Acalolepta subgen. Dihammus Thomson, 1864

Acalolepta subgen. Dihammus Thomson, 1864 = Niphohammus Matsushita, 1932

Examined material

Acalolepta aesthetica (Olliff, 1890)

- 1 ♀, Australia, Queensland, Garradunga, Polly Creek , 12-I-2019, J. Hasenpusch leg., in CFV ;

- 1 ♀, ditto, 2-II-2019, in CFV ;

- 1 ♂, ditto 4-II-2019, in CFV .

Acalolepta artensis (Montrouzier, 1861)

- 1 ♂, 1 ♀, Nouvelle Caledonie, Prov. Sud, Sarraméa, 27-I-2006 / 25- I-2007, I. Jenis lgt., in CFV .

Acalolepta blairi ( Breuning, 1935) View in CoL

- 1 ♂, 1 ♀, SolomonIs., Malaita, south coast Hahorarumu, Urutribal area (conservation area), 100–250 m, 7/ 13-XII-2017, S. Jakl lgt., in CFV .

Acalolepta gracilis ( Breuning, 1938) View in CoL

- 1 ♂ HOLOTYPE, Nouvelle Guinée / Mons Bolan // Dihammus / gracilis View in CoL / mihi / det. Breuning Typ. [handwritten by Breuning and printed] // HOLOTYPE [printed on a red label], in RBINS.

Acalolepta puncticeps ( Breuning, 1938) View in CoL

- 1 ♂, Papua New Guinea, Sepik, Kerowai distr. , V.1991, in CDH ;

- 1 ♂, Simbu Prov., Kerowagi , in CGD ;

- 1 ♂, Marobe Prov. , Aseki-Meyamya, 2000 m, 12-IV-1998, A Riedel leg., in CAW ;

- 1 ♂, Eastern Highland Prov., Okapa , V-1992, loc. coll., in CAW .

Acalolepta riouensis ( Aurivillius, 1924) View in CoL - 1 ♂, Iles Riou, in MNHNP .

Remarks. – All examined species and, according to their original descriptions, A. sculpturata ( Aurivillius, 1924) and A. tugelensis Breuning, 1970 , should be transferred to the subgenus Dihammus .

Acalolepta puncticeps , described from Mt. Tafa ( Central Province , Papua New Guinea) is recorded for the first time for the provinces Chimbu, Eastern Highlands and Morobe .

The examined specimens bear an extraordinary resemblance to the specimen of A. riouensis preserved in the MNHNP. However, Aurivillius (1924) described this species from the “Riou Inseln” [= Riau Is., Indonesia], which is located between Singapore, Borneo and Sumatra, without any apparent geographical connection with New Guinea.

Another curious fact is that Aurivillius described in the same article Dihammus sculpturatus , a relatively large species ( 37 mm) from Java, also equipped with spined elytra. This character is exceptional among Asian species but extremely widespread in Australian ones. Both species came from the collection G. van Roons and only the types are known. Breuning (1961a) already considered the typical locality of sculpturatus as doubtful, having remarked a strong resemblance to A. bolanica ( Breuning, 1944d) . Thus, it is possible that both species were mislabelled and are actually Papuan species.

erworbenNachlass / R.Kriesche F. Tippmann, Wien [handwritten by Tippmann and printed] // TYPUS [printedon a red label] //BLNO / 000358 [printed on a sky-blue label], in USNM ;

- 1 ♂, Owgarra / B[ritish] N[ew] Guinea / Meek [printed] // Muséum Paris / 1952/ coll.A.Oberthür [printed on a white label] // Acalolepta / parabolanica / Breuning dét. Typ. [handwritten by Breuning and printed] // HOLOTYPE [printed on a red label], in MNHNP.

Remarks. – Aurivillius (1925) described Dihammus bolanicus from some specimens from different parts of New Guinea: Mt. Bolan, Mt. Goliath [= Mt. Yamin], Utaika river [= Utakwa river] and Mimika river. The first locality is located in Papua New Guinea (Suruwaged Mts., Morobe province) and the three remaining in West Papua.

KRIESCHE (1936) described Dihammus solatus nodias from Morobe province as well (a male from Mt. Bolan and a female from Sattelberg). He comparedthis specieswiththe Moluccan D.convexus Pascoe, 1866 , being uncertain whether it was a different species. Breuning (1944e) considered thistaxonomic placementas very doubtful, and Vitali (2010) recognised D. solatus nodias as synonym of D. bolanicus .

