Nephrotoma submaculosa Edwards, 1928

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 : 164-165

Nephrotoma submaculosa Edwards, 1928

( Figs. 57–64 )

First instar larvae. Length 1.59–1.60 mm; width 0.31–0.32 mm. Body is covered by pale pubescence. Cuticle is transparent.

Head capsule. Length 0.37–0.38 mm, width 0.18–0.20 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. Three middle teeth are very similar is size and shape; the outermost teeth are much smaller. There is a prominent incision on posterior part of hypostomium ( Fig. 57 ). Mandible in general is very similar to that of N. flavescens , but shapes of teeth are slightly different ( Fig. 58 ). Antenna is very similar to that of N. dorsalis , but shape of basal segment is different ( Fig. 59 ). Labrum in general is very similar to that of N. dorsalis , but arrangement of sensory structures is different ( Fig. 60 ).

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

Abdomen. In general is very similar to that of other Nephrotoma species. Seta D1 is very short; D2 is long and four times as long as D1 ( Fig. 61 ); D3 is slightly shorter than D2; D4 and D5 are very similar in length and slightly longer than D1; D6 is the shortest seta and twice as short as D1. Setae D2, D3 and D4, D5 make pairs and are very close to each other. Seta V1 is long; V2 is slightly longer than V1 and is the longest ventral seta ( Fig. 62 ). Setae V3 and V4 are very similar in length and half the length of V1; V1, V2 and V3, V4 make pairs and are very close to each other. Lateral setae are arranged in a line. Setae L1, L4 are very similar in length and three times as long as L2 ( Fig. 63 ). Seta L3 is twice as long as L2; L4 is situated away from the other setae.

Spiracular disc. Spiracular field is surrounded by four almost equal, flat, elongate and round-tipped lobes ( Fig. 64 ). Lobes are almost as long as their width at the base. Lateral lobe has two long stout apical bristles. Each bristle is almost as long as one-third of the whole body. Base of the inner bristle extends into an irregular stripe-shaped sclerite, which ends above the spiracle. A tuft of two long bristles and a tuft of three long bristles are situated above that sclerite on dorsal part of the lobe. Above the spiracles there are three tufts, each consisting of three bristles of different length. Ventral lobe has an apical tuft of four long bristles; three bristles, similar in length, are situated on inner margin; a tuft of three short bristles is on outer margin; a tuft of two short bristles close to it; a tuft of four long bristles is at the base. The lobe bears very pale oval-shaped sclerite. Spiracles are large, oval and close to each other. Distance between them is the same as diameter of a spiracle itself.

Anal field. Anus is surrounded by four short, white and fleshy anal papillae. Few long setae are on anal segment.

Specimens examined. 15 egg-larvae from female captured near Lazdijai, N54.24096, E23.51549, 23 VI 2011, eggs were laid on 25 VI 2011, egg-larvae hatched on 0 2 VII 2011.

Figures

FIGURES 57 – 64. Nephrotoma submaculosa, first instar larva: 57. Hypostomium. 58. Mandible. 59. Right antenna. 60. General view of labrum. 61. Dorsal abdominal setae (segments II – VII). 62. Ventral abdominal setae (segments II – VII). 63. Lateral abdominal setae (segments II – VII). 64. Spiracular field.