CACTUS-FEEDING INSECTS AND MITES 63 



the buds, flowers, young fruit, and young growth of prickly pears. 

 At Carmen de Patagones, in Rio Negro, and in the Sierra de la 

 Ventana, in the south of Buenos Aires Province, the larvae were very 

 destructive to the fruit of 0. sulphurea and 0. bonaerensis in January, 

 while flowers and young fruit of 0. sulphurea were heavily attacked at 

 Mendoza in December. As a fruit enemy this insect behaves much like 

 . fuscomaculella clarefacta in Texas. The flower head is entered first and 

 is attached to the fruit by silken strands. Entrance to the fruit is made 

 through the center of the crown, and either the ovary or the fleshy 

 portion is eaten. Larvae often occur in the dead flowers. 



0. sulphurea, 0. bonaerensis, and 0. utkilio have been recorded as 

 direct host plants. Where cochineal has been the host, the larvae 

 have been observed on many prickly pears including, in addition to 

 the three plants already named, 0. discolor, 0. quimilo, and various 

 species related to 0. monacantha and 0. bonaerensis. 



As larvae have been observed almost throughout the year, it is 

 probable that there are at least three generations annually. The 

 larvae are grey-green or black-green in color. The loose white cocoons 

 occur among debris around the plants. Adults have been reared in 

 January, February, and March. The wing expanse is approximately 

 one inch; the forewings are dark grey-brown with a rather broad, 

 somewhat white stripe along the anterior margin; the hindwings are 

 pearly white, with the outer edges lightly dusky. 

 Parasites. — The insect suffers heavy mortality from the attack of the 

 braconid Apan teles alexanderi. 



SIGELGAITA Heinrich 



Heinrich erected this genus in 1939 for the reception of three new 

 species from Peru and Chile. The larvae are fruit feeders. 



Sigelgaita chilensis Heinrich 



This insect was discovered in late 1936 and early 1937 at La Serena 

 and Ovalle, in the more northern section of Chile. The blue or blue- 

 green larvae occur commonly in December and January in the fruit 

 of Eulychnia acida and Trichocereus chiloensis and destroy a large pro- 

 portion of the fruit in some areas. They enter the fruit at the base and 

 tunnel into the seed cavity. Frequently the infested fruit rots, and the 

 larva transfers to an adjacent fruit; thus several fruit may be destroyed 

 by one individual. When full-grown the larva lowers itself to the 

 ground by a thread and among the debris spins a frail cocoon containing 

 white air globules. 



