Plecia membranifera Hardy & Takahashi, 1960

Sutou, Mitsuaki, 2006, Immature stages of three Japanese species of the genus Plecia Wiedemann (Diptera: Bibionidae), Zootaxa 1223, pp. 1-18 : 8-9

publication ID

https://doi.org/ 10.5281/zenodo.172619

DOI

https://doi.org/10.5281/zenodo.6260293

persistent identifier

https://treatment.plazi.org/id/03C887CB-2D6A-FFE7-5A03-10D9FC3EDB8F

treatment provided by

Plazi

scientific name

Plecia membranifera Hardy & Takahashi, 1960
status

 

Plecia membranifera Hardy & Takahashi, 1960 View in CoL

Description

Egg: Shiny brown, with slightly rough surface ( Fig. 3 View FIGURE 3 A) observed at high magnification (×200–400), 0.58–0.67 mm long (n = 20).

First­instar larva: Head ( Fig. 3 View FIGURE 3 C), yellowish brown; genae with 6 setae anteriorly, 2 sensory pits and 6 minute setae along posterior stem of ecdysial suture ( Fig. 3 View FIGURE 3 C: 4–7), these minute setae sometimes disappear depending on condition of specimen; frontal apotome with 2 long and 2 short setae ( Fig. 3 View FIGURE 3 C: 1–2); clypeus with 4 setae and 6 sensory pits dorsally, lateral projection of clypeus with short setae apically; labrum with 2 papillae and conical processes anteriorly; antennal plate relatively large in comparison to that of final­instar larva; mandible with 3 setae on basal half. Body ( Fig. 3 View FIGURE 3 B) creamy white without processes, body segmentation of thorax indistinct, weakly arched in shape; brownish gut contents visible through translucent cuticle; only 1 pair of spiracles located posteriorly. Width of head capsule 0.20–0.23 mm (mean ± SD = 0.21 ± 0.01 mm, n = 20); Body length 1.0– 1.3 mm (mean ± SD = 1.2 ± 0.1 mm, n = 28).

Final­instar larva: Genae with 6 setae anteriorly, 2 minute setae and 14 sensory pits dorsally including 4 pairs along posterior stem of ecdysial suture ( Fig. 3 View FIGURE 3 G: 4–7); genae and frontal apotome with some spotted maculae; frontal apotome with 2 setae and 4 sensory pits ( Fig. 3 View FIGURE 3 G: 1–3). Clypeus with 4 setae and 6 sensory pits dorsally ( Fig. 3 View FIGURE 3 G). Labrum with 2 small papillae dorsally, about 10 small papillae and fine setae on its anterior membranous part ( Fig. 3 View FIGURE 3 G). Epipharynx ( Fig. 3 View FIGURE 3 H) with many fine setae, small conical processes, 2 rows of denticles, 8 differentiated small papillae and 4 sensory pits. Mandible ( Figs. 3 View FIGURE 3 I, J) with 3 blunt teeth (teeth may be rather worn by feeding activity), welldeveloped prostheca attached inside, 3 setae and 2 dorsal sensory pits on its basal half.

Cardo with 3 setae and sensory pit ventrally ( Fig. 3 View FIGURE 3 M). Galeolacinia nearly trapezoidal in shape, with conical projection anteriorly ( Figs. 3 View FIGURE 3 L, M); dorsal surface with fine setae, spinules, minute papilla, and 6–7 sensory pits ( Fig. 3 View FIGURE 3 L); ventral surface with 2 setae and row of denticles anteriorly ( Fig. 3 View FIGURE 3 M). Stipes composed of 3 parts: proximal isolated appendage, middle sclerite bearing seta and sensory pit with dorsal U­shaped invagination, and distal membranous ring with sensory pit and some spinules ( Figs. 3 View FIGURE 3 L, M). Maxillary palpus with sensory pit and 10–12 apical papillae, one of which is slightly larger than others ( Fig. 3 View FIGURE 3 M). Central membranous area of labium with 10–14 small papillae and fine setae on its anterior margin ( Fig. 3 View FIGURE 3 K). Hypopharynx nearly elliptical in shape with some pubescence ( Fig. 3 View FIGURE 3 K). Body brown, arrangement of processes as shown in Table 1 a. Platelike ventral swelling of prothorax ( Fig. 3 View FIGURE 3 E) with 2 conical processes. Body cuticle covered with many spinules ( Fig. 3 View FIGURE 3 F). Width of head capsule 0.74–0.88 mm (mean ± SD = 0.81 ± 0.05 mm, n = 9); Body length 12.8–17.1 mm (mean ± SD = 15.1 ± 1.4 mm, n = 15).

Pupa. Male ( Figs. 4 View FIGURE 4 A, B): Vertex semicircular in frontal view; antenna slightly arched, lying transversely; maxillary palpus attenuated apically and extending transversely; rostrum short. Prothoracic spiracle vestigial. Extremities of hind legs reaching posterior part of 2nd abdominal segment. Arrangement of body processes as shown in Table 1 b, but dorsum of A2 and A7 each with only 2 setae in some specimens. Abdominal spiracles slightly protruded from body surface. Body length 6.9–8.5 mm (mean ± SD = 7.6 ± 0.4 mm, n = 13). Female ( Fig. 4 View FIGURE 4 C): similar to male, but compound eye smaller, abdomen thicker than that of male. Body length 7.9–8.6 mm (mean ± SD = 8.4 ± 0.3 mm, n = 5).

Specimens examined

Egg: Laid by females reared from larvae collected on 19.III. 2001 in Korimoto, 31°34’N 130°32’E, 30 m alt., Kagoshima, Kagoshima Pref. First­instar larva: 28 examples (5 examples in NSMT), late May 2001, hatched from above eggs. Final­instar larva: 16 examples (3 examples in NSMT), 19.III.2001, same locality. Pupa: 13♂, 6Ψ (3♂, 2Ψ in NSMT), reared from larvae collected on 19.III. 2001 in same locality.

Ecological notes

This is a rare species, evidenced by the fact that this is only the second record of this species since its original description. Its distribution appears to be restricted to Kagoshima Prefecture, the southernmost part of Kyushu Island. The gregarious larvae of this species, consisting of 103 individuals, were collected in March from soils in open habitat where the herb Hedera rhombea was dominant. Afterward, the reared adults emerged in mid­April. Adult males flying over a lawn near the site were collected in August 1999. Therefore, this species most likely produces two or three generations per year.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Bibionidae

Genus

Plecia

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