68 U.S. NATIONAL MUSEUM BULLETIN 256 



The third generation larvae behaved in a manner similar to that of 

 the biilk of second generation. Because of the greater maturity of the 

 fruit, development was more rapid. The life cycle was completed in 4 

 to 5 weeks, moths appearing from the end of August to the middle of 

 September. 



The fourth generation attacked the ripe fruit and completed develop- 

 ment in approximately 6 weeks. Emergence took place in October, but 

 occasional individuals emerged at inteivals throughout Novem.ber. 



Observations on the life cycle and behavior of the fifth generation 

 were not completed. However, it was learned that the larvae developed 

 rather slowly in the ripe fruit, which gave no indication of their pres- 

 ence other than a slightly shrunken area covered with a tough white 

 scab. In the cages small larvae occurred in late October; in the field 

 small larvae were found in late December, but large larvae were 

 seen a month earlier. It is thought that some larvae pupate, or at least 

 spin cocoons, before the end of December, remaining as pupae or 

 unpupated larvae for about four months, and that other larvae continue 

 to develop slowly through the winter months; in either event the moths 

 emerge in spring, which would be April in the Uvalde district. 



The presence of larvae of the first generation is readily discerned 

 because of the webbing around the entrance hole and the rapid decay 

 of the fruit. But in the attack on well-developed fruit by later genera- 

 tions, the occurrence of larvae may be overlooked, since there is little 

 outward sign of the infestation, and the ripe fruit tend to fall to the 

 ground. Hence, general field observations reporting the prevalence of 

 larvae from April to June and their scarcity from July to November 

 have not given a true indication of the position, inasmuch as more 

 intensive search would have been required in order to estimate the 

 Ozamia population after the middle of summer. 



The adult has a wing expanse of approximately one inch. The fore- 

 wings are grey with darker markings, and the hindwings are pearly 

 white with a narrow dark costal line. In fresh examples the thorax and 

 basal half of the forewings have a definite green tint. In confinement the 

 moths lived for 2 to 4 days. They feed readily on dilute honey water, 

 a habit which contrasts with that of other cactus phycitids of the 

 genera Melitara, Cacloblastis, and Olycella, the moths of which do not 

 require nourishment. 



The pale pink eggs are deposited singly on the fine spicules on or 

 near the base of the fruit. The incubation period occupied about 5 

 days in May and 3}^ days in June. No information was obtained on the 

 fecundity of the females. 



The young larvae of the first generation are somewhat white; later 

 they are pink or wine-colored and become dull black in the last instars. 



