Curtos cerea ( Gorham, 1882 )

Jusoh, Wan F. A. & Ballantyne, Lesley, 2024, A catalogue and redescription of type specimens of fireflies (Coleoptera, Lampyridae, Luciolinae) deposited in Naturalis Biodiversity Center, Leiden, Contributions to Entomology 74 (1), pp. 63-80 : 63-80

publication ID	https://doi.org/ 10.3897/contrib.entomol.74.e107520
publication LSID	lsid:zoobank.org:pub:E314C311-AE79-4679-8EB6-99B63B4E8965
DOI	https://doi.org/10.5281/zenodo.12172890
persistent identifier	https://treatment.plazi.org/id/9ECEAD3D-323E-564D-9556-361B4F8934EE
treatment provided by	by Pensoft
scientific name	Curtos cerea ( Gorham, 1882 )
status

Treatment

Curtos cerea ( Gorham, 1882) View in CoL

Fig. 2 A – V View Figure 2

Luciola cerea Gorham, 1882: 103–104; 1887: 70. Olivier 1902: 76. McDermott 1966: 101. View in CoL

Lectotype and paralectotype.

2 ♂ (herein designated).

Type locality.

“ Koetoer ”.

Material examined

(2 ♂ specimens). Lectotype (herein designated): INDONESIA ● ♂; (1) “ cerea ”; (2) “ Sum. Exp. / Koetoer / 6 / 78 ”; (3) “ Koetoer / 6.78 ”; (4) “ RMNH Leiden / ex Indo-Austr. / collection ”; (5) “ RMNH. INS / 968351 ” (Fig. 2 A View Figure 2 ) . Paralectotype: ♂; (1) “ Luciola / cerea ”; (2) “ Sum. Exp. / Lebong / 5 / 78 ”; (3) Lebong / 5 / 78 ”; (4) “ [?] ”; (5) “ RMNH Leiden / ex Indo-Austr. / collection ”; (6) “ RMNH. INS / 968360 ” (Fig. 2 B View Figure 2 ) .

Additional material examined

(2 ♂ non types). INDONESIA ● possibly ♂, abdomen missing; (1) “ Rawas / 5.78 ”; (2) RMNH Leiden / ex Indo-Austr. / Collection ”; (3) “ RMNH. INS / 968352 ” (Fig. 2 C View Figure 2 ) . ♂; (1) “ Cerea ”; “ Sum. Exp. / Alahan / pandjang / 4 / 9.77 ”; (2) A. pg. / 4 / 9.77 ”; (3) “ [?] ”; (4) “ RMNH Leiden / ex Indo-Austr. / collection ”; (5) “ RMNH. INS / 968361 ” (Fig. 2 D View Figure 2 ) .

Diagnosis.

The lectotype male, RMNH. INS 968351 (herein designated) and paralectotype, RMNH. INS 968360 differ in dorsal colouration but are here regarded as the same species. Dorsal surface orange yellow with somewhat diffuse median darker brown markings on pronotum (very faintly in specimen RMNH. INS 968360); elytra with apical brown area occupying approximately half the elytral length. The only other Curtos sp. described from the island of Sumatra Curtos rouyeri Pic has a reddish head. Not possible to distinguish this species from several other species having yellowish dorsum and black tipped elytra and these are discussed below.

Redescription of lectotype and paralectotype male.

Body length. 6.0 mm long. L / W 2.6.

Colour. Specimen with the accession number RMNH. INS 968351 (“ Koetoer ”; Fig. 2 E View Figure 2 ): pronotum orange yellow, with median dark brown area not well defined, narrow in anterior 1 / 3, not reaching to anterior margin, expanding in posterior 2 / 3, not reaching to posterior margin; MN and base of MS appear dark brown; Specimen with the accession number RMNH. INS 968360 (“ Lebong ”; Fig. 2 F View Figure 2 ) pronotum with very diffuse median dark area; elytra semi-transparent, slightly paler yellowish than pronotum, with mid-brown apical marking extending to suture, posterior margin, and apical 1 / 5 of length of lateral margin; dark marking extends obliquely across elytra including humeral carina to anterior 1 / 3 such that inner margin of elytra and suture along basal 2 / 3 its length are pale, with carina pale in basal 3 / 5; head between eyes dark brown, antennae and palpi brown; venter of thorax mid brown, base of legs light brown, tibiae and tarsi darker brown; anterior margin femora of legs 2, 3 mid brown; basal abdominal ventrites very dark almost black, LO in V 6, 7 creamy white, fills V 7 to posterior margin (Fig. 2 G View Figure 2 ); T 7, 8 pale semi-transparent yellow, remainder of tergites dark brown; dorsally reflexed tergal margins of T 6, 7 white, of remainder dark brown.

