Original Description: Insects of Samoa Part VI. Fasc. 2, Nematocera.

59. Chironomus (s. str.) samoensis, sp. n.

m.  f.  Head ochreous, palpi and antennal flagellum rather darker; plumes of m antennae pale.  Frontal tubercles present, of moderate size.  Last segment of m antennae quite three times as long as 2-11 together.  Thorax greenish; scutum with three reddish-orange stripes, the areas between the stripes dusted with silvery-grey. Postnotum not darker than the scutal stripes.  Pronotum slightly emarginate in middle.  Abdomen of m (when not discoloured) green, tergites 2-4 each with a more or less diamond-shaped brown spot near base, 5 brownish, 6-8 darker brown, hypopygium pale.  Seen very obliquely from in from the segments are rather distinctly silvery-grey at the base; seen obliquely from behind the silvery dusting is on the posterior margins of 2-5 and nearly the whoile of 6-7.  Hypopygium with anal point moderately long and slender; claspers slender, not much enlarged at base; upper basal appendage rather small with a downward curved point; the structure almost as figured by Kieffer for Ch. imberbis.  Abdomen of f without distinct markings.  Legs greenish-yellow; tarsi a little darker, first two segments narrowly and rather indistinctly brown at tip.  No darkening on femora, nor on front tibiae.  First segment of front tarsi about 1.8 times as long as tibiae.  No tarsal beard.  Wings hyaline; r-m slightly darkened; venation as in other members of the dorsalis group.  Halteres pale.br/>
Length of body (m) 4.5-5 mm.; wing 3-3.5 mm.
Chironomus samoensis is very closely related to a number of described Australasian species, such as C. subdolus Skuse and C. imberbis Kieff, of the cosmopolitan dorsalis group.  It does not quite agree with specimens of C. subdolus in the British Museum, and is not represented in the collections from the Society Is. and Fiji.  From C. hawaiiensis Grim, it differs chiefly in the absence of dark preapical rings on the femora.

[ Go to C. samoensis | Go to Index ]

Modified: 3 November 2018
Access: Unrestricted
Copyright © 2018, Jon Martin.