Full-text - Norsk entomologisk forening

170 T. R. Nielsen
Table 1. A comparison between the sexes of Platycheirus fjellbergi nov. sp., P. ambigztus Fall. and
P. hirtipes Kan.
P. fjellbergi nov. sp. P. ainbiguus Fall. P. hirtipes Kan
8 8 8
Frons not especially broad. Frons broad. Angle at approx- Frons not especially broad.
Angle at approximation of eyes imation of eyes ca. 130°. Fig. Angle at approximation of
100-110'. Fig. 1N. 1 M. eyes ca. llOO.
Third antennal joint norn~ally Third antennal joint brownish- Third antennal joint black,
black, short and roundish; 1.2 black, often with a yellow spot short and roundish; 1.2 times
times as long as broad. Fig. ID. below at base; 1.6 times as as long as broad.
long as broad. Fig. 1H.
Face and frons rather flat, not Face and frons rather flat, Face and frons more protruding,
much protruding. Fig. lA. profile much resembling that of
P. fjellbergi.
face rather 'nosy'. Fig. 10.
Mesonotal pubescence whitish- Mesonotal pubescence whitish- Mesonotal pubescence blackish.
yellow.
yellow.
Front tarsi including the last Front tarsi greyish-yellow, the Front tarsi including last joint
joint black. last joint often yellow. black.
fi black (except tip yellow); fi yellowish, often brownish fi black (except tip yellow);
apical half with strong, black posterolaterally; apical half apical half with black hairs
bristles that decrease in length with strong, black bristles of that are not especially thick.
toward tip of femora. The about same length. The bristles The hairs decrease in thickness
bristles rounded at their tips. rounded at their tips. Fig. 1 J towards their tips. Fig. IP and
Fig. 1F and 1K. fi also with a and 1K. fi also with a long, 1L. fi without any especially
long curled bristle just before curled bristle just before apex. curled bristle at apex.
apex.
ti laterally with only a few ti laterally with only a few ti laterally with a long row of
long, black hairs at thc middle long, yellowish hairs at the isolated black, bristly hairs in
of tibia. Fig. 1G. middle of tibia. practically
tibia.
entire length of
t. with the lateral hairs just ti with the lateral hairs just tr with the lateral hairs just at
at apex short, the hairs black. at apex short, the hairs yellow. apex long. Fig. 1Q.
Fig. IR.
Squaniulae light greyish, post- Squamulae whitish, posterior Squamulae as in P. fjellbergi.
erior rim greyish-brown. rim yellow.
9 Q Q
Antennae black. Third joint Antennae black, third joint with Antennae black. Third joint
short and roundish, 1.4 times a yellow spot below at base. It short and roundish, 1.3 times
as long as deep. is 1.7 times as long as deep. as long as deep.
fi and ft black except for the Ci and fr mainly yellow. 13 fi and fn as in P. fjellbergi.
yellow tip. fs al1 black. broadly yellow at base. fs ycllow at tip.
Squamulae greyish-white with Squamulae purely white. poste- Squamulae with posterior rim
posterior rim darker. rior rim whitish. whitish-yellow.
Tergites black with the spots Tergites black with the spots Tergites shining metallic black.
rather greyish dusted.
glittering metallic bluish.
Rather small species. Medium-sized species. Rather small species.