Acidiella longipennis

Han, Ho-Yeon, 2011, Acidiella longipennis Hendel, the type species of Acidiella Hendel (Diptera: Tephritidae: Trypetini), with recognition of two new allied species from Myanmar, Zootaxa 2810, pp. 15-25 : 16-18

The Acidiella longipennis species group

Acidiella longipennis Hendel , A. spinipenis , sp. nov., and A. kambaitiensis , sp. nov. ( A. longipennis species group hereafter) look almost identical except for the dorsal abdominal patterns and postabdominal structures. That is why Hering (1938) failed to differentiate them as separate species. Monophyly of the A. longipennis group is supported by a single synapomorphy: vesica of glans ventrally with 7–9 tiny spines ( Figs. 5A–D ). It is a unique characteristic unknown in any other species of the family Tephritidae as well as the related families within the superfamily Tephritoidea. For the tribe Trypetini where the genus Acidiella is currently placed, male genitalic structures of a reasonable number of species have been surveyed ( Han, 1992; Han, 1999). Han (1999) also recognized Acidiella as a member of the Trypeta group within the subtribe Trypetina .

Han (1992, 1999) suggested the monophyly of the genus Acidiella based on a single synapomorphy: posterior surstylar lobe reduced and anterior surtylar lobe expanded and bent inward (as in Figs. 4A–B ). This structure has been repeatedly observed in the majority of species identified under Acidiella but not in most other genera of the Trypetini ( Han, 1999) . Acidiella kambaitiensis , however, do not possess this synapomorphy. I believe that it might have reversed in this species because its close relationship to the other two species of the longipennis group is almost certain as discussed in the above paragraph. This species has an unusually long lateral surstylus ( Fig. 4C ) and this elongation might have caused the reversal. More comprehensive morphological and molecular studies may reveal interesting patterns of character evolution within the genus Acidiella .

Biology of the longipennis group is not known, but they are likely to be leaf miners because almost all the species of the Trypeta group with known host plants are leaf miners except for Flaviludia angustifascia (Hering) and F. echinopanacis Kandybina that are fruit feeders of the family Araliaceae ( Kandybina, 1966; Han, 1998). Within the genus Acidiella , only A. kagoshimensis (Miyake) is known as a leaf miner of Akebia quinata (Houtt.) Decne. of the family Lardizabalaceae ( Ito, 1984) .

Diagnosis. The Acidiella longipennis species group can be distinguished from other known Acidiella species by the combination of the following characteristics: 1) body entirely yellow brown except for dark brown ocellar triangle and dorsal abdominal patterns ( Figs. 1A–C , 3 E–J); 2) wing hyaline with subapical, radial-medial and discal bands broadly joined around crossvein r-m ( Figs. 3A–D ); 3) narrow brown to dark brown band along crossvein DM-Cu; and 4) vesica of glans ventrally with 7–9 tiny spines ( Figs. 5A–D ). Without dissecting male genitalia, similar looking species such as A. disjuncta (Ito) , A. japonica (Hendel) and A. sapporensis (Shiraki) may be readily distinguished by comparing with the characteristic abdominal patterns of the A. longipennis species group ( Figs. 3 E–J).

