Chalarus argenteus Coe, 1966

Kehlmaier, Christian & Assmann, Thorsten, 2008, The European species of Chalarus Walker, 1834 revisited (Diptera: Pipunculidae), Zootaxa 1936, pp. 1-39 : 18

Chalarus argenteus Coe, 1966

Chalarus argenteus Coe, 1966: 156 .

Diagnosis: Male unknown. Female with frontal facets moderately enlarged (J92 Fig. 2 A); frons at narrowest point 1.2–1.5 times diameter of largest frontal facet; flagellum dark brown; legs entirely dark brown; pulvilli of all legs of same size, shorter than distitarsus; hairs on femora light to mid brown in holo- and paratype; hairs on thorax and abdomen mid to dark brown; posterior/posterodorsal hair fringe on mid femora ( Fig. 79 ); hind femur with apical hairs of pdsr extending as far as apex; abdominal tergites dark brown; ovipositor as in Figs 65–66 . No DNA barcode could be obtained.

Annotations: The holotype and the paratype of C. argenteus were obtained for study, as was the only reared specimen (ex. Typhlocyba quercus ) mentioned in Jervis (1992). The abdomen of the holotype was removed in order to enable a detailed study of the shape of the ovipositor ( Fig. 66 ). Unfortunately, the ovipositor suffered deformation in this process but its shape is still discernible. In the past, the ovipositor of the paratype was dissected and placed in canada balsam. Today, the embedding medium is partly chipped off and the ovipositor lost. Based on adult morphology, C. argenteus strongly resembles C. spurius but normally has a slightly shorter and straighter tergite 9 (ovipositor’s piercer), a slightly narrower frons and a slightly longer, paler and more strongly curved posterior/posterodorsal hair fringe on mid femora (compare Figs 79–80 ). Jervis (1992 & in litt.) provides convincing larval/pupal evidence for an independence of the taxon by comparing the shape of the mandibles of second instar larva of C. argenteus and C. spurius (J92 Figs 38 E & Q–R) and the posterior spiracular plate of fully grown larva/puparium (J92 Figs 40 B & 42E). Both features clearly differ from each other — note that the upper margin of the posterior spiracular plate of C. argenteus is partly covered with debris and hence not clearly visible.

Figures

FIGURES 1 – 6. Inner male genitalia (phallus). 1. C. fimbriatus agg.; 2. C. absconditus spec. nov.; 3. C. clarus; 4. C. immanis spec. nov.; 5. C. juliae; Abbreviations: lower ej. d., lower ejaculatory ductuli; mtdp, membranous tip of distiphallus; php, phallic processes; phs, phallic shaft; tdp, tip of distiphallus; upper ej. d., upper ejaculatory duct; 6. C. latifrons. Scale bars = 0.1 mm.

FIGURES 79 – 80. Right mid femur in posterodorsal view with posterior / posterodorsal setal row (other hairs omitted) of female. 79. C. argenteus; 80. C. spurius. Scale bars = 0.1 mm.

FIGURES 63 – 75. Female ovipositor. 63 – 64. C. spurius lateral view; 65 – 66. C. argenteus lateral view; 67. C. spurius dorsal view; 68. C. marki spec. nov. dorsal view; 69. C. marki spec. nov. lateral view; 70. C. decorus lateral view; 71. C. indistinctus lateral view; 72. C. longicaudis lateral view; 73. C. brevicaudis lateral view; 74. C. indistinctus dorsal view; 75. C. brevicaudis dorsal view. Scale bars = 0.1 mm.

FIGURES 34 – 48. Female ovipositor. 34. C. pughi ventral view; 35. C. basalis ventral view; Abbreviation: s 7, sternite 7; 36. C. pughi dorsal view; Abbreviations: t 7, tergite 7; t 8, tergite 8; t 9, tergite 9; 37. C. basalis dorsal view; 38. C. pughi lateral view; 39. C. basalis lateral view; 40. C. fimbriatus lateral view; 41. C. fimbriatus Form A lateral view; 42. C. fimbriatus Form B lateral view; 43. C. juliae dorsal view; 44. C. leticiae dorsal view; 45. C. juliae lateral view; 46. C. leticiae lateral view; 47. C. elegantulus lateral view; 48. C. latifrons lateral view. Scale bars = 0.1 mm.