LrTZiA 467 



Lutzia Blanchard, Les Moustlques, 394, 1905. 



Liitsia Dyar & Knab, Journ. N. Y. Ent Soc, xiv, 178, 180, 1906. 



Lutzia Theobald, Gen. Ins., Dipt, Fasc. 26, 15, 24, 1905. 



Lutzia Coquillett, U. S. Dept. Agr., Bur. Ent., Tech. Ser. No. 11, 16, 1906. 



Lutzia Dyar & Knab, Canad. Ent, xxxix, 48, 1907. 



Lutzia Theobald, Men. Cullcld., iv, 151, 1907. 



Lutzia Peryassti, Os Culic. do Brazil, 35, 1908. 



Lutzia Williston, Man. N. A. Dipt, 3 ed., 108, 1908. 



Lutzia Pazos, San. y Ben., ii, 40, 43, 1909. 



Lutzia Theobald, Mon. Culic, v, 116, 1910. 



The type species of Lutzia Theobald is Oulex Mgoti Bellardl. 



Geneeic Diagnosis of Adult: 



Proboscis moderate. Palpi of female rather short, one-third or less the length of 

 proboscis; palpi of male long, acuminate, exceeding proboscis, densely hairy. An- 

 tennae of female slender, with the joints subequal, with basal whorls of sparse deli- 

 cate hairs; of the male densely plumose, the two terminal joints long, the others 

 short and enlarged at insertions of hair whorls. Prothoracic lobes well separated; 

 scutellum trilobate; postnotum nude. Abdomen subcylindrical, truncate at tip in 

 female, long and depressed in male. Legs slender, rather long; empodia of the tarsi 

 large, well-developed; claws of female simple, of male unequal and toothed on front 

 and middle legs. 



Generic Di.4.gnosis of Laeva: 



Head rounded, flattened, broadest posteriorly. Antennas small; mouth parts 

 adapted for predaceous habit; the maxillae quadrangular; the mouth brushes on 

 prominent lobes, of smooth chitinous lamellae, hooked at apices. Air tube long, with 

 a series of tufts and basal pecten. Eighth segment with a lateral comb of many 

 spines. Anal segment ringed by the plate; ventral brush well developed. 



Tropical America, except the West Indies and the arid regions. 



The eggs are cylindrical, similar to those of Oulex, and are laid in boat- 

 shaped masses upon the surface of the water. The larvae are predaceous on 

 mosquito larvse, principally upon those species of Culex that live in ground- 

 pools of semi-permanent water, and in artificial receptacles of large size. 

 Mosquito larvEe apparently constitute their only food. 



Lutzia is developed from Culex, and is closely allied thereto. It is only a 

 Culex developed for a predaceous habit in the larva; the modification of the 

 mouthparts, at first sight so striking, is really of no fundamental significance. 

 The adults axe inseparable from Culex, except by the large empodia, which are 

 evidently only an adaptation to enable this large insect to rest upon the surface of 

 the water. The genus, therefore, is a weak one, scarcely more than a section of 

 Culex. We have concluded to recognize it on the characters mentioned, for what 

 they are worth. The larvse are structurally modified for the preda<;eous habit, 

 the mouth-brushes being inserted upon prominent lobes and transformed into 

 chitinous hooked lamellae; the series of hair-tufts on the breathing-tube how- 

 ever shows the close relationship with Culex. Dr. Lutz first noted the re- 

 semblance of these larvae to those of Psorophora, which is striking, both in gen- 

 eral appearence and in the modifications of the mouthparts. This latter, 

 however, is without value as indicating relationship, since it is but a similar 

 adaptation to similar habits. 



But one species of Lutzia has been described; we here add a second from 

 Panama. We suspect that the specimens from South America will prove 

 specifically distinct from those from our region, but we have no material to de- 

 cide this. Our two forms are very closely related and differ only in details of 

 coloration of the imago. These differences, however, appear to be constant, as 

 we have before us large series of both species and can find no intergrades. 



Tables of the Species. 



ADULTS, STBtrCTtTEE AND COLOKATION. 



1. Wings with three spots of yellow scales on the first vein, fifth vein black-scaled 



near base only allostigma Howard, Dyar & Knab (p. 471) 



Wings with only two spots on first vein, black of fifth vein involving base 



of the fork ligoti Bellardl (p. 468) 



