Diploptera minor ( Brunner von Wattenwyl, 1865 )

Li, Xinran & Wang, Zongqing, 2015, A taxonomic study of the beetle cockroaches (Diploptera Saussure) from China, with notes on the genus and species worldwide (Blattodea: Blaberidae: Diplopterinae), Zootaxa 4018 (1), pp. 35-56 : 51

Diploptera minor ( Brunner von Wattenwyl, 1865)

( Figs. 4–5 , 57–59 , 72–75 )

Eleutheroda minor Brunner von Wattenwyl, 1865: 265 , locality Philippines; Walker, 1869: 125, placed in Diploptera .

Diploptera silphoides Walker, 1868: 57 , locality Philippines; Walker, 1869: 125, synonymized with D. minor ; Princis, 1957: 91, the lectotype was designated outside the syntypes.

Diploptera minor: Walker, 1869: 125 ; Princis, 1953: 208; Princis, 1957: 91.

Taxonomic notes. Princis (1953) stated that the tegmina of D. minor has punctations present on the basal part but fading out from the middle to the tip and regarded it as a diagnostic character in his key to species when compared with D. punctata , which as he said has punctations throughout the tegmina; however, this character is common among species which has moderately distinct punctations on the tegmina, including D. punctata .

According to the original descriptions by Walker (1868) and Brunner von Wattenwyl (1865), the syntypes of D. silphoides are obviously larger than those of D. minor (cp. body length 15.9mm vs. 11mm, males); however, these two species were simply synonymized by Walker (1869). Moreover, a specimen (female) outside the syntypes (males) of D. silphoides was designated as the lectotype by Princis in 1956 ( Princis 1957), of which the body length measures 15.5mm. On August 1, 1973, Roth (1973) made a genitalia slide of an undetermined specimen (NHM) from Samoa Islands, in his paper stating that its phallomeres were indistinguishable from D. punctata . That specimen was subsequently identified as D. minor by somebody although its locality is far away from Philippines, the type locality of this species, and though it is distinctly larger than the syntypes of D. minor . It measures 15.5mm and agrees with the description of D. silphoides by Walker (1868), we find it appearing to be a light-colored D. punctata or, with doubt, it could be a large-sized D. minor . One of the 5 specimens (NRM) from Philippines identified as D. minor by Princis (1953) has a similar situation, this female measures 16.8mm which is very reasonable when its male measures 15.5mm. Therefore, Walker’s D. silphoides seems to be an intermediate thing between D. minor and D. punctata , but we should follow previous taxonomist when there are not enough materials and believe the leg color to be more reliable than the body size.

In examining the male syntype of D. minor, Roth (1973) , who adopted McKittrick’s terms, stated “Except for size, the phallomeres of D. minor are almost indistinguishable from D. punctata ;” (cp. Figs. 73 & 74 with Figs. 34– 36 ) and “the sclerotization (L2d) of the prepuce found in D. punctata is absent in minor .” But we can see a small “L2d” (as apical sclerite of L2’ in the present study), even though the sclerotized area is so limited. Since this sclerite is varied in shape, its morphology is less valuable in specific taxonomy.

We examined all the 5 specimens deposited under an overall label as E. minor in NHMW. Three of them, as mentioned below, can be recognized as D. minor , whilst one from Hawaiian Islands is actually D. punctata , corresponding to its determination label “ Eleutheroda dytiscoides ”. Another one from Buru Island (of Maluku Islands) is also a D. punctata but has somewhat light-colored legs.

Since the characters used for dividing D. minor and D. punctata are body length and coloration, specimens with intermediate or mixed characters do provide taxonomists with a troubled situation.

Type materials examined. SYNTYPES ( NHMW) of Eleutheroda minor , 1 male & 1 female, “ Philippines, Coll. Br. v. W.” (collection of Brunner von Wattenwyl), coll. Dohrn; slide of the male SYNTYPE ( NHMW), “17. Vienna Mus., Diploptera minor Brunner , ♂ genitalia”, made by Roth (1973) ; LECTOTYPE (NHM) of D. silphoides , female, designated by “K. Princis 1956”.

Other materials examined. 1 male ( NHMW), “ Philippines, Mus. Caes. Vind.” (Rerum Naturalium Musei Caesarei Vindobonensis); 3 males 2 females ( NRM), “Ins. Philipp.”, coll. “ Semper ”; 1 male (NHM), “ Samoa Is.”, dissected by Roth.

Figures

FIGURES 2 – 16. Pronota of Diploptera spp. & subspp. presented in monochrome, i. e., white indicates unicolor or lighter coloration, whilst black is for darker portion. 2 – 3 D. punctata; 2 male; 3 female; 4 – 5 D. minor; 4 female; 5 male; 6 D. erythrocephala, male; 7 – 8 D. parva; 7 male; 8 female; 9 D. naevus sp. n., male; 10 D. nigrescens nigrescens, male; 11 – 12 D. nigrescens guani subsp. n.; 11 male; 12 female; 13 D. bicolor, male; 14 D. maculata, female; 15 – 16 D. elliptica sp. n.; 15 male; 16 female. (Dashed lines indicate depression. Scale bar = 2 mm)

FIGURES 57 – 65. Diploptera spp. distributed outside China, types and labels. Part 1 / 2: punctata - species-group except D. punctata. 57 – 59 D. minor (Brunner von Wattenwyl, 1865), male SYNTYPE (NHMW) from Philippines, photographed by Harald Bruckner, copyright © by Natural History Museum Vienna, NOaS Image Collection, published with permission; 60 – 62 D. erythrocephala Princis, 1950, male HOLOTYPE (MZLU) from Borneo, photographed by Ellen Sandström, photo courtesy of the Biological Museum, Lund University, Sweden; 63 – 65 D. parva Princis, 1953, male HOLOTYPE (NRM) from Java, photographed by Gunvi Lindberg, copyright Swedish Museum of Natural History, Stockholm (NRM). (Scale bars = 5 mm.)

FIGURES 72 – 75. D. minor (Brunner von Wattenwyl, 1865), genitalia slide (NHMW) of the male syntype. 72 terminal two segments of dorsal abdomen, in dorsal view; 73 subgenital plate and phallic sclerites, in dorsal view with a green arrow pointing the apical sclerite of L 2 ’; 74 apical part of sclerite L 3 ’ in detail, showing the curved tip; 75 overall view of the slide. (Excluding 74, photographed by Harald Bruckner, copyright © by Natural History Museum Vienna, NOaS Image Collection, published with permission. Scale bars = 500 µm for 72 & 73, 100 µm for 74.)

FIGURES 31 – 36. D. punctata (Eschscholtz, 1822) from China, Yunnan, Menglun. 31 hind wing, female, with grey coloration indicating sclerotization; 32 – 36 male; 32 terminal segment of dorsal abdomen, in ventral view; 33 subgenital plate in dorsal view; 34 – 36 phallic sclerites in dorsal view; 34 sclerites R’; 35 sclerites L 2 ’; 36 apex of left complex hook, showing sclerite L 3 ’. (ce. = cercus, m. = membranous, p. p. = paraprocts, st. = stylus; other abbreviations as indicated in the text. Scale bars = 10 mm for 31, 1 mm for 32 & 33, 500 µm for 34 – 36.)