WYEOMYIA GUATEMALA 75 



tufts. Tracheal tubes moderately broad, band-shaped, strongly flexuous, nar- 

 rowed in seventh and eighth segments. Air-tube slender, slightly tapered on 

 outer two-fifths, with single scattered hairs ; a black ring at base. Lateral comb 

 of eighth segment a rather long band of spines, single above but widening to 

 two or three deep below, the lower ones smaller; single spine thom-shaped, 

 pointed from the side view, broad, with seven terminal spinules from the top 

 view. Anal segment as long as wide, with a dorsal plate completely cut at 

 comers and edged by a black rim; dorsal tuft of two groups of long hairs on 

 each side; two long lateral hairs at angle of the plate; a pair of small sub ventral 

 tufts. Anal gills moderate, broad, twice as long as the segment, with rounded 

 tips and fine tracheae, all four equal. 



The larvae live in water in dead vegetable tissues, such as tree-stumps, cocoa- 

 nut-shells and cacao-husks, containing much vegetable detritus and rich in 

 organic matter. Mr. Busck observes : 



" The larvae are long, slender, and monilif orm, with yellow head, short tube, 

 and long anal appendages ; they hang perpendicularly from the surface of the 

 water when breathing, but can remain very long under water and burrow down 

 into the sediment on the bottom when disturbed; they are thus easily over- 

 looked." 



Central America and Panama. 



Sonsonate, Salvador, larvse from water in cocoanut-husks, August 30, 1905 

 (F. Knab) ; Zent, 30 miles inland from Port Limon, Costa Eica, larvae in very 

 dark-brown liquid in the hollow stump of a banana tree, September 16, 1905, 

 associated with Oulex mortificator (F. Knab) ; Port Limon, Costa Eica, larvae 

 in cacao-husks in cacao orchard, September 38, 1905, associated with Limatus 

 cacophrades (F. Knab) ; Gatun, Canal Zone, Panama, larvs in a hollow tree- 

 stump, June 10, 1907, associated with Hwmagogus albomaculatus (A. Busck) ; 

 Caldera Island, Panama, larvae in a hollow in the stump of a banana tree, May, 

 39, 1908 (A. H. Jennings) ; Tabernilla, Canal Zone, Panama, larvae in bamboo- 

 traps, December 15, 1908 (A. H. Jennings) ; Las Cascadas, Canal Zone, Pan- 

 ama, May 17, 1908, larvae in a tree-hole (E. L. Turner). 



The specimens are all bred and have been killed too soon after emergence, so 

 that the eyes and other parts of the head are much shrunken and invaginated. 

 As a consequence we are unable to see the exact condition of the strip of integu- 

 ment between the eyes. It is evidently very narrow, the eyes seeming practically 

 contiguous above. We assume that the strip widens somewhat below, although 

 this part is concealed in all the specimens. The species seems closely allied to 

 the preceding species (W. agnostips D. & K.), having similar coloration and 

 structure of the wing-veins, so that it seems probable that the head structure is 

 also similar. Later specimens show a very narrow strip between the eyes, widen- 

 ing to a wedge below. 



WYEOMYIA GUATEMALA Dyar & Knab. 



Wyeomyia guatemala Dyar & Knab, Proc. Biol. Sec. Wash., xix, 139, 1906. 

 Wyeomyia ailechra Dyar & Knab, Proc. U. S. Nat. Mus., xxxv, 66, 1908. 

 Wyeomyia guatemala Theobald, Men. Cullc, v, 624, 1910. 

 Wyeomyia ablechra Theobald, Men. Culic, v, 626, 1910. 



Obiqinai, DESCKipnoN or Wyeomyia Guatemala: 



Prothoraclc lobes silvery white; head black on the occiput, a very narrow white 

 margin to the eyes, distinct at vertex and sides, nearly obsolete at the middle. Body 

 and legs colored as in the other species of this group. 



Two specimens, Trece Aguas, Alta Vera Paz, Guatemala, April (Schwarz and 

 Barber) . 



Type.— Cat. No. 9994, U. S. Nat. Mus. 