Pronotum (Fig. 2 H View Figure 2 ). Width less than humeral width.

Elytra (Fig. 2 I View Figure 2 ). Punctation semitransparent when viewed from beneath.

Head (Fig. 2 J View Figure 2 ). Antennal sockets close but not contiguous; mouthparts well developed; antennae longer than head width but less than twice head width; all flagellar segments elongate slender.

Abdomen (Fig. 2 G View Figure 2 ). Posterior margin of V 7 entire, broadly rounded, no MPP developed (Fig. 2 K View Figure 2 ). T 8 (Fig. 2 L View Figure 2 ) ventral surface flat, no ridges or flanges developed; paired anterior sections short, apically narrowed; median posterior margin shallowly emarginated; dorsal surface covered with elongate setae; median triangular area (wider at anterior end) densely covered with very short setae, area narrowing anterior to posterior emargination.

Aedeagal sheath (Fig. 2 M – R View Figure 2 ). Slightly asymmetrical; area of sternite anterior to tergite articulations broad, apically rounded (Fig. 2 M, P View Figure 2 ); posterior area of sternite smoothly emarginated along both sides, more deeply on right; posterior half of sternite membranous, apically rounded, densely hairy (Fig. 2 P View Figure 2 ); tergite much wider than posterior half of sternite (Fig. 2 M, P View Figure 2 ), appearing from below as two heavily sclerotised subparallel sided arms which connect with a similarly sclerotised transverse posterior margin at approximately 90 °; anterior sclerotised portion of tergite very short; posterior area (Fig. 2 M, N, P, Q, R View Figure 2 ) probably represented by paired separated hooked, apically acute, asymmetrical lobes visible to the sides of the sheath sternite when viewed from above (hooks arrowed; left lobe visible at left of sternite, right lobe to right (Fig. 2 M View Figure 2 ), right lobe visible to left of sternite (Fig. 2 P View Figure 2 ); lobes expand irregularly into pointed, hooked pieces which probably function for muscle attachment (Fig. 2 N, O, Q, R View Figure 2 ; pointed apices of both lobes visible).

Aedeagus (Fig. 2 S – V View Figure 2 ). ML slightly longer than LL; left LL slightly shorter than right (Fig. 2 S, U View Figure 2 ); apices of LL expand, irregularly truncate (longer on outer margin) with apex of left lobe longer on inner margin (Fig. 2 U View Figure 2 ); LL separate along median dorsal line and divergent towards their apices (Fig. 2 S View Figure 2 ); inner preapical margin of both LL with short pointed hook, visible only on R apex in 2 V (Fig. 2 S, V View Figure 2 ); anterior basal margin of LL widely produced (Fig. 2 S, T View Figure 2 ); BP subdivided into two elongate oval sections which are separated anteriorly (Fig. 2 S, U, V View Figure 2 ). Attachment of ML to LL (Fig. 2 S, T View Figure 2 ): lateral margins of postero dorsal area of anterior ML thickened, darkened, extend obliquely dorsally to converge (Fig. 2 T View Figure 2 arrow indicates area of convergence), and separate slightly just before they connect with the inner basal margin of the LL, well behind acute anterior margin of LL (Fig. 2 S, T View Figure 2 ; arrow in 2 S shows area of connection to inner margin of LL); nature of connection between these two areas not determined; inner margins of LL narrowly sclerotised, expanding slightly at base level with the point of attachment of the ML (Fig. 2 S View Figure 2 ), with the sclerotization extending anteriorly almost to anterior margin of LL base; entire median dorsal sclerotization considered to be reinforcing.

