134 U.S. NATIONAL MUSEUM BULLETIN 256 



Narnia pallidicornis Stal 



The distribution of this species extends from Texas to California and 

 throughout Mexico. The adults are rather variable in the color of the 

 body, elytra, and appendages, and in the degree of the dilation of the 

 hind tibiae. In view of these variations, it is possible that many records 

 of the occurrence of JV. Jemorata and N. inornata in the United States 

 and Mexico refer to pallidicornis. 



In Texas the range of N. pallidicornis extends from Brownsville along 

 the coast to Corpus Christi, and throughout central and western Texas, 

 west from a line drawn from Waco to Abilene. It also occurs over the 

 southern half of New Mexico and Arizona, being abundant in some 

 years in the Tucson district, and is common in southern California from 

 Los Angeles to San Diego. In Mexico it has been taken in the Pacific 

 States at Hermosillo in Sonora and Culiacan and Mazatlan in Sinaloa. 

 It is prevalent in the gulf-coast State of Tamaulipas from the Rio 

 Grande to Tampico and is found, often abundantly, throughout the 

 central plateau from Chihuahua and Coahuila as far south as Tehuacan. 



The host plants include both Platyopuntias and Cylindropuntias 

 (the former much more favored); shrub pears such as 0. lindheimeri, 

 engelmannii, phaeacantha, and occidentalis in the United States; and 

 semitree pears of the 0. streptacantha and O.ficus-indica groups in Mexico. 

 Among the Cylindropuntias our records include 0. leptocaulis at Uvalde, 

 Texas, 0. imbricata, in western Texas and New Mexico, and 0. fulgida 

 and other species in southern Arizona. At Tehuacan, Mexico, adults 

 and nymphs were attacking the fruit of a large Cereus. 



Both adults and larvae prefer the fruit, but they have been observed 

 to feed on younger joints. They appear to cause very little damage. 

 Even where their numbers were concentrated, either in cages or in 

 the field, the fruit ripened normally, and few were destroyed. They 

 favor direct sunlight, and the adults are active insects which fly 

 readily. During the winter months they take shelter among debris 

 near or at the base of the plant and hibernate for a period of 2 to 3 

 months. The eggs are deposited end to end along the spines; more than 

 one row of eggs may be placed on the one spine. The number of eggs 

 deposited by each female is unknown, but fecundity is comparatively 

 high. Thus, from 100 adults placed in cages in June, 4,000 adults and 

 nymphs were obtained in September; assuming that the original 

 number comprised equal proportions of the sexes, the average number 

 of eggs per female would be not less than 80. 



There are two generations annually. The overwintering adults 

 oviposit in March and April, and the first generation reaches maturity 

 in May and June. Eggs of the second generation are deposited from 



