Tipula (Pterelachisus) pseudovariipennis Czizek, 1912

Podeniene, Virginija, Nasevičiene, Nijole & Podenas, Sigitas, 2019, Notes on the first instar larvae of the genus Tipula (Diptera: Tipulidae), Zootaxa 4567 (1), pp. 90-110 : 102-103

Tipula (Pterelachisus) pseudovariipennis Czizek

( Figs. 48–55 )

Examined material: 40 egg-larvae from female captured in Vilnius district, N54.68662, E25.30054, 26 V 2011, eggs were laid on 28 V 2011, egg-larvae hatched on 12 VI 2011; 13 egg-larvae from female captured in Vilnius district, N54.68662, E25.30054, 26 V 2011 , eggs were laid on 28 V 2011, egg-larvae hatched on 16 VI 2011.

First instar larva. Length 1.89–1.92 mm, width 0.44–0.46 mm. Body covered with pale microscopic hairs. Cuticle transparent.

Head capsule. Length 0.36–0.37 mm, width 0.22–0.23 mm. In general, very similar to that of T. (L.) vernalis and other above mentioned species. Differences were noticed in shape of hypostomium, mandible, antenna and arrangement of sensory structures on labrum. Hypostomium bears five sharp long teeth and shape of teeth differ from that of T. (L.) vernalis and other above mentioned species ( Fig. 48 ). Mandible generally very similar to that of T. (L.) vernalis and other above mentioned species, but shape and size of teeth slightly different ( Fig. 49 ). Shape of segment of antenna and size of apical papilla differ from that of T. (L.) vernalis and other above mentioned species ( Fig. 50 ). Labrum in general very similar to that of other known Tipula , but arrangement of setae differ from other above mentioned species: two medium long setae present on membranous part on both sides of labrum ( Fig. 51 ), one medium long and two short setae located on anterior part of labrum, one long and two short setae present on anteriolateral part of labral lobe, one long and one very short setae located on posterior part of labral lobe. Arrangement of setae on frontoclypeus similar to that of T. (P.) irrorata ( Fig. 35 ).

Thorax. Very similar to that of other known Tipula .

Abdomen. In general very similar to that of other known Tipula . Setae D4 and D5 the shortest ( Fig. 52 ). D6 similar in length, but branched into two parts. D1 twice as long as D4 and D5. D2 three times as long as D4 and D5. D3 four times as long as D4 and D5. D2–D3 and D5–D6 very close to each other. V1 absent ( Fig. 53 ), V2 the shortest, V3 and V5 almost three times as long as V2. V4 almost four times as long as V2. V4–V5 make pairs and are very close to each other. L1, L2 very short, L3 and L4 four times as long as L1 and L2. Setae L2 and L3 very close to each other ( Fig. 54 ).

Spiracular disc. Spiracular field surrounded by four almost equal round-tipped lobes, which are flat and elongate ( Fig. 55 ). Lateral lobe 1.5 times as long as width at the base, partly (inner part) covered with dark elongated L-shaped sclerite, lower branch of sclerite extends almost to the center of spiracle. Lobe bears two stout long apical bristles. Each bristle slightly more than five times as long as the lobe. Length of ventral lobe almost as width at the base, inner margin of lobe covered with pale sclerite. Long seta located at the apex of lobe and next to it is a tuft of four medium long setae. Tuft of three short setae and single short setae present on the outer margin of lobe. Tuft of four medium length setae located on outer part of lobe (close to the base). Six tufts of different in length setae located above the each spiracle. The innermost tuft consists of five long setae. Laterally from it two tufts of three short setae, which are close to each other. Laterally from them located tuft of three short setae. Two tufts of two short setae located near the apex of lateral lobe. Spiracles large, circular and close to each other. Distance between them more than diameter of a spiracle.

Anal field. Anus surrounded by four white and fleshy anal papillae. Posterior pair slightly longer than anterior pair. A few medium long setae present on anal segment.

Figures

FIGURES 48–55. Tipula (Pterelachisus) pseudovariipennis, first instar larva. 48: hypostomium; 49: right mandible; 50: right antenna; 51: general view of labrum; 52: dorsal abdominal setae (segments II–VII); 53: ventral abdominal setae (segments II– VII); 54: lateral abdominal setae (segments II–VII); 55: spiracular field.

FIGURES 31–39. Tipula (Pterelachisus) irrorata, first instar larva. 31: hypostomium; 32: right mandible; 33: right antenna; 34: general view of labrum; 35: frontoclypeal setae; 36: dorsal abdominal setae (segments II–VII); 37: ventral abdominal setae (segments II–VII); 38: lateral abdominal setae (segments II–VII); 39: spiracular field.