Amberderaeous Kim, Taszakowski & Jung, 2020

Kim, Junggon, Taszakowski, Artur, Herczek, Aleksander, Kim, Kwang-Ho & Jung, Sunghoon, 2020, A guest from the past: A new genus and a new species of Deraeocorinae (Hemiptera: Heteroptera: Miridae) in Miocene Dominican amber, Zootaxa 4819 (3), pp. 589-594 : 590-592

Genus Amberderaeous Kim, Taszakowski & Jung , gen. nov.

( Figs. 1 , 2 )

Diagnosis: Differs from other genera in Surinamellini by body elongated, not ant-like body; head relatively small; compound eye distinctly large, contiguous posteriorly; without longitudinal sulcus on vertex; antennae shorter than total body length; collar thin; pronotum undivided; lateral margin of pronotum straight; calli slightly swollen; scutellum almost flat in lateral view; lateral margin of hemelytra straight, not concave medially; cuneus well developed; tibia without long pubescence.

Description: Male: Body elongate, medium size. Coloration. Ground color dark brown. Head: almost pale brown, frons dark brown; clypeus pale brown; antennae near dark brown; first antennomere entirely dark brown; other antennomeres dark brown except for pale base. Thorax: pronotum with anterior part and lateral margin dark brown, posterior part slightly paler with dark punctures; scutellum near dark brown; evaporative area of metathoracic glands pale brown; hemelytra mostly pale, subhyaline, with anterior and posterior parts of corium dark brown; apical part of cuneus dark brown; membrane veins dark brown; legs mostly brown with dark patterning. Abdomen: pale brown, with pygophore dark brown. Surface and Vestiture. Body glossy, glabrous; pronotum with posterior part densely puncture; scutellum impunctate; hemelytra with dark punctures along with claval and R+M veins; tibia with distinct spines. Structure. Head: hypognathous in lateral view; vertex narrow, with weak longitudinal sulcus; frons narrow, tapered posteriorly; compound eye extremely large, contiguous, reaching anterior margin of pronotum; antennae shorter than body; first antennomere cylindrical, as thick as second antennomere; second antennomere near cylindrical; third antennomere longer than fourth; third and fourth antennomeres fusiform; labrum longer than 1/2 of first labial segment; labium exceeding slightly mid coxae. Thorax: pronotum trapezoid, undivided, length of pronotal midline slightly longer than 1/2 of basal width; calli slightly swollen; scutellum almost flat in lateral view; anterior width of scutellum longer than 1/2 of basal pronotal width; lateral margin of hemelytra weakly rounded; cuneus broad, length subequal width; legs slender; combined length of hind femur and hind tibia shorter than body length; first and second tarsomeres subequal in length, shorter than third tarsomere, combined length of second and third tarsomeres as long as 2.5x longer than first tarsomere ( Fig. 2D ); claw with basal tooth and setiform parempodia ( Fig. 2E ). Abdomen: not elongate, not reaching apex of cuneus.

Type species: Amberderaeous gigophthalmus sp. nov. by original designation.

Etymology: Named after combination of ‘ amber ’ as a fossil and ‘ deraeous ’ abbreviated form of the subfamily Deraeocorinae , referring to the deraeocorine group in amber; gender masculine.

Discussion: This new fossil taxon is most related externally to the extant genus Eustictus in the tribe Surinamellini , but it can be distinguished by calli region slightly swollen, scutellum flat, and the ‘compound eyes contiguous posteriorly’ which is unique in Deraeocorinae , even though large compound eyes with a narrow vertex are found in several Eustictus species (e.g. E. argentinus Carvalho, 1990 and E. membagilus Carvalho, 1991 ).

The genus Eustictus Reuter, 1909 is the most species rich in the Surinamellini ( Schuh 2002 –2013), all species possessing an elongate dorsal habitus and linear antennae ( Carvalho, 1955; 1987). However, the definition for this genus is still poor with few comprehensive characters, and there is no detailed study of morphological characters within the genus. Consequently, some species have been assigned to Eustictus solely because they possess the elongate dorsal habitus and linear antennae in Deraeocorinae , even though the types of genital structures are different. On the other hand, Carvalho (1990) erected the monotypic genus Guapimirella Carvalho which is also similar to Eustictus externally, based mainly on the difference of genital structure. It suggests the nominal genus Eustictus could comprise subgroups as related genera actually, and it is in needs of revision in details morphologically. Therefore, in order to infer related groups with this new fossil genus, phylogenetic analysis is needed using more detailed data, because the genital characters of fossil genus are unavailable.

We here indicate the tribal placement of Amberderaeous gen. nov. as the tribe Surinamellini in which its most closely related genus Eustictus is placed, in agreement with the current classification ( Schuh 2002 –2013). This tribe has been represented by the unusual character within Deraeocorinae , a strongly myrmecomorphic habitus (see Hernández & Henry 2010; Ferreira et al. 2015 for details), and indeed several genera such as the type genus Surinamella are myrmecomorphic (see fig. 21 ( Surinamella doesburgi ) in Ferreira et al. 2015 and fig. 1i ( Nicostratus diversus ) in Cassis & Schuh (2012) and comments on African myrmecomorphic genera in Schuh (1974)) ( Carvalho & Rosas 1962; