1966] 
Evans — Neotropical Potnpilidae 
119 
parapenial lobes shorter than aedoeagus and digiti (Fig. 1) .... 
I. bergi (Holmberg) 
Abdomen almost wholly rufous, the subgenital plate contrastingly 
black; clypeus and scape with rather dense, black setae; inner 
orbits subparallel, upper interocular distance 1. 00 1.05 times 
lower interocular; parapenial lobes large, slightly exceeding 
aedoeagus and digiti (Fig. 2) 2. jaffueli (Herbst) 
1. Aridestus bergi (Holmberg) 
Vompilus bergii Holmberg, 1881, Anales Soc. Cient. Argentina, 12: 142- 
[Type: $, Argentina: Prov. Buenos Aires (C. Berg) (Mus. Arg. Cienc. 
. Nat.)]. 
Aridestus bergi Banks, 1947, Bull. Mus. Comp. Zool. Harvard, 99: 432. 
Female . — -Length 5. 7-9.0 mm; fore wing 5.0-7.0 mm. Head and 
thorax black, the pubescence silvery at least on the clypeus, lower 
front, anterior and posterior parts of the pronotum, parts of the 
pleura and leg-bases, and posterior slope of the propodeum, often 
almost wholly silvery-sericeous, the band along the pronotal margin 
especially heavy; abdomen rufous except black at extreme base, apex 
sometimes weakly infuscated, wholly covered with fine, pale pubes- 
cence; wings subhyaline or lightly infuscated, with a broad darker 
band along the outer margin of the fore wing. Temples and pro- 
pleura with some erect hairs, body otherwise barely hairy except for 
dark hairs on the clypeus, front, vertex, and scape in occasional 
specimens. Clypeus 2. 1-2.4 times as wide as high, truncate or slightly 
concave apically. Front narrow, middle interocular distance .52-. 58 
times transfacial distance; upper interocular distance .95-1.00 times 
lower interocular; POL subequal to or slightly exceeding OOL. 
Third antennal segment 2. 8-3. 5 times as long as thick, equal to .50- 
.63 times upper interocular distance. Posterior slope of propodeum 
with transverse rugae, but the rugae not nearly reaching the extreme 
lateral margins. Front basitarsus with three comb-spines, the basal 
one usually shorter than the others. Third submarginal cell tri- 
angular or subtriangular. 
Male. — Length 5. 5-6.0 mm; fore wing 4.8-5. 1 mm. Head and 
thorax black except posterior margin of pronotum with a pale band; 
abdomen rufous except extreme base black, fifth and sixth segments 
fuscous, apical tergite whitish; body very extensively clothed with 
silvery pubescence, the pubescence dark on the vertex, most of the 
mesoscutum and scutellar disc, and base of the fifth abdominal seg- 
ment; wings hyaline, with a broad brownish band along the outer 
margin of the fore wing. Temples and propleura with abundant 
pale hairs; scape, front, and vertex with short, dark setae. Clypeus 
