Full-text - Norsk entomologisk forening

128 A. Fjellberg
Fig. 2. A. sefitentrionalis. Dorsal chaetotaxy of
Th. 11-111.
with a distinct tooth at the middle of inner
edge. Empodium sharply pointed, approximately
l/4 of inner length of claw (Fig. 9).
Macrochaeta of thorax and abdomen well
differentiated, pointed. Some of the curved
setae of Abd. V-VI (the segments are fused)
distinctly serrated. Number of setae along
dorsal median line of Th. 11 - Abd. 111 of
adults (variation in parenthesis): 7 (6-9), 6
(4-7), 5 (3-6), 5 (4-6), 5 (6). Th. 11 with 1 + 1
setae along linea ventralis (abnormally one
may be lost or doubled), Th. 111 with 3 - 5
setae at each side of linea ventralis (highly
variable) (Fig. 3). Head with 4 -t 4 setae
along linea ventralis. Ventral tube with 4
caudal and 3 + 3 lateral setae. Ant. IV with
numerous curved sensorial hairs.
Fig. 3. A. atlanticr~s n. sp. Ventral chaetotaxy of
Th. 1 - Abd. 1.
AFFINTTIES
The new species is related to A. sefitentrionazis
Palissa, 1966, but is immediately recognized
by the 1 + 1 ventral setae of Th. 11,
which are not present in A. septentrionalis.
Also the PAO is slightly smaller and more
roundish, the cuticula structure is finer, and
the dorsal clothing of setae is richer (Figs. 1
and 2). A. septentrionalis has never more
than 4 + 4 setae along dorsal median line
of Abd. 1, whereas A. atlanticus usually has
5 + 5. The inner edge of claws is untoothed
in A. septentrionalis. A. atlanticus is a smaller,
more parallel species (Figs. 4 and 5). The
specimens collected in May, which are reproductive
adults, measure 0.7-1.0 mm.
Equivalent specimens of A. sefitentrionalis
measure 0.8-1.3 mm.