40 U.S. NATIONAL MUSEUM BULLETIN 256 



additional localities. Officers of the Board have reported the occur- 

 rence of Olycella larvae practically throughout Mexico from Chihuahua 

 in the north to Oaxaca in the south. The specific identity of the larvae 

 has not been ascertained in most cases. However, material from San 

 Luis Potosi, where the life history received some attention, was identi- 

 fied as 0. nephelepasa. Probably this is the Central Plateau species, 

 represented by larvae found in the States of Chihuahua, Durango, 

 San Luis Potosi, Aguascalientes, Jalisco, Michoacan, Morelos, southern 

 Puebla, and possibly from Oaxaca. It is thought that larvae from 

 lower elevations in southern Mexico, Vera Cruz, the less elevated 

 portions of Puebla, and Guerrero, may belong to another form, 

 possibly . junctolineella pectinatella. 



The Mexican plateau form attacks many kinds of tree pears of the 

 Opuntia tomentosa, 0. streptacantha, and 0. robusta types, as well as shrub 

 pears such as 0. cantabrigiensis. 



The adult is a darker grey moth than Olycella junctolineella. The 

 larvae have very similar habits. The individual eggs are of larger 

 dimensions. Apparendy the eggsticks contain fewer eggs; among many 

 sticks the largest contained 7 eggs, and the average number was 4. 

 The heavy mortality among the young larvae has been observed in 

 this species as in its ally. 



At San Luis Potosi there appeared to be two generations annually, 

 with considerable overlapping. Larvae pupated from March to July 

 and again from October to January; adults were reared in April, 

 May, and June, and again in January. A number of female moths 

 deposited an average of 100 eggs per individual. 



Parasites. — The tachinid Phorocera texana and the braconid Apanteles 

 megathymi were reared from the pupae at San Luis Potosi. 



Olycella subumbrella (Dyar) 



This species has a very extensive distribution in the United States 

 from western Texas to soutliwestern Arizona, thence northward 

 through Utah, Colorado and Kansas to Idaho, Wyoming and Nebras- 

 ka. In Texas its eastern limit is the foothills country between the 

 Devil's and Pecos Rivers and along lat. 30° N. to near Austin, thence 

 north along long. 98° W. to the Oklahoma boundary at Henrietta. 

 Northward it has been located as far as St. Anthony in Idaho. In 

 southwestern Arizona its range extends to the Quijotoa Mountains, 

 the western limit of Platyopuntias. Heinrich lists specimens from 

 California. 



Throughout its range 0. subumbrella is prevalent and is often exceed- 

 ingly common. The list of food plants includes most of the prickly 



