200 Psyche [December 



NOTES ON THE LIFE-HISTORY OF CORETHRA 

 ALBIPES JOHANNSEN.i 



By C. H. Richardson, Jr. 



Early in August 1912, a number of larvee of Corethra albipes 

 Johannsen together with those of Anopheles punctipennis Say, 

 Ochlerotaius sylvestris Theobald and Ablahesmyia dyari Coquillett 

 were collected in a small pool at Forest Hills, Mass. These were 

 kept in the laboratory for more than a month, observations being 

 made upon them from time to time, with a view to rearing the 

 imagoes, the male of which has not hitherto been described, as 

 well as to gather any facts of interest concerning the biology of 

 this species. 



Corethra albipes was described by Johannsen^ in 1903 from a 

 single female specimen obtained at Ithaca, N. Y., during August 

 1903. Since that time no additional specimens have been men- 

 tioned in literature, and it was therefore with considerable interest 

 that the species was again secured at Forest Hills. 



When full grown the larva of this fly is between 9 and 12 mm. 

 in length, colorless, except for the large black eyes, the black 

 posterior eye-spot, the two pairs of silvery air-sacs, covered dor- 

 sally with large black spots, and the brown-tipped mandibles. 

 Often, too, the digestive tract is conspicuous as a brownish or 

 greenish tube with several enlargements and constrictions. 



In general structure the larva resembles that of Corethra plumi- 

 cornis var. americana Johannsen^ from which it differs in a num- 

 ber of details. There are four long bristles of equal length on the 

 distal end of each antenna as described for americiina, and in 

 addition another short one slightly more than one half as long as 

 the others (see fig. 1). Posteriorly from the antennae, are the 

 filaments of the third metamere of Meinert, five on either side of 

 the median line; back of these the paired transparent appendages 

 of the third metamere of Meinert with serrated outer margins. 



1 Contributions from the Entomological Laboratory of the Bussey Institution, Harvard 

 University, 63. 



2 N. Y. State Museum Bull. 68, 1903, p. 398, pi. 39, fig. 11. 

 » Loc. cit. pp. 395-397, pi. 39, figs. 1-10. 



