Colonomyia tasmanica, Jaschhof & Jaschhof, 2008

Jaschhof, Mathias & Jaschhof, Catrin, 2008, The Ohakunea group in Tasmania, with description of Colonomyia tasmanica sp. n. (Diptera: Sciaroidea), Beiträge Zur Entomologie = Contributions to Entomology 58 (2), pp. 441-453 : 445-449

Colonomyia tasmanica sp. n.

( Figs 1-3 , 4A , 5A )

Description:

(for characters not mentioned here see the generic redescription by HIPPA &ZASCHHOF 2004):

Male. Body length: 2.0- 2.2 mm. Head: Postfrons setose. First antennal flagellomere subbasally with up to 4 socketed setae. Fourth flagellomere 5 times as long as wide. Apex of apical flagellomere with a few sensory spines. Setose portion of face small. Labrum non-setose.

Thorax:

Scutum with some sublateral setae larger than others. Microtrichia on postnotum large and clustered in groups of 5-6. Laterotergite non-setose. Legs: Anteroapical depression on fore tibia with numerous setae, the distalmost forming an irregular comb. Mid tibia with apical comb of 6-7 spine-like setae, hind tibia 10-11. Fore basitarsus proximally with no pale setiform sensilla, mid basitarsus with 1, hind basitarsus with 2-3. Wing: Rs traceable as very faint vein close to base of wing, or only by tracheae. M-stem and base of M-fork obliterated. Base of CuA1 very weak, either coalescing at one point with CuA1 and longitudinal vein, or joining longitudinal vein somewhat distal to that juncture. CuA2 sinuous apically, i. e. its apex directed distad. A2 present, albeit short.

Terminalia:

Tergum 9 short, its sclerotized portion consisting of 2 lateral setose lobes connected by narrow asetose portion; basal margin strongly sclerotized ( Fig. 1B ). Gonocoxites with both ventrobasal margin and longitudinal axis strongly sclerotized; ventral emargination wide and long, i. e. extending beyond halflength ( Fig. 1A ). Gonostylus with wide basal portion extended dorsomesally into flat, rounded lobe; distal process bare along full length dorsally and half length ventrally; 3 tiny setulae subapically ( Figs 1 , 2 ). Ejaculatory apodeme spade-shaped in ventral view ( Fig. 1A ). Sperm sac very large, slightly sclerotized ( Fig. 1 ). A tubular extension of sperm sac, the endophallus, present dorsad of ejaculatory apodeme; at transition of sperm sac to endophallus is a large, pubescent membranous bulge ( Fig. 2 ). Each of parameres consist of 2 articulating portions; distal portion with lateral lobe slender and apically serrate, and mesal lobe wide and rounded; proximal portion directed anteroventrad and attached to gonocoxal apodeme ( Figs 1 , 2 ). Sternite 10 subtriangular, densely pubescent and with 2 large setae on distal margin ( Fig. 1B ). Cerci as long as sternite 10, with setae of various sizes ( Fig. 1B ).

Female. Body length: 2.0- 2.5 mm. Head: Vourth antennal flagellomere 4 times as long as wide.

Legs: Fore basitarsus proximally with no pale setiform sensilla, mid basitarsus with 3, and hind basitarsus with 4-5.

Terminalia:

With modification of segments 8 and 9 as follows. Posterior portion of tergum 8 membranous and bare except a pubescent lobe mesally on posterior margin ( Fig. 4A ). Sternum 8 with unsclerotized portion anterior of gonocoxal emargination ( Fig. 3 ), and with interior sclerotized brace laterally ( Fig. 3A ). Surface of tergum 9 bare. Tergite 9 internalized, forming together with gonapophyses moderately sclerotized, complex interior apparatus ( Figs 3A , 4A , 5A ). Gonapophyses largely

separated longitudinally; notum membranous, with cone-shaped sclerotized appendage ( Fig. 5A ). Gonocoxites present as 2 small, pubescent interior lobes ( Fig. 5A ).

Species comparison:

Based on features of the male and female terminalia, Colonomyia tasmanica is the sister species of rakelae . Respective mutual characters are mentioned in the keys above, as well as some of the distinguishing characters.

Distribution and phenology:

The distribution of tasmanica apparently is confined to Tasmania, where its presence is known from four sites distant to one other (see below). At three sites it was found sympatric with albicaulis . Based on the total numbers of specimens found, tasmanica (257) may be regarded as more common than albicaulis (106). Records of tasmanica at Warra are from all months but June and November, with an altitudinal range from 100 to 1100 m a.s.l. Adults were trapped in both unmanaged and treated forest areas, with up to 42 individuals found in a single sample. At Mt Weld three male specimens were found in a pitfall trap at 1100 m a.s.l., which is above the tree line.

Etymology: The species epithet refers to Tasmania, where all specimens known of this species are from.

Types: Holotype: Male, Australia, Tasmania, Warra Long Term Ecological Research ( LTER) Site , Manuka Road (43.07S, 146.67E), in control area, 1 Aug. 2005, by Malaise trap, R. BASHFORD (FT#37051) . Paratypes: 2 females, same site but in pre-logging area, 14 April 2000 (FT#28645); 5 females, same site but in treatment area 1 year post logging, 2 May 2003 (FT#29026); 4 males, 3 females, same site but in treatment area 1 year post logging, 1 July 2005 (FT#36775); 5 males, same data as the holotype ; 1 female, same site but in control area, 2 April 2007 (FT#40220); 2 males, Warra LTER Site , Mt Weld (43.07S, 146.67E), 100 m a.s.l., in mixed forest, 22 Jan. 2002, by Malaise trap, N. DORAN & R. BASHFORD (FT#5833) .

Further material (in ethanol):

Tasmania: 151 males, 75 females, Warra LTER Site, Manuka Road and Mt Weld , 24 March 2000 - 7 Jan. 2008 (52 Malaise and 1 pitfall samples), R. BASHFORD,N. DORAN, M. & C. JASCHHOF ; 1 female, Mersey River 4 km S Liena, 30 Dec. 2007, M. JASCHHOF ; 3 males, 3 females, Lake St. Clair SW shore, 31 Dec. 2007, M. JASCHHOF ; 1 female, Central Plateau, gravelroad from Road B51 to Little Lake (1000 m a.s.l., 41.57.237S, 146.51.928E), 25 Feb.-4 March 2006, N. JÖNSSON, T. MALM & D. WILLIAMS .

Figures

Fig. 1: Colonomyia tasmanica sp. n., paratype males. - A: terminalia, ninth tergite and adjacent structures omitted, ventral view; - B: terminalia, lateral view. 1 = gonocoxite, 2 = gonocoxal apodeme, 3 = gonostylus, 4 = ninth tergite, 5 = paramere, 6 = ejaculatory apodeme, 7 = endophallus, 8 = pubescent bulge, 9 = sperm sac, 10 = tenth sternite, 11 = cercus. Length of scale bar = 0.1 mm.

Fig. 2: Colonomyia tasmanica sp. n., paratype male; terminalia, ninth tergite and adjacent structures omitted, dorsal view. 1 = gonocoxite, 2 = gonocoxal apodeme, 3 = gonostylus, 4 = dorsomesal lobe of gonostylus, 5 = paramere, 6 = ejaculatory apodeme, 7 = endophallus, 8 = primary gonopore, 9 = phallotrema, 10 = pubescent bulge, 11 = sperm sac. Length of scale bar = 0.05 mm.

Fig. 3: Colonomyia tasmanica sp. n., paratype females. - A: terminalia, lateral view; - B: terminalia, ventral view. 1 = eighth tergum, with only the distalmost microtrichia indicated, 2 = pubescent lobe on posterior margin of eighth tergum, 3 = gonocoxite of eighth segment, 4 = desclerotized portion of eighth sternum, 5 = gonapophysis of eighth segment, 6 = labia, 7 = ninth tergum, 8 = gonapophysis of ninth segment, 9 = spermathecal eminence,10 = tenth tergite, 11 = tenth sternite, 12 = proximal cercus segment, 13 = distal cercus segment. Length of scale bar = 0.05 mm.

Fig. 4: Anterior portion of female terminalia, dorsal view. - A: Colonomyia tasmanica sp. n. (paratype); - B: Colonomyia albicaulis COLLESS (specimen from Warra). 1 = eighth tergum, 2 = pubescent lobe(s) on posterior margin of eighth tergum, 3 = ninth tergite, 4 = tenth tergite, 5 = proximal cercus segment. Length of scale bar = 0.05 mm.

Fig. 5: Dorsal wall of female genital chamber, ventral view. - A: Colonomyia tasmanica sp. n. (paratype); - B: Colonomyia albicaulis COLLESS (specimen from Warra). 1 = gonapophysis of ninth segment, 2 = notum, 3 = gonocoxite of ninth segment, 4 = tergite of ninth segment, 5 = spermathecal eminence. Length of scale bar = 0.05 mm.