132 
PACIFIC SCIENCE, Vol. V, April, 1951 
Dacus (Hemizeugodacus) algaiae n. sp. 
Fig. 7a-c 
This species very closely resembles Dacus 
(Austrodacus) cucumis (French). It is best 
separated by the subgeneric characters just 
mentioned and by the very faint costal band, 
the median longitudinal vitta down the ab- 
domen, the more elongate antennae, and by 
the differences in the female ovipositor. 
Superficially the species is very similar to D. 
{Zeugodacus) atrisetosus (Perkins), but the lat- 
ter has well- developed anterior supra-alar 
bristles. 
MALE. Entirely pale reddish to yellow ex- 
cept for the black facial spots and the brown 
to black vitta down the abdomen. Head: Front 
comparatively narrow, just two times longer 
than wide. The front is entirely rufous except 
for a faint brownish discoloration in the 
median portion. There are two pairs of in- 
ferior fronto-orbital bristles, the lower pair 
spaced about their length from the oral mar- 
gin. All of the head bristles are pale reddish- 
yellow except for the brownish tinged fronto- 
orbitals. The antennal grooves have a con- 
spicuous row of short yellow hairs extending 
their entire length. The facial spots are sub- 
oval, longer than wide, and conspicuous. 
The third antennal segment is brownish 
tinged, slender, and elongate (for a Dacus); 
it is one and one-third longer than the face 
and its greatest width is equal to slightly less 
than one-fourth its length. Thorax'. With 
three postsutural yellow vittae which extend 
from the suture to a line running between the 
lower pair of post-alar bristles. The median 
vitta is broad, is somewhat narrowed in the 
anterior part, and broadened behind. At its 
widest point it is almost equal to the distance 
between the prescutellar bristles. The lateral 
vittae are narrow, about half as wide as the 
median. The scutellum, humeri, notopleura, 
and the usual pale areas of the pleura are 
clear yellow. The halteres are yellow. The 
bristles of the thorax are yellow-red in color. 
Legs'. Entirely yellow to rufous. The apical 
spurs of the middle tibiae are reddish, the 
length of the spurs is equal to about two 
times the greatest width of the tibiae. Wings'. 
Faintly fumose as seen in reflected light, often 
with broad, faintly yellowish bands along all 
of the veins and crossveins. The costal band 
is faintly brownish and inconspicuous beyond 
the fourth costal section. The band is narrow 
and does not extend below vein R3 except at 
its apex. -The first two sections of the costa 
are yellowish-fumose. The first section is de- 
void of microtrichia except along the top 
margin. The second section is chiefly filled 
with microtrichia. The cubital streak is pale 
brown, fills all of the basal portion of cell M4 
to the base of the m-cu crossvein, but fades 
out before it reaches the wing margin 
(Fig. la). The narrowed portion of the cubi- 
tal cell is slightly less than two times longer 
than the distance from the apex of cell Cu to 
the wing margin. A slight undulation is 
present in the wing margin at the apex of 
vein Cui+lst A, but no distinct lobe is 
present. Abdomen'. With no dark-colored 
crossbands and with the longitudinal median 
vitta extending almost the full length of the 
abdomen fading out on the second tergum. 
The lateral hairs of the third tergum are red- 
dish. 
Length'. Body, 6.2 mm.; wings, 5.9 mm. 
FEMALE. The brownish-yellow cubital streak 
ends about halfway between the apex of cell 
Cu and the wing margin. The narrowed por- 
tion of cell Cu is about equal in length to the 
distance from its apex to the wing margin. 
The abdomen is similar to that of the male 
but lacks the cilia on the third tergum. The 
ovipositor is reddish-yellow, often tinged 
with brown. Ovipositor. The ovipositor is not 
conspicuous in undissected specimens; the 
visible portion is about equal in length to the 
fifth abdominal segment. The entire oviposi- 
tor, about 4.6 mm. in length, is comparatively 
short (Fig. lb). The piercer (Fig. 7c) is 
1.5 mm. long by about 0.3 mm. wide and 
is gradually tapered beyond the apex of the 
oviduct. The tip of the oviduct is about 0.23 
mm. from the apex of the ovipositor. There 
