404 U. S. NATIONAL MUSEUM BULLETIN 2 1 6 part s 



Acerastes pertijiax (Cresson) 



FiGUEE 334,d 



Mesostenus pertinax Cresson, 1872, Trans. Amer. Ent. Soc, vol. 4, p. 163; ?• 

 Type: 9, Bosque Co., Tex. (Washington). 



Front wing 4.0 to 5.8 mm. long. 



Head, body, and hind coxa marlced with fulvous, black, and white 

 as in figure 334, d; palpi, front of scape, band on flagellum, a pair of 

 median dashes on mesoscutum, and more or less of median part of 

 hind tarsus, white; antenna black except where described as white; 

 front and middle legs fulvous, their tarsi brown apically, their coxae 

 and trochanters often varied with white or more or less entirely white, 

 especially the front ones; hind trochanters, femur, and tibia fulvous, 

 the apex of tibia of male infuscate; hind basitarsus fuscous in male, 

 fulvous in female, its apex white; second segment of hind tarsus white; 

 third and fourth segments of hind tarsus varying from entirely white 

 to entirely fuscous, the fifth segment always fuscous. 



The black markings on head and thorax are occasionally replaced 

 by piceous or dusky ferruginous, and the black and fulvous 'markings 

 on propodeum are variously blended or replaced by one another. A 

 race in Paraguay and southern Brazil has the hind tarsus more 

 extensively white, with only the basal 0.3 ± of the first segment dark- 

 ened and the last segment and sometimes the apex of the fourth 

 blackish. 



Specimens (15 cf , 519) : From Alabama (Pickett Springs near Mont- 

 gomery) ; Florida (Ililliard, Middle Cape near Cape Sable, and Para- 

 dise Key); Maryland (Takoma Park); North Carolina (Crabtree 

 Meadows in Yancey Co. at 3,600 ft., Hamrick, Highlands, JSIarion, 

 Mount Mitchell at 5,200 ft., and Wake Co.); South Carohna (Green- 

 ville) ; Texas (Brownsville, Hidalgo Co., and Piano) ; Brazil (Nova Teu- 

 tonia in Santa Catarina and near Tijuca at 500 to 1,000 m. in Serras 

 das Orgaos in Rio de Janeu'O Province) ; Canal Zone (Cano Saddle at 

 Gatun Lake and Plantation Borracho); Cuba (Soledad Cienfuegos); 

 Honduras (Prieta); Jamaica (Blue Castle and Hope Farm); Mexico 

 (Minatitlan) ; Paraguay (San Bernardmo); Puerto Rico (Lake Guan- 

 ico); and Venezuela (San Esteban near Puerto Cabello). 



Collection dates in the tropical part of the range show no seasonal 

 pattern, but north of the frost line they are all in late summer or fall. 

 The species has been found in such cool localities as at 5,200 ft. on Mount 

 Mitchell, N.C., but the northern limit of collections is Maryland. 

 These data indicate that it overwinters south of the frost line and 

 works northward every season. The earliest collection dates for the 

 United States are: February 21 and April 2 at Paradise Key, Fla.; 

 March 23 at Brownsville, Tex.; August 6 at Hilliard, Fla.; August 19 



