REPORT OF THE ENTOMOLOGIST. 471 



FOOD-PLANTS. 



Original Food-plant of Icerya purchasi. — There seems gooJ 

 reason to believe that this species is originally an Acacia insect, and 

 that upon one or another of the plants of this genus it was imported 

 from Australia into South Africa, California, and New Zealand. 

 Australia is pre-eminently the home of the Acacias, while none are 

 indigenous to California, nor, so far as we can ascertain, to New Zea- 

 land, and, as is well known, the species now found in these two coun- 

 tries have been introduced from Australia. 



Professor McCoy, of Melbourne, in his original communication to 

 the government of Cape Colony, in 1876, stated that the insect in 

 question occurred in Victoria on " different kinds of Acacia," 



Mr. J. C. Brown* states, on the basis of Mr. Trimen's' description, 

 that the "Australian Bug" appears to resemble in several details one 

 of the Coccidae found on the Kangaroo Island Acacia, universally 

 around Adelaide. This statement is so indefinite as to have little 

 weight; yet there is more than a possibility that the Australian insect 

 mentioned is the Icerya. 



Mr. Trimen, in his rej)ort previously mentioned, states that the 

 first specimens seen by him in Cape Colony occurred in 1873, at Clair- 

 mont, oc Blackwood trees {Acacia inelanoxylon) , obtained from the 

 botanic gardens at Cape Town. He goes on to say: 



In the course of a few months the insect increased so prodigiously in number, and 

 the Australian Acacias became laden with them to such an extent, that in the early 

 part of 1874 the large Blackwood trees in the gardens, which were infested to a 

 greater extent than any other plant, had to be cut down. 



In New Zealand the first appearance of this insect was also upon an 

 Australian Acacia. Mr. Maskell, in originally describing the insect, in 

 1878, says: "My specimens of this subdivision were found on a hedge 

 of the Kangaroo Acacia, f in Auckland, in March last. I understood 

 from Mr. Cheeseman and Dr. Purchas, who kindly brought this in- 

 sect under my notice, that it had only lately appeared in Auckland, 

 and that it was only as yet to be found upon that one hedge." 



In California the experience was almost precisely similar. Mr. 

 Stretch, in his paper before the California Academy of Sciences, in 

 1872, stated that at Menlo Park "it seemed to originate upon'^cacm 

 latifolia, a species imjjorted from Australia." Miss Anna Rosecrans, 

 writing to the Pacific Rural Press of February 17, 1877, says: "It 

 was first noticed at San Rafael on Acacia trees four or five years ago." 

 Dr. Chapin, in the first report of the State Board of Horticultural 

 Commissioners of California, 1882, says: "This scale has been, it is 

 asserted, known to be on the Acacia for seven years in San Jos^, but 

 it is only during the past and present seasons that it has attracted at- 

 tention" (presumably by its spread to other cultivated plants). 



Thus we have much cumulative evidence that the species of the 

 genus Acacia are the preferred food-plants of the Cottony Cushion- 

 scale, and, admitting Australia as its proper home, they are probably 

 its original food. 



Its Food-plants in South Africa. — From Mr. Trimen's 1877 

 report we gather the following list of plants to which the Australian 

 Bug had spread since 1873: 



Acacia melanoxylon. 



*0n the "Australian Bug" of South Africa. Journal of Forestry, May, 1883. 

 VI, p. 44. 

 \ Acacia armata. — C; V. R. 



