Disparomitus bacillus ( Gerstaecker, 1885 )

Michel, Bruno, 2019, Revision of the genus Disparomitus van der Weele, 1909 with descriptions of four new species (Neuroptera, Ascalaphidae), Zootaxa 4551 (1), pp. 1-39 : 6-9

Disparomitus bacillus ( Gerstaecker, 1885)

( Figs 9–16 , 85 , 99–102 )

Suphalasca bacillus Gerstaecker, 1885: 5 (subsequent spelling of Suhpalacsa Lefèbvre, 1842 ).

Suphalacsa subcostalis Navás, 1912: 405 , (subsequent spelling of Suhpalacsa Lefèbvre, 1842 ), plate XXI fig. 3, n. syn. Disparomitus bacillus ( Gerstaecker, 1885) : van der Weele 1909: 192, figs 139–142.

The name Encyoposis bacillus ( Gerstaecker, 1885) written on the card associated with the specimen in EMAU is an unpublished and erroneous combination ( Fig. 9 ).

Diagnosis. Wing length (mm): ♂ forewing 30–35, hind wing 25–29; ♀ forewing 36–37, hind wing 29–30.

Male. General colouration brown with slightly contrasted darker markings ( Fig. 9 ). Mesoscutellum with two lateral black markings and a posterior horizontal brown line interrupted in the middle ( Fig. 14 , 85 ). This line is rounded and not tapered at the extremities. Area between subcostal and radial veins suffused with brown. Dorsal setae on abdominal tergite I stout, those on abdominal tergite II are thinner and longer ( Figs 12, 13 ). Lateral spines on tergites II and III minute ( Fig. 12 ). Female ( Fig. 16 ). Yellowish brown, lighter in colour than male.

Redescription. Male. Head. Face and vertex light brown. Thorax ( Figs 9–11, 14 , 85 ). Pronotum brown, darker on the disc. Mesonotum: prescutum dark brown. Scutum dark brown dorsally, bordered with pale brown, this pale area is wider posteriorly. Scutellum brown dorsally with two black lateral markings. Posterior area with transverse dark line under the black markings. This line is not tapered laterally and can be lighter in colour; it is generally interrupted in the middle. Metanotum: scutellum paler posteriorly with black erect stout setae. Side of thorax ( Fig. 11 ) brown with anepisternum, basisternum and katepisternum of mesothorax slightly darker.

Forewing. All veins brown. Membrane hyaline, suffused with brown in some specimens. Area between subcostal and radial veins and sometimes between costal and subcostal veins suffused with light brown. Legs ( Figs 10, 11 ). Light brown, almost concolourous. Abdomen ( Figs 10–13 ). Tergites brown, slightly paler dorsally with a thin brownish longitudinal line. Dorsal setae on tergite I long, same as on metathoracic scutellum ( Fig. 12, 13 ). Second tergite with a tuft of long setae, distinctly thinner than those of the first tergite ( Fig. 13 ). Sides of second and third tergite with minute spines (distinctly thinner and smaller than those of D. abyssinicus ). The area covered with spines ends at 2/3 of tergite III. Sternite I to III yellowish with a large longitudinal black line; this line is distinctly narrowed anteriorly and forked posteriorly on sternite III ( Fig. 10 ). This line is more or less distinctly delimited on the following abdominal sternites. Male ectoprocts with a dorsal brown marking. Male genitalia. Gonarcusparameres complex as in figures 99–102. Gonarcus slightly extended above the parameres. Parameres short, ovoid seen from behind. Female ( Fig. 16 ). Same colouration as male but sometimes paler and more yellowish. The black markings of the abdomen are more contrasted compared to the lighter yellowish integument.

