Nephrotoma crocata Linnaeus, 1758

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 : 159-160

Nephrotoma crocata Linnaeus, 1758

( Figs. 33–40 )

First instar larvae. Length 1.83–1.85 mm; width 0.32–0.33 mm. Body covered with pale pubescence. Cuticle is transparent.

Head capsule. Length 0.40–0.42 mm; width 0.20–0.22 mm. In general, is very similar to that of N. flavescens . Differences were noticed in shape of hypostomium, mandible, antenna and arrangement of sensory structures on labrum. Hypostomium bears five blunt teeth ( Fig. 33 ). Mandible generally is very similar to that of N. flavescens , but shapes of teeth are slightly different ( Fig. 34 ). Segment of antenna is cone-shaped, but membranous apical part is much smaller than in N. flavescens ( Fig. 35 ). There are three small peg-like sensillae on the apex of basal segment. Labrum in general is very similar to that of N. flavescens , but there are two long setae on membranous part of it ( Fig. 36 ).

Thorax. Is very similar to that of N. flavescens .

Abdomen. In general is very similar to that of N. flavescens . Setae D1, D4, D5 and D6 are very short ( Fig. 37 ); D3 is almost twice as long as D1; D2 is very long almost six times as long as D1. Setae D2, D3 and D4, D5 make pairs and are very close to each other. Seta V1 is short; V4 is twice as long as V4 ( Fig. 38 ); V3 is slightly longer than V4; V2 is almost eight times as long as V1. Setae L1, L2 and L3 are close to each other ( Fig. 39 ). Seta L2 is short; L1 is three times as long as L2 and just slightly longer than L3; L4 is situated further from other setae and is approximately as long as L3.

Spiracular disc. Spiracular field is surrounded by four flat and elongate round-tipped lobes ( Fig. 40 ). Lateral pair is more prominent. Lateral lobe is almost as long as wide at the base. It bears four long stout apical bristles. Tuft of two short bristles is located on dorsal part of it and next by it is a single very short bristle. Lobe bears very pale wedge-shape sclerite. Ventral lobe length is nearly half its width at the base. It has a tuft of four bristles at the base. These bristles are different in length. Tuft of two short bristles is on the apical part of lobe and a tuft of three different in length bristles on inner part of lobe. Two short bristles are on the outer margin of lobe. Lobe is almost completely covered with large and very pale sclerites. There are three tufts of long bristles above the spiracles. The outermost tuft consists of two bristles, the others consist of three bristles. Spiracles are large, circular and close to each other. Distance between the spiracles is smaller than diameter of a spiracle itself.

Anal field. Anus is surrounded by four long, cone-shaped, white and fleshy anal papillae. There are a few long setae on anal segment.

Specimens examined. 10 egg-larvae from female captured in Vilnius, N54.68194, E25.27087, 11 VI 2011, eggs were laid on 24 VI 2011, egg-larvae hatched on 22 VI 2011; 16 egg-larvae from female captured near Lazdijai, N54.24096, E23.51549, 23 VI 2011, eggs were laid on 23 VI 2011, egg-larvae hatched on 0 1 VII 2011; 39 egglarvae from female captured near Lazdijai, N54.24060, E23.51560, 23 VI 2011, eggs were laid on 24 VI 2011, egglarvae hatched on 30 VI 2011; 3 egg-larvae from female captured near Lazdijai, N54.24080, E23.51548, 23 VI 2011, eggs were laid on 28 VI 2011, egg-larvae hatched on 0 4 VII 2011; 76 egg-larvae from female captured near Lazdijai, N54.24080, E23.51548, 23 VI 2011, eggs were laid on 23 VI 2011, egg-larvae hatched on 0 1 VII 2011; 67 egg-larvae from female captured near Lazdijai, N54.24095, E23.51552, 23 VI 2011, eggs were laid in 25 VI 2011, egg-larvae hatched on 0 3 VII 2011.

Figures

FIGURES 33 – 40. Nephrotoma crocata, first instar larva: 33. Hypostomium. 34. Mandible. 35. Right antenna. 36. General view of labrum. 37. Dorsal abdominal setae (segments II – VII). 38. Ventral abdominal setae (segments II – VII). 39. Lateral abdominal setae (segments II – VII). 40. Spiracular field.