Notes.

After discovering that the specimens we subsequently assigned to lectotype and paralectotype status had been mixed in with other specimens, we took extra care to verify whether the additional specimens we examined were part of the type material or not. We meticulously examined each specimen to ensure we accurately identified the type-material, and our results were reliable. Our thorough examination allowed us to confidently identify the actual type specimens and exclude any specimens not part of the type material. However, because it is not possible to confidently identify so many similarly coloured Curtos species (see further below) we retained a list above of two further non type specimens which may aid in any future revision.

There is no recent revision of Curtos apart from Jeng et al. (1998) who addressed nine species from Taiwan and Japan. Ballantyne et al. (2009, 2013, 2015, 2016) scored characters for two Curtos species ( Curtos costipennis ( Gorham, 1880) and Curtos okinawanus Matsumura, 1918 ) and Fu et al. (2012) for two species. Ballantyne et al. (2019: table 15) listed 19 species and a further seven which were recommended for transfer from Luciola . Curtos is one of the few Luciolinae genera which can be immediately distinguished by external features only, including the well-defined elytral carina and the large evenly spaced elytral punctation, which occurs on both males and females.

In Gorham’s description of Luciola cerea , he noted the specimens he examined were all males (5–6 millimetres). He also listed six locations (see type localities) where the specimens were collected, which he referred to as “ (Sum. Exp.) ” for Sumatra Expedition. In the RMNH collection, we noticed four specimens with the species name marked on a label written in Gorham’s handwriting as “ cerea ” or “ Luciola cerea, Gorh. n. sp. ” or “ Luciola cerea ”. However, one specimen with the accession number RMNH. INS 968352 has “ Rawas ” as a locality label, which was not mentioned in the original description, but in Gorham (1887, in Ritsema). Therefore, we believe that it should not be considered part of type series. In addition to the four specimens, we also noted seven others in the collection (not pictured here): six from “ Koetoer ” and one from “ Kloempang ”. These specimens do not bear Gorham’s handwritten labels, but the locality labels are identical to the syntypes, i. e., from “ Sum. Exped ”. Because we believe that these were part of Gorham’s revision in 1887, they are not considered syntypes.

Ballantyne et al. (2019) listed the following species having pale yellow dorsum (including pale pronotum) and black elytral apices: Curtos atripennis Pic, 1934 , C. cerea , C. costipennis , Curtos flaviceps Pic, 1927 . Of these only C. cerea and Curtos rouyeri Pic, 1927 are from Indonesia. Of the other Luciola species recommended for transfer to Curtos the following all have the same basic dorsal colour pattern of pale-yellow dorsum with black elytral apices: (i) Luciola complanata Gorham, 1895 ; (ii) Luciola delauneyi Bourgeois, 1890 ; (iii) Luciola deplanata Pic, 1929 ; (iv) Luciola extricans Walker, 1858 ; (v) Luciola multicostulata Pic, 1927 and (vi) Luciola nigripes Gorham, 1903 . Most were described with some proportion (¼, ⅓, ½) of the elytral apex black.

A specimen with the accession number RMNH. INS 968352 has no abdomen for confirmation. Specimen with the accession number RMNH. INS 968361 (“ Alahan pandjang ”) is not consistent with the other two syntypes in being more slender and elongated (L / W 3.3) and there are no dark markings on the elytra.

Other remarks.

Little detailed work has been done thus far on species of Curtos and examination of these Leiden types allowed WFAJ not only to dissect them but to expose various new features of their morphology especially in the male genitalia. Clearly, comparisons with other species are not presently possible, and it is very probable that many of these species are synonyms. The hooked posterior lobes attributed here to the sheath tergite have not been seen elsewhere in the Luciolinae . Species of Sclerotia Ballantyne have irregularly shaped sclerites in a band of muscle which surrounds the aedeagal sheath in life. Both may have the same function, that of extra surface area for muscle attachment, but their origins appear to be different.