Malthodes (Malthodes) immortalis, Parisi & Fanti, 2020

Parisi, Francesco & Fanti, Fabrizio, 2020, Baltic amber: A new Cacomorphocerus Schaufuss, 1892 with two specimens preserved in a single piece, and four new Malthodes Kiesenwetter, 1852, Zootaxa 4778 (3), pp. 546-560 : 551-553

Malthodes (Malthodes) immortalis PARISI & FANTI sp. nov.

( Figs. 5–6 , 11B )

Description. Male, winged. Body length 4.0 mm; elytra 2.5 mm; pronotum 0.4 mm; antennae 3.2 mm. Entirely dark brown, without yellow spots on elytral apex.

Head exposed, rounded, with dense pubescence and shallow punctation. Eyes very large, rounded, prominent, inserted in the lateral-upper part of the head. Maxillary palpi 4-segmented, with the last palpomere globular and distally pointed. Labial palpi 3-segmented, last palpomere globular and distally pointed. Antennae filiform, 11- segmented, reaching the elytral apex and slightly surpassing the middle of the abdomen; antennomere I elongate, club-shaped; antennomere II about 2.2 times shorter than antennomere I; antennomere III slightly longer than antennomere II; antennomeres IV–VIII sub-equal, slightly longer than antennomere III; antennomeres IX–X shorter than previous ones; antennomere XI longer than previous and with rounded apex; all antennomeres densely covered by long setae. Pronotum transverse, as wide as head, surface punctate and covered by short setae, anterior and posterior margins straight and strongly bordered, sides almost straight and slightly bordered especially near the rounded posterior corners. Elytra short, reaching the base of the seventh abdominal segment, wider than pronotum, surface rugose and covered with sparse long setae, parallel-sided, rounded at apices. Hind wings infuscate, surpassing elytra and reaching the last abdominal segment. Legs long, slender, densely pubescent; coxae elongate and curved; trochanters elongate with rounded apex; femora slightly enlarged and slightly curved; tibiae cylindrical with a robust spur near the apex, pro- and mesotibiae shorter than pro- and mesofemora, metatibiae longer than metafemora; tarsi 5-segmented, pubescent; tarsomeres I thin, elongate; tarsomeres II 1.5 times shorter than tarsomeres I; tarsomeres III short and robust; tarsomeres IV strongly bilobed and robust; tarsomeres V elongate and slender; claws simple. Metasternum sub-quadrate. Sternites transverse and pubescent. Penultimate tergite (tg9) elongate and broad; last tergite (tg10) in the shape of a lobe, very small, triangular-shaped with rounded apex, pubescent; last sternite (st9) elongate, slightly curved, flat and robust from the base to the middle, apically forked (with lobes deeply forked, and rounded at their apex). Aedeagus little visible. Female unknown.

Etymology. Derived from the Latin adjective immortālis = immortal, eternal. In reference to the fact that remaining perfectly embedded in amber, and with our finding and description, it is “still alive”.

Holotype. Male, in Baltic amber, deposited at the University of Molise (Unimol) with accession No. Unimol AAA005FP. Type locality. Yantarny mine, Sambian Peninsula, Kaliningrad region, Russia. Type horizon. Middle Eocene (Lutetian) (47.8–41.2 MYA) to Late Eocene (Priabonian) (37.8–33.9 MYA). Syninclusions. Air bubbles, debris, stellate hairs, three Diptera ( Tipulidae : 1, Psychodidae : 2), Hemiptera (2 specimens).

Differential diagnosis. Three fossil species of Malthodes have the last urites similar to those of M. immortalis sp. nov. Malthodes sucini Kuśka & Kania, 2010 has the last tergite more elongate and cylindrical, while Malthodes moellehavei Fanti & Damgaard, 2018 has smaller dimensions and the last tergite enlarged apically and not triangular ( Kuśka & Kania 2010; Fanti & Damgaard 2018). Furthermore, Malthodes ceranowiczae Kuśka & Kupryjano- wicz, 2005 has slender last sternite and also last tergite rectangular and shorter ( Kuśka & Kupryjanowicz 2005). Malthodes immortalis sp. nov. is extremely similar to Malthodes unimol sp. nov. (see the differential diagnosis of the latter).

Remarks. The yellow amber piece measures 31 x 17 x 7 mm. The inclusion is complete, and well visible.

Figures

FIGURE 5. Malthodes (Malthodes) immortalis sp. nov. in Baltic amber (UNIMOL AAA005FP). Holotype, dorsal view, scale bar = 500 μm.

FIGURE 6. Malthodes (Malthodes) immortalis sp. nov. in Baltic amber (UNIMOL AAA005FP). A: Holotype, ventral view, scale bar = 500 μm. B: Holotype, detail of antennae, scale bar = 500 μm. C: Holotype, detail of last tergite (ventral view), scale bar = 200 μm. D: Holotype, detail of last sternite, scale bar = 200 μm.

FIGURE 11. A: Malthodes (Malthodes) giannii sp. nov. Reconstruction of the last abdominal segments, scale bar = 25 μm. B: Malthodes (Malthodes) immortalis sp. nov. Reconstruction of the last abdominal segments, scale bar = 400 μm. C: Malthodes (Malthodes) marialuisae sp. nov. Reconstruction of the last abdominal segments, scale bar = 200 μm. D: Malthodes (Malthodes) unimol sp. nov. Reconstruction of the last abdominal segments, scale bar = 100 μm.