892 Charles Paul Alexander 



Pentho'ptera alhitarsis 0. S. 



1809 Pcnthoptera albitards O. S. Mon. Dipt. N. Araer., part 4, p. 257-258. 



The larvae of Penthoptera albitarsis are usually not uncommon in rich 



organic mud in shaded places thruout the range of the species. Larvae 



of many sizes, some very small, others apparently almost fully grown, 



may be found at a single time. This would probably indicate that the 



species emerges at intervals thruout the summer, rather than that it is 



double-brooded. 



Larva. — Length, 10-12 mm. 

 Diameter, 1-1.2 mm. 



Colbr bright chestnut-yellow, anterior half of body richer- and deeper-colored; thoracic 

 segments suffused with brown; skin with a silky, iridescent reflection. 



Body provided with numerous long, appressed hairs. A few setae on body, the following 

 being the most conspicuous: one on lateral do. sal margin of last segment, near base of 

 lateral lobes; a series of four groups of one or two in each row across dorsal surface of the 

 three thoracic segments at about midlength; a group of two or three long setae on sides near 

 caudal margin of segments. Subterminal enlargement of abdomen with about twenty-five 

 transverse rows of fine points. 



Bpiracular disk (Plate LVII, 292 and 293) with four blunt lobes; ventral lobes densely 

 fringed with long, pale hairs, those toward ends of lobes longer; one or more elongate setae 

 near tip of each ventral lobe, these being longer than lobes themselves; lateral lobes with 

 a similar fringe of rather short, yellow hairs; spiracular disk almost free from dark mark- 

 ings, a pale brown line extending dorsad from each spiracle and an indistinct brownish line 

 along ventral margin of lateral lobes. Spiracles circular. Anal gills four, pale. Head 

 capsule rather broad, dorsal plate with inner anterior angles rounded. Labrum (Plate 

 LVII, 289) almost as in Eriocera spinosa, the extreme cephalic epipharyngeal parts with the 

 usual papillae and seti'erous tubercles; lateral papillae bearing at their tips three or four 

 slender pegs; between these papillae two pairs of setiferous tubercles, a basal larger pair 

 and a more apical smaller pair. Mandible (Plate LVII, 291) a little more curved than is 

 usual in this subtribe, inner margin with a double tooth at about midlength. 



Pupa. — Length, 10-10.5 mm. 



Width, d.-s., 1.4-1.5 mm. 

 Depth, d.-v., 1.5-1. G mm. 



Thorax dark brown, wing and leg sheaths paler; pronotal breathing horns dark brown, 

 swollen bases and tips much paler, light orange; abdomen brownish yellow. 



Cephalic crest consisting of two widely separated rounded lobes behind, each bearing two 

 setae; anteriorly the crest appearing as a large depressed lobe between antenna! bases, with 

 a very large, stiff seta on either side. A powerful seta on each side of region of clypeus. A 

 seta on genal region between eye and sheath of maxillary palpus. Labrum evenly rounded 

 or a little truncated at apex. Labial lobes widely separated, roughly rounded or indistinctly 

 pentagonal in outline. Maxillary palpi broad, ending bluntly beneath or just before antennal 

 sheaths. Antennae endiag just beyond wing root in female, considerably longer in male. 