Finally, Breuning (1980) described A. parabolanica (Fig. 2) from three males from Owgarra ( Papua New Guinea, Central Province), which differed from A. bolanica in the head and pronotum without pubescence, the darker pubescence on the antennae, mesosternum and scutellum, as well as some relative characters of sculpture. Actually, they were old, greased specimens without peculiar characters; thus, A. parabolanica should be considered as another junior synonym of A. bolanica .

Additionally, Acalolepta bolanica should be transferred to the subgenus Dihammus due to the pre-apical tooth on the protibiae.

Acalolepta ( Dihammus) bolanica ( Aurivillius, 1925) View in CoL

( Fig. 1 -2)

= Dihammus bolanicus Aurivillius, 1925: 509 View in CoL or. comb.

= Dihammus solatus nodias Kriesche, 1936: 67 .

= Dihammus convexus nodias BREUNING, 1944e: 490 .

= Acalolepta parabolanica Breuning, 1980: 131 View in CoL n. syn.

Examined material

- 2 ♂, Indonesia, Irian Jaya, Wamena , 26-XII-1992, C. A. Casadio leg., in CFV ;

- 1 ♀, Bolan / G[e]b[ir]g // Dihammus / solatus nodias / Typ! [handwritten by Kriesche] // Dihammus / solatusPasc. / m. nodias / ♀ TypusKriesche / det. F. Tippmann, Wien [handwritten by Tippmann and printed] // Typus 1955 /

Acalolepta ( Dihammus) timorensis ( Breuning, 1935) View in CoL

( Fig. 3-4)

= Dihammus timorensis Breuning, 1935: 252 View in CoL ( Indonesia, Timor) or. comb. = Dihammus similis Breuning, 1938: 32 View in CoL ( Indonesia, Timor) n. syn.

Examined material

- Cypriola timorensis “ ALLOTYPE ”, 1 ♂, Timor Central, Soe, 880 m, ex coll. LeMoult, det. S. Breuning 1952, in RBINS;

- Dihammus similis HOLOTYPE, 1 ♂, Iles de la Sonde, Timor, ex coll. LeMoult, in RBINS;

- 1 ♀, Indonesia, Lesser Sunda , West Timor , Mutis Mts. , Molo Mt., Soe region, 500 m, XII-2015, loc. coll., in CFV ;

- 1 ♂, ditto, 10/ 20-I-2016, in CFV .

Remarks. – Breuning (1935) described Dihammus timorensis from some females belonging to the collection Itzinger (once in the Museum Frey, Munich, Germany; now, in the Naturhistorisches Museum Basel, Switzerland). Consequently, despite the label, the “ allotype ” preserved in the RBINS is not a type, as Cools (1993) claimed.Actually, it is a male that Breuning identified as Cypriola in 1952.

Subsequently, Breuning (1938) described Dihammus similis from a single male ( Fig. 4), indicating the larger body size (27 vs. 18–21 mm), different antennal proportions and imponderable relative characters of puncturing compared with D. timorensis . Finally, Breuning (1944d) added the description of the female, having antennae analogous to those of D. timorensis .

The examination of the holotype of D. similis has confirmed the suspicion that this species is actually a junior synonym of D. timorensis . The differences in the puncturing and body size are within the variability of this species, while other ones are typical sexual characters (antennal length and proportions).

Acalolepta timorensis shows the following characters: body length 18– 27 mm; male protibiae with pre-apical tooth;frons, vertex and pronotal disc covered with variable coarse punctures; scape inflated; antennae up to 3 times ( ♂) or 2 times ( ♀) as long as body; scutellum covered with pubescence analogous to that of body; elytra distinctly punctured to the apex, with irregular large patches of greyish-yellowish pubescence making little reflections. Tegmen lobes feebly convex.

Acalolepta timorensis View in CoL should be included into the subgenus Dihammus due to the pre-apical tooth on the protibiae. It is closely related to A. pseudobianor ( Breuning, 1935) View in CoL and A. rusticatrix (Fabricius, 1801) View in CoL , sharing analogous body size ( 20–29 mm in pseudobianor View in CoL , 18–25 mm in rusticatrix View in CoL ), antennal structure and pubescence ( Vitali, 2016). It mainly differs in the puncturing on the vertex and the stronger pronotal puncturing. Most probably, this species evolved through isolation from specimens of A. rusticatrix View in CoL dispersed along the Sunda Islands.

Acalolepta ( Dihammus) sexplagiata View in CoL n. sp.