Material examined (16 ♂♂, 12 ♀♀). In the original description, Gerstaecker did not indicate the number of specimens he examined but according to van der Weele (1909), he described the species from four males and one female collected at Abo in Cameroon, without designating a holotype. Those specimens constitute the type series and must be considered as syntypes. They are deposited in two museums, EMAU and NHMUK. In 1968, Tjeder labelled two ♂ syntypes as lectotype ( Fig. 9 ) and paralectotype, respectively ( Fig. 15 ), but he did not publish the designations that are therefore unavailable. However, I retain Tjeder's designations of the same two specimens as lectotype and paralectotype respectively. Lectotype ♂ (designated here) of Suphalasca bacillus Gerstaecker , CAMEROON, Abo , 4.0522820/9.7679920, alt. 24 m, ii-iii.1874, Buchholz leg. (II27513a EMAU) ( Fig. 9 ) . Paralectotype ♂ (designated here) of Suphalasca bacillus Gerstaecker , CAMEROON, same locality as lectotype, coll. Van der Weele leg. (1907 N°6, RMNH) ( Fig. 15 ) . Holotype ♀ of Suphalacsa subcostalis Navás, 1912 DEMOCRATIC REPUBLIC OF CONGO, Dima , - 3.274574/17.483215, alt. 299 m, 23.ix.1908, A. Koller leg. (R. DÉT. D. 226, MRAC) ( Fig. 16 ) . Additional material. CAMEROON: 2 ♂♂ no collection locality, Suphalasca bacillus det. Banks (R-48, NHMUK) . 1 ♀ no collection locality, Suphalasca bacillus det. Banks, McLachlan coll. (R-63, NHMUK 1938–674 ) . DEMOCRATIC REPUBLIC OF CONGO: 2 ♂♂ 3 ♀♀ Eala , 0.051157/18.315305, alt. 311 m, ii.1935, J. Ghesquière leg., det. Tjeder 1971 ( IRSNB 10482 ) . 1♀ Mabanga , 1.390802/19.101719, alt. 332 m, 28.vii.1952, P.N.G. Miss. H. De Saeger leg., det. Kimmins 1963 (3827, IRSNB 24.417 ) . 1 ♀ no collection locality, 01.iv.1950, P.N.G. Miss. H. De Saeger leg., det. Kimmins 1963 (I/b/1, IRSNB 24.417 ) . 1♂ Haut-Uele, Dika , -3.036321/20.015869, alt. 400 m, 24.iii.1925, Dr. H. Schouteden leg., det. Navás (R. DÉT. i 1475 MRAC) . GHANA [Gold Coast]: 1 ♂ Bibianaha near Dunkwa , 5.773108/-2.530935, approx. alt. 70 m, Sep.-Dec. 1909, Dr. Spurell leg., det. Gerstaecker ( NHMUK, 1911–291) . 1 ♀ region of Kibi (= Kyebi), 6.168326/-0.54942, alt. 294 m, Mont Atewa , 20.ii.1969, O.W. Richards leg., det. Tjeder 1975 ( NHMUK 1969–210 ) . 1 ♂ Aburi , 5.851184/- 0.172911, alt. 461 m, A.R. Gould leg. ( NHMUK, 1913–456) . 1 ♂ 1 ♀ same locality, 1912– 13 W. H. Patterson leg., Suhpalasca subcostalis det. Banks ( NHMUK 1915–397 ) . IVORY COAST: 1 ♂ Bouaké , 7.687788/-5.038746, alt. 35 m, 27.ii.1982, B. Michel leg. (Cirad-CBGP) . 1 ♂ M’Bahiakro , 7.454189/-4.341085, alt. 128 m, 10.v.1982, B. Michel leg. (Cirad-CBGP). NIGERIA : 1 ♂ Ibadan , 7.307823/3.960877, alt. 176 m, 23.ii.1960, L.A. Mound leg., light trap, det. Tjeder 1975 ( ZMHB 1961–203 ) . 1 ♂ Ana 44 (probably River Ana , 7.681944/8.263611), coll. Oboite, car. pap. leaf, 12.ii.1957, det. Tjeder 1985 ( MZLU 2016 171) . 1 ♂ 1 ♀ Batati * near Bida , 9.079679/ 6.009702, alt. 143 m, 30.iii.1959, Disparomitus maynei det. Kimmins 1961 ( NHMUK) . SIERRA LEONE: 1 ♀ no collection locality, W.G. Clements leg., det. van der Weele ( NHMUK 98–20 ) . 1 ♀ Tasso Island , 8.551517/- 13.076027, alt. 0 m, iv. 1920, W.P. Lowe leg., det. Gerstaecker ( NHMUK 1920–502 ) . 1 ♂ K20 (not located), 24.iii.1968, D.F.Owen leg., det. Tjeder 1972 ( MZLU 2016 172). TOGO : 1 ♂ Konkoa [Bismarckburg], 8.183333/ 0.683333, alt. 652 m, R.S. Büttner leg. ( ZMHB) .

* The first abdominal tergite of the male specimen is flattened dorso-ventrally and slightly asymmetrical with the bristles directed backwards ( Fig. 14 ). This shape, which is not characteristic of the genus Disparomitus , is most certainly due to a malformation. Given the other morphological characters, I consider that the two specimens collected in the same locality and at the same date belong to the species D. bacillus .

Distribution. Disparomitus bacillus seems to be an evergreen forest species of West and Central Africa that extends North up to the tree savannas of West Africa. The most northern collection locality, in the Northeast of Nigeria, is located near the 500 millimeter rainfall isohyet ( Fig. 139 ).

Figures

FIGURE 139. Known distibution of Disparomitus spp. (? = species recorded from the country without collection locality).

FIGURES 9–14. Suphalasca bacillus Gerstaecker. 9. Lectotype ♂ habitus, labels and museum card (photos EMAU). 10. Id., thorax and base of abdomen, vv (photo EMAU). 11.Id., lv (photo EMAU). 12. Base of abdomen of male from Ivory Coast, dv. 13. Id., lv. 14. Thorax and base of abdomen of male from Nigeria, dv, arrow shows deformed first abdominal tergite.

FIGURES 15–16. 15. Paralectotype ♂ of Suphalasca bacillus Gerstaecker, habitus, labels and paper envelope containing the abdomen. 16. Holotype ♀ of Suphalacsa subcostalis Navás, habitus and labels (photo MRAC).

FIGURES 84–95. Thorax and base of abdomen, dv. 84. D. abyssinicus. 85. D. bacillus. 86. D. brevistigma. 87. D. haullevillei (photo MRAC). 88. D. kimminsi (white arrow shows the black dot in the yellow marking). 89. D. lineatus. 90. D. schoutedeni (photo MRAC). 91. D. sellatus (photo MRAC). 92. D. simplex. 93. D. spatula. 94. D. transvaliensis. 95. D. caviceps.

FIGURES 96–113. Gonarcus-parameres complexes of Disparomitus spp. 96. D. abyssinicus type, dv. 97. Id., lv. 98. Id., cv. 99. Suphalasca bacillus type, dv. 100. Id., lv. 101. Id., cv. 102. D. bacillus from Ivory Coast, dv. 103. D. brevistigma from Democratic Republic of Congo, dv, 104. Id., lv. 105. Id., cv. 106. D. caviceps, dv. 107. Id., lv. 108. Id., cv. 109. D. citernii, dv. 110. Id., lv. 111. D. haullevillei, dv. 112. Id., lv. 113. Id., cv. (c = carina of paramere; g = gonarcus; p = paramere).