Pistosia testacea ( Fabricius, 1801 )

Sekerka, Lukáš, 2015, Wallacea, Pistosia and Neodownesia: three distinct genera and their tribal placement (Coleoptera: Chrysomelidae: Cassidinae), Acta Entomologica Musei Nationalis Pragae 55 (2), pp. 713-743 : 727-728

Pistosia testacea ( Fabricius, 1801)

Alurnus testaceus Fabricius, 1801: 25 (original description); SCHÖNHERR (1808): 342 (catalogue); BALY (1859): 162 (noted, incertae sedis supposedly belonging to Oxycephala ); ZIMSEN (1964): 118 (type).

Oxycephala testacea: GEMMINGER & HAROLD (1876) :3604 (catalogue); DONCKIER DE DONCEEL (1899): 556 (catalogue); WEISE (1905): 96 (noted, misidentification); GESTRO (1905): 457 (noted); WEISE (1911a): 47 (catalogue); WEISE (1911b): 70 (catalogue); MJÖBERG (1917): 18 (noted); UHMANN (1952b): 73 (noted).

Pistosia testacea: UHMANN (1957) : 108 (type, transfer, comparative notes); GRESSITT (1957): 302 (South Pacific fauna, transfer); UHMANN (1958): 229 (catalogue); UHMANN (1964):461 (catalogue); MARIAU (1999): 233 (noted); MARIAU (2001): 131 (noted).

Pistosia maculata [misidentification]: HELLER (1916): 116 (faunisticts).

Type locality. Original type locality: ‘Nova Cambria’ [= New South Wales], here corrected to: Indonesia, SE Sulawesi Province, Muna Island.

Type material examined. SYNTYPE: pinned (both antennae missing): ‘testaceus [w, hw by Fabricius, s] || Pistosia [hw] | testacea (J) [hw] | E. Uhmann det., 195[p]6[hw] | rev. [hw] [w, p, cb, hw parts by Uhmann]’ ( ZMUK, currently at ZMUC).

Additional material examined. INDONESIA: SOUTH- EAST SULAWESI: Kolaka Regency, Ahua Creek, 1 spec., Drs. Sarasin lgt. ( MTD).

Differential diagnosis. Pistosia testacea has stout body with pronotum distinctly wider than long like P. maculata but the latter differs in elytral intervals II, IV and VI costate, and densely punctate pronotum along sides from base to anterior corners, while P. testacea has at most the interval VI slightly costate, remaining ones flat and pronotum sparsely punctate with punctures not reaching anterior corners laterally. Both species also differ in punctation of elytra: P. maculata it is coarser and more densely arranged thus distance between two punctures within a row is less than the puncture diameter while P. testacea has punctation distinctly sparser with distance between two punctures equal or slightly larger than puncture diameter.

Distribution. Indonesia: South East Sulawesi (present paper).

Remarks. WEISE (1905) considered Oxycephala cornigera Guérin-Méneville, 1833 a colour form of O. testacea and this opinion was followed until UHMANN (1957) who studied the type of A. testaceus . UHMANN (1957) [1.xii.1957] and GRESSITT (1957) [20.xii.1957] both independently transferred Alurnus testaceus Fabricius, 1801 to Pistosia . UHMANN (1957) certainly studied the type specimen from the ZMUK collection as he published its photograph accompanied by detailed notes and comparison to P. maculata and concluded that both are distinct species. The basis of GRESSITTʼs (1957) decision is unknown as he gave only a brief comment. UHMANN (1957) considered both Pistosia species valid and stated that P. maculata differs in elytral intervals more elevated, apex of the elytra emarginate while P. testacea has a distinct denticle on the apex of suture.

HELLER (1916) reported specimens of P. maculata from ‘AhuaBach’ in southern Sulawesi collected by brothers Sarasins.According to their travel report ( SARASIN & SARASIN 1905) they walked along the Ahua Creek (approximately 04°02.4′S, 121°54.5′E, 50–60 m a.s.l.) through rich stands of the sago palm on 26 th February 1903 after Nangéu on trip to Raterate. HELLER (1916) stated that these specimens differ from the type, according to the figure published in Genera Insectorum ( WEISE 1911b), in the apical black spot on elytra not concavely delimited anteriorly but rather composed of two oval spots, one on each elytron, and considerably extending to explanate margin. I have examined one specimen from MTD ( Fig. 7 ) and it has dorsal colouration very similar to the syntype of P. maculata ( Fig. 6 ) except black colour expanding more laterally on explanate margins of elytra. However it does not have prominent costae on elytra like P. maculata and is in fact nearly identical to the syntype of P. testacea .

FABRICIUS (1801) described A. testaceus from the material collected by Jacques-Julien Houtou de Labillardière (1755–1834) and stated ‘Nova Cambria’ [= New South Wales] as the type locality. The depository of Labillardièreʼs insect collection is unknown, nor is it known whether the material he collected was retained by Fabricius or the specimen present in his collection came from somewhere else. Despite findings that many Fabrician specimens in his collection actually do not represent true types (see SEKERKA & BARCLAY 2014), I consider the specimen a syntype as it agrees with the primary description. However, the type locality must be erroneous because no other specimen nor any other species of Bothryonopini was collected in Australia. Assuming the specimen was collected by Labillardière during his voyage ‘à la Recherche de la Pérouse’ and taking in account the fact that so far all Pistosia specimens came from Sulawesi there is only one possibility where the specimen was collected. According to the itinerary of the voyage ( LABILLARDIÈRE 1802) they passed Sulawesi only once, on the way back to France. The other possibility could be also Buru Island where they stopped before travelling towards Sulawesi; other places are too distant from Sulawesi and thus it is unlikely the species occurred there. Below the travel from the Waigeo Island to Java is summarized.

They sailed on 28 th August 1792 from Waygiou [= Waigeo Is.] and on 4 th September reached northern coast of Bourou [= Buru Is.]. The boat anchored in the Kayeli Bay where they stayed for several days around village Cayelle [= Kayeli]. Labillardière mentioned seeing extensive plantations of the sago palm among other trees and plants. On 16 th September they sailed towards Straits of Bouton [= Buton Is.] which they reached on 22 nd. The straits proved difficult to pass and they sailed through as late as on 7 th October and anchored north of village of Buton [= Bau-Bau]. Labillardière mentioned going on the shore of Pangesani Island [= Muna Is.] and he noted that he gathered various species of rattans ( Calamus spp. ) and also stated: ‘In the Island of Pangesani, I several times traveled thick forests of the palm, known by the name of Corypha umbraculifera …’. Labillardière continues that on 8 th October they visited the village Buton to see the Sultan and on 9 th afternoon they sailed to Salayer [= Selayar Is.] which they passed and continued toward Java. Therefore it seems most probable that the specimen was collected in Pangesani Island, nowadays known as Muna Island. This is supported by the fact that the material published by HELLER (1916) as P. maculata is in fact conspecific with the syntype of P. testacea .

MARIAU (1999, 2001) wrongly assigned P. testacea to Cryptonychini and listed it as palmivorous without giving a reference.

Figures

Figs 1–7. 1 – Neodownesia mediovittata (Gestro, 1920) (Laos: Ban Song Cha, J, 8.7 mm); 2 – N. rubra Gressitt, 1953 (holotype, J, 6.5 mm); 3 – N. sita (Maulik, 1919) (Thailand: Soppong, ♀, 9.0 mm); 4 – Wallacea apicalis Gestro, 1896 (Indonesia: Mentawai Is.: Siberut, 5.3 mm); 5 – Pistosia terminalis (Baly, 1869) (holotype, 9.5 mm, © Natural History Museum, London); 6 – P. maculata (syntype, 12.0 mm, © Museum für Tierkunde, Berlin); 7 – P. testacea (Fabricius, 1801) (Indonesia: Sulawesi: Ahua Creek, 11.1 mm).