Nephrotoma scurra Meigen, 1818

Podeniene, Virginija, Naseviciene, Nijole & Podenas, Sigitas, 2014, Notes on the first instar larvae of Ctenophora and Nephrotoma (Diptera, Tipulidae), Zootaxa 3764 (2), pp. 152-168 : 165-166

Nephrotoma scurra Meigen, 1818

( Figs. 65–72 )

First instar larvae. Length 1.78–1.80 mm; width 0.30–0.31 mm. Body covered with pale pubescence. Cuticle is transparent.

Head capsule. Length 0.39–0.40 mm; width 0.16–0.18 mm. In general it is very similar to that of other Nephrotoma species. Minor differences were noticed in shape of hypostomium, mandible and antenna. Hypostomium bears five sharp teeth and has huge posterior incision ( Fig. 65 ). Mandible in general is very similar to that of other Nephrotoma species, but shapes of teeth are slightly different ( Fig. 66 ). Antenna is very similar to that of N. dorsalis , but shape of basal segment is different ( Fig. 67 ). Labrum in general is very similar to that of N. dorsalis , but arrangement of sensory structures is different ( Fig. 68 ).

Thorax. In general is very similar to that of other Nephrotoma species.

Abdomen. In general is very similar to that of other Nephrotoma species. Setae D1 and D6 are very short; D2 is five times as long as D1; D3 just slightly longer than D2 ( Fig. 69 ); D4 and D5 are similar in length and more than twice as long as D1. Setae D1, D2 and D3, D4 make pairs and are very close to each other. Seta V1 is very short; V2 is five times as long as V1; V3 is three times as long as V1; V4 is twice as long as V1. Setae V1, V2 and V3, V4 make pairs and are very close to each other ( Fig. 70 ). Seta L3 is the shortest; L1 is three times as long as L3; L2 and L4 are similar in length and twice as long as L3 ( Fig. 71 ).

Spiracular disc. Spiracular field is surrounded by four flat, elongate round-tipped lobes ( Fig. 72 ), which bear stripe-shaped sclerites. Lateral lobe is prominent, almost as long as wide at the base and has two long stout apical bristles. The length of each bristle is almost as long as one-fourth of the whole body. Lobe also has two tufts of two short bristles each on dorsal margin. Ventral lobe is almost two-thirds as long as wide at the base. It has an apical tuft of three bristles; four long bristles are situated on inner margin; two short bristles are on outer margin; a tuft of three long bristles is at the base. Three tufts of three long bristles each are placed above the spiracles. Spiracles are large, circular and close to each other. Distance between them is smaller than diameter of a spiracle itself.

Anal field. Anus is surrounded by four short, white and fleshy anal papillae. Anal segment bears a few long setae.

Specimens examined. 17 egg-larvae from female captured near Lazdijai, N54.24084, E23.51580, 23 VI 2011, eggs were laid on 26 VI 2011, egg-larvae hatched on 12 VII 2011; 173 egg-larvae from female captured near Lazdijai, N54.24072, E23.51526, 23 VI 2011, eggs were laid on 24 VI 2011, egg-larvae hatched on 0 8 VII 2011; 86 egg-larvae from female captured in Naujoji Vilnia environs, Vilnius district, N54.70365, E25.405980, 0 9 VIII 2011, eggs were laid on 13 VIII 2011, egg-larvae hatched on 21 VIII 2011; 118 egg-larvae from female captured in Vilnius, N54.68194, E25.27087, 31 VII 2012, eggs were laid on 0 1 VIII 2012, egg-larvae hatched on 0 6 VIII 2012.

Figures

FIGURES 65 – 72. Nephrotoma scurra, first instar larva: 65. Hypostomium. 66. Mandible. 67. Right antenna. 68. General view of labrum. 69. Dorsal abdominal setae (segments II – VII). 70. Ventral abdominal setae (segments II – VII). 71. Lateral abdominal setae (segments II – VII). 72. Spiracular field.