I 
5-7-1951 — M. A. V. D’Andretta — Contrib. sôbre a família Mydaidac 
71 
Comentários — O material que examinamos, constituído por 
um s e uma $, concorda inteiramente com a diagnose original. 
É uma espécie que facilmente se distingue de todas as outras pela 
cor preta uniforme do corpo. 
ABSTRACT 
The genus Mydas Fabricius, 1794, is inteiisively studied iu this work. Due 
to the variation tliat was found iu many specics of Mydaidac, and to lhe gener- 
ally insufficient diganosis, the Author needed abimdant material for clearing up 
some of the doubts. More than 400 specimens were examined. Some synonyms 
are proposed, new species are described, and a new genus is erected for the 
reception of species difíeriug front the main group hy the extruture of the bucal 
pieces and inale genitalia. 
The principal characters of Mydas, according to the author’s concepts, are 
a long and very protude proboscis, with a developed theca which is as loug as the 
labellnm; a thick and chitinous labellum, more or less triangular in shape and 
with a few pseudotracheae; palpi reduced; apical spur of the posterior tibiae 
present or absent; R5 mcetiug RI apically; Ml ending in the costal vein; the 
transverso vein M4 present or not; aedeagus with developed lateral pieces; eacli 
sclerite of the 9. 9 tergite with a finger-like projection ou its superior border; 
female genitalia without a crown of spines. 
The new genus, natned Mcssitrsia, differs from Mydas, principally by the 
following characters: proboscis short, with an undeveloped theca; the labellum 
is large, membranous, eliptic or circular when its two edges are expanded, and 
with numerous pseudotracheae; the aedeagus generally does not possess.lateral 
pieces, and the 9.'' tergite is triangular in shape, not havind finger-like projection. 
The following key can be used to separate the Neotropical species of Mydas 
examined by the Author : 
1 - Abdômen intirely black, with blue or green met- 
allic reflections. 
- Abdômen orange or dark brown with yellow 
markings. 
2 - Wings almost transparent or slightly darkened 
with brown . ,. 
- Wings very darkened. 
3 - Ilairs of the face wholly white or yellow; abdô¬ 
men parallel-sided; íirst tarsal segment as long 
as the second and third together; squamae with 
a friuge of scales. 
- Hairs of the face wholly black; abdômen clavate; 
first tarsal segment as long as the second; squa- 
mae with a fringe of small bristes .... 
quadrilineatHS Williston 
crassipes Westwood 
cm 1 
; SciELO 
10 11 12 13 14 