( Fig. 5)

ZooBank: https://zoobank.org/ BF4264BA-077E-4BA8-85B3-08A98D71D612

Holotype, ♂, Indonesia, C.W. Sulawesi, Palu Reg., Palolo vill. env., III-2020, local collector, in CFV ( Fig. 5a).

Paraypes

- 1 ♀, ditto, in CFV ( Fig. 5b) ;

- 1 ♀, Sulawesi, Mamasa , III-2001, in CGD .

Description

General morphology. – Body length 21 ( ♂) to 21-24 ( ♀) mm. Habitus elongated; integument pitch-brown, covered with a dense brown and golden pubescence forming strongly changing patterns according to the direction of the light and three brown spots at the lateral margin of each elytron: a large pre-median one, sometimes embedding a lateral golden spot, a large post-median one and a small

4

pre-apical one; the space between the large spots is sometimes marked by a sutural light brown spot.

Head. – Forehead feebly ( ♂) or evidently ( ♀) transverse, covered with irregular strong punctures; eyes more than twice as long as cheeks; vertex relatively wide, smooth.Antennae long, about 2.5 ( ♂) or 1.75 ( ♀) times as long as body; antennomere V ( ♂) or VI ( ♀) not reaching the elytral apex; scape conical-fusiform, inflated in its apical third, truncated at apex, with an open apical cicatrix; antennomere III twice as long as scape; antennomere XI ( ♂) 1.75 times as long as X.

Pronotum. – Transverse, straight at apex, bisinuate at base, with a Vshaped furrow at apex and two transverse furrows at base; each side armed with a large conical tooth, whose apex is feebly tuberculate and perpendicularly directed; disc uneven, irregularly covered with some fine punctures and with three weak bulges on the disc, two anterior ones and a posterior one, reaching the apical and the basal furrows respectively.

Scutellum. – Trapezoidal to rounded, evidently transverse and densely pubescent.

Elytra. – Narrow (each elytron about 4 times as long as wide at base), feebly tapered to the apex ( ♂) or almost parallel-sided ( ♀); apex evenly rounded; disk covered with a dense pubescence and an almost regular puncturing vanishing on the apical third.

Legs. – Legs and tarsi of usual length, protibiae with an obtuse pre-apical tooth.

Ventral surface. – Last visible urosternite posteriorly more ( ♂) or less ( ♀) concave, without dense long recumbent pubescence at apex in male.

Differential diagnosis. – Due to itsdentate male protibiae, Acalolepta sexplagiata n. sp. belongs to the subgenus Dihammus , where it is well characterised by medium body size, rounded elytral apex and golden pubescence forming three almost regular brown spots on each elytron.

This pattern is very peculiar and is reminiscent of some species of the genus Epepeotes Pascoe, 1866 , such as E. lateralis (Guérin-Méneville, 1831) , E. diversus Pascoe, 1866 and E. plorator (Newman, 1842) , all widespread in Indonesia ( Breuning, 1943b).

Concerning the alliedspecies, Acalolepta sexplagiata n. sp. seems to be more closely related to the Philippine A. pseudobianor ( Breuning, 1935) , while the development of the stable dark pubescence is reminiscent of the Papuan A. tincturata ( Pascoe,1866) .In none of these species, however, the golden pubescence is so much developed. The Philippine A. fuscosericea (Schwarzer, 1931) shows a comparable pubescence (though not forming regular spots) but it is larger ( 17-30 mm), with a much more elongate body, obliquely truncated elytral apex and conical scape ( Hüdepohl, 1988). Finally, Acalolepta antenor (Newman, 1842) and its subspecies show a similar pubescence but slender body and more or less spined elytra apex ( Vitali, 2017b).

Species with golden pubescence are widespread in all distributional areasof the genus, e.g., A. permutans (Pascoe, 1857) and its subspecies, but males show mutic protibiae ( Vitali,2022); consequently,they belong to other subgenera. The most similar species look to be A. elijonnahdii Vitali & Fahri, 2019 and A. mattuladai Vitali & Fahri, 2019 , both widespread in Sulawesi, which are smaller ( 12–17 mm) and with a different elytral pattern (Vitali & Fahri, 2019).The Philippine A. tysoni Vitali, 2017 is much slenderer, with longer limbs and different elytral pattern ( Vitali, 2017a). Other species widespread in New Guinea, such as A. variolaris ( Pascoe, 1866) are more elongated and show less developed golden reflections.

Etymology. – The specific epithet is a combination of the Latin cardinal numeral “ sex ” (six) and the Latin adjective plagiatus, - a, - um (crooked, marked). It refers to the presence of the six tomentose spots on the elytra.