70 U.S. NATIONAL MUSEUM BULLETIN 256 



Ozamta hemilutella Dyar 



The larvae of this Argentine insect are fruit feeders with habits very 

 similar to those of 0. fuscomaculella clarefacta in Texas. Akhough rather 

 widely distributed, the species does not seem to be prevalent, since 

 there are not many records of its occurrence. The species was described 

 from material reared from larva attacking fruit of Cereus validus at 

 La Rioja, Argentina, in January and February 1921. In February 1925 

 fruit of the same plant were infested at Tacanitas, Province of Santiago 

 del Estero, but the several species of Opuntia in the vicinity appeared 

 to be immune from attack. During the more intensive investigations 

 in the Argentine in 1931 to 1933, larvae were collected in fruit of 

 Opuntia quimilo in the Province of Santiago del Estero and in one of 

 the 0. monacantha group in the neighbouring portion of the Chaco. 



The olive-green larvae have been recorded in February, April, 

 June, August, and November; moths have been reared in February 

 and December, and eggs have been seen in the field in February. 

 Thus, there may be at least three generations annually. In the case of 

 Cereus validus, the pink eggs were laid singly on the outer scales of 

 the flower buds; the larvae entered the fruit near the base and tun- 

 nelled into the seed cavity; later they attacked the fleshy portions, 

 and the fruit dried up. On Opuntia quimilo the larvae occurred in the 

 flowers and the crown of the fruit, many of which were destroyed. 



The moth has a wing expanse of 27 to 30 mm.; the forewings are 

 grey with a clear yellow inner area, and the hindwings are white. 



Ozamta punicans Heinrich 



This Argentine form, described in 1939, is considerably larger than 

 other members of the genus, and the larvae are stem borers. It is 

 known from one locality only: Tapia, Province of Tucuman. How- 

 ever, as will be mentioned later, its distribution may be much more 

 extensive. 



Olive-green larvae were found at Tapia in Septembei^October 

 1933 and again in August 1936, living solitarily in rather large cells 

 in the stems of Cereus validus. They spun cocoons within the larval 

 cavities and produced moths in the second half of October in both years. 



The adult has a wing expanse of 36 to 44 mm.; the forewings are 

 light grey with several yellow blotches; tlie hindwings are white with 

 slight fuscous shading. 



In April and May 1937 very similar larvae were located in the stems 

 of C. validus or a close ally, at Paso de los Libres, Province of Entre 

 Rios, Argentina, and of the related C. alacriportanus at Rio Grande do 

 Sul, Porto Alegre, and Pelotus, State of Rio Grande do Sul, southern 



