MEGARHINUS MOCTEZUMA 953 



on outer side; middle tibiifi with dull golden scales on inner side; hind tibiae 

 with scattered golden scales on outer side ; middle tarsi silver marked on outer 

 side of second and basal half of third segment ; hind tarsi with the fourth seg- 

 ment entirely brilliant white. Claw formula, 1.0-1.0-0.0. 



Length : Body 9 to 11 mm. ; wing 7 to 9 mm. 



Genitalia (plate 37, fig. 246) : Side-pieces over twice as long as wide, sharply 

 conically tapered to rounded tips, a low basal lobe bearing four stout setae. 

 Clasp-filament slender, slightly attenuated before middle, bearing a long spine 

 before tip. Harpes long, rather broad, margins revolute, tips bent o\itward, 

 pointed, and with a few minute setae. Harpagones wanting. Unci long, 

 slender, subfilamentous, with bluntly pointed tips. A quadrate basal piece with 

 setae at its corners. 



Larva, Stage IV (plate 128, fig. 444). Head subquadrate, longer than wide, 

 sides nearly straight, insertion of antennae rather prominent; front margin 

 deeply emarginate at middle, produced on each side of it into a large prominent 

 lobe. Antennae cylindrical, slender, rather long, smooth ; two separate hairs at 

 outer fourth, followed by a small tuft ; three minute terminal digits and a seta. 

 Mouth-brushes inserted on frontal lobes, each of ten stout, curved lamellae 

 with cleft tips. Mental plate broadly triangular, with a central tooth in a 

 shallow emargination and nine subequal teeth on each side. Mandible quad- 

 rangular, straight without, smooth ; two branched appendages at angle before 

 tip; an outer row of coarse cilia; terminal dentition of five teeth, very large, 

 ensiform, third and fifth smaller; a large rounded projection basad of the 

 teeth, within which arises a row of long subequal setae. Maxilla rounded 

 quadrangular, basal angle with a group of flattened appendages with recurved 

 tips ; inner angle with shorter filaments, a seta, and two papillae ; palpus nearly 

 separated by the suture, erect, columnar, flat at tip, smooth, with rudimentary 

 terminal digits. Thorax rounded, about as wide as long; lateral hairs short, 

 very stout, mostly singly from large tubercles, the heavy one coarsely spinulose. 

 Abdomen stout, segments angled at sides, anterior ones shorter ; hairs abundant, 

 but not long, all the lateral hairs multiple to fifth segment, double on sixth, 

 inserted on chitinous tubercles. Tracheal tubes broad, enlarged into bladders 

 in the thorax, invisible in the living larva. Air-tube stout, slightly conically 

 tapered outwardly, about three times as long as wide ; no pecten ; a single tuft 

 near base. A large plate on sides of eighth segment with two stout spinulose 

 hairs on its posterior margin. Anal segment about as long as wide, ringed by 

 the plate, fringed behind with a row of spines ; dorsal tufts of two long brushes 

 on each side; a single spinulose lateral hair; ventral brush well developed, of 

 branched tufts with long feathering; anal gills very short, bud-shaped. 



The larvae live in the thick dark brown water in broken and discarded cocoa- 

 nuts, preying upon the larvse of Johlotia, Hcemagogus and other species found 

 therein. Mr. Knab took larvae from cocoanut husks on two occasions. They 

 perhaps also inhabit tree-holes and artificial receptacles, when in favorable 

 situations. Mr. Knab found some adults resting upon low herbage in a wooded 

 place in the daytime. When disturbed they would fly a short distance and 

 alight upon another leaf, usually near the tip. Two of them that were fright- 

 ened away returned to the same bush after a short time and none could be found 

 away from the spot where they were first seen. The specimens were all males. 

 In flying they made a shrill piping sound. Later, in the same place, after rain, 

 two more males were taken upon the same bush and shortly after a female was 

 found on the side of a tree-trunk close by. A thorough search of the vicinity 

 revealed no more specimens. 



Central America. 

 61 