Description. Body ( Figs. 1A–C ) almost entirely shiny to subshiny yellow brown except for dark brown ocellar tubercle and variable abdominal pattern; setulae and setae mostly dark brown; wing length 4.7–6.2 mm; thorax length 1.6–2.5 mm. Head yellow brown with ocellar tubercle dark brown; with 2 orbital and 3 frontal setae; medial vertical seta 0.6–0.8x longest diameter of eye; lateral vertical seta 0.6–1.0x as long as medial vertical seta; postocellar seta 0.3–0.4x as long as medial vertical seta; paravertical seta shorter than postocellar seta; ocellar seta 1.5– 2.5x as long as ocellar tubercle; scape and pedicel yellow brown with short dark brown setulae; first flagellomere 2.0–2.7x pedicel length, apically rounded; arista entirely short pubescent, yellow brown; facial carina shallow with rounded margins; parafacial less than 0.3x as wide as first flagellomere; facial ridge with fine dark brown setulae; genal seta strong; postgena moderately swollen with relatively long dark brown to yellow brown setulae; postocular setae extended 0.6–0.8x distance from upper eye margin to lower eye margin; supracervical setae yellow brown; mouthparts short with labella yellow brown setulose and palpi dark brown setulose. Thorax almost entirely yellow brown with dark brown setae and setulae; postpronotal lobe slightly paler than scutum; scutum subshiny yellow brown with short fine dark brown setulae; 1 postpronotal, 2 scapular, 1 acrostichal, 1 dorsocentral, 1 intra-alar, 1 presutural supra-alar, 1 postsutural supra-alar, 1 postalar and 2 notopleural setae; dorsocentral seta about half to 0.7x distance from level of postsutural supra-alar seta to intra-alar seta; scutellum slightly convex with sparse fine dark brown marginal setulae; basal scutellar setae divergent and apical setae more or less parallel; proepisternum densely covered with long brown setulae; anepisternum yellow brown with upper area whitish yellow, with single strong seta and 1 slightly shorter seta ventral to it; mediotergite shiny yellow brown. Legs entirely yellow brown with dark brown setae and setulae; fore femora with 4–6 posteroventral setae. Wing hyaline with yellow brown to dark brown pattern: anterior half almost brown to dark brown except entirely hyaline cells bc and c, and two large, hyaline inverted triangles in cells r1 and r2+3 immediately distad of pterostigma; cell br subapically with small round hyaline spot touching vein M; cell r4+5 with semicircular hyaline spot immediately distad of crossvein DM-Cu; cell bm yellow brown; cell dm with brown band subapically; cell cu2 with short brown to yellow brown area connected to band in cell dm; crossvein DM-Cu with narrow brown band; R4+5 dorsally with 7–11 tiny setulae between node and R-M, no setula apical to R-M; posteroapical extension of cell bcu about as long as crossvein BM-Cu.

Male abdomen slightly longer than wide, yellow brown in ground color with dark brown setae and setulae; T3- 5 with interspecifically variable dark brown pattern; epandrium with tiny setulae and long dark brown setae; posterior surstylar lobe reduced and anterior surstylar lobe expanded and bent inward in longipennis and spinipenis ( Figs. 4A–B ); in kambaitiensis , posterior surstylar lobe small but not reduced and anterior surstylar lobe not expanded ( Fig. 4C ); proctiger pale yellow with brown to dark brown setae; medial surstylus with lateral prensiseta about half as long as medial prensiseta; medial sclerite of glans well defined with internal pattern of fine granulation, granules relatively small, spaced approximately by diameter of each granule; dorsal sclerite of glans extensively with internal sculpture pattern of elongated cells; vesica of glans ventrally with 7–9 tiny spines; ejaculatory apodeme broad, fan-shaped.

Female abdomen (not available for spinipenis ) yellow brown ground color with interspecifically variable dark brown pattern on T3-6; oviscape entirely shiny dark brown; eversible membrane with taeniae 2/5–1/2 as long as total length of membrane, ventrally on basal half with spinules moderately well differentiated; aculeus broad, more or less parallel-sided with apical 2/5–1/2 tapered with serration; 2 brown spermathecae with transverse spinular papillae; apical portion of spermathecal duct swollen.

Figures

FIGURE 5. A – D. Glans (inset at 8 x main figure). A. Acidiella longipennis, holotype. B. A. longipennis, Myanmar specimen; C. A. spinipenis, sp. nov., holotype. D. A. kambaitiensis, sp. nov., holotype. E. Ejeculatory apodeme of A. longipennis, Myanmar male.

FIGURE 4. A – C. Lateral and caudal view of epandrial complex. A. Acidiella longipennis, holotype. B. A. spinipenis, sp. nov., holotype. C. A. kambaitiensis, sp. nov., holotype.

FIGURE 1. A – C. Myanmar specimens in lateral and dorsal views. A. Acidiella longipennis, male. B. A. spinipenis, sp. nov., male. C. A. kambaitiensis, sp. nov., male.

FIGURE 3. A – D. Wings. A. Acidiella longipennis, holotype male. B. A. longipennis, Myanmar male; C. A. spinipenis, sp. nov., holotype male. D. A. kambaitiensis, sp. nov., holotype male. E – J. Abdomens. E. A. longipennis, holotype male. F. A. longipennis, Myanmar male; G. A. longipennis, Myanmar female. H. A. spinipenis, sp. nov., holotype male. I. A. kambaitiensis, sp. nov., female. J. A. kambaitiensis, sp. nov., holotype male.