THE CACTUS-FEEDING PHYCITINAE — HEINRICH 357 



Type. — Location unknown. 



Type locality. — Argentina. 



Food plants. — Opimtia {Platypuntia) spp. Apparently limited to 

 the Platypuntias. 



Distribution. — Argentina : La Plata, Concordia, Tacanitas, Santi- 

 ago del Estero. Uruguay: Piriapolis. Australia (introduced and 

 established) . According to Dodd '"'•cactomum is a native of Uruguay 

 and the northern Argentine provinces of Entre Rios, Corrientes 

 Sante Fe, Santiago del Estero, Tucuman, Salta, and Chaco." He also 

 includes Paraguay and southern Brazil in its possible range; but we 

 have no adult specimens from the latter localities. 



Thirty-five specimens examined. 



Remarks. — This is the species that has been used with such re- 

 markable success in the biological campaign against the pricklypear 

 in Queensland and New South Wales. In 1925, when some 2,750 

 eggs of cactomm were taken to Australia for rearing and distribu- 

 tion of the moths, about 60,000,000 acres had been overrun by prickly- 

 pear. By 1936 "approximately 25,000,000 acres of good grazing and 

 agricultural land, previously a wilderness of dense pricklypear, had 

 been retrieved to such an extent that they are rapidly being de- 

 veloped and brought into production. The remarkable results are 

 due to the activities of one insect, the Argentine moth-borer, Gacto- 

 hlastis cactoinim Berg." Dodd's 1936 paper gives a detailed and 

 moving account of the great campaign, probably the most spectacular 

 in the history of economic entomology. 



The species seems to be definitely established in Australia. 



Descriptions of the larva are given by Berg and Eagonot. They 

 are detailed and accurate but apply to the genus rather than to 

 cactorum specifically. 



2. CACTOBLASTIS RONNAI (Brethes), new combination 



Neopyralis ronnai Brethes, in Ronna, Chacaras e Quinaes, vol. 20, no. 1, p. 18, 

 1920. — Costa Lima, Terceiro catalogo dos insectos que vivem nas plautas 

 do BrazU, p. 268, no. 1031, 1936. 



The description of Brethes's supposed new genus and new species 

 is misleading, and the placement of them in the Schoenobimae obvi- 

 ously an error. Roima states that the species was reared from cater- 

 pillars feeding in spineless cactus in Rio Grande do Sul. They are 

 described as clear yellowish, with black transverse bands or rows of 

 black spots on each segment. This description can hardly apply to 

 any cactus larva other than Cacfohlastis. Dodd writes that "Mr. 

 Mundell carried out investigations in Rio Grande do Sul and Santa 

 Catherina in May 1937. The only larva found attacking pricklypears 

 was a Cactohlastis, which was generally distributed and often com- 



