig, and Rhizococcus tnultispinosuSy 

 Kuhlg. ; the Cuban cactus Coccid, Palaeococcus sp. ; the Capsid bug, 

 Stylopidea picta, Uhler ; the Scarabaeid beetle, Trichochrous texanus, 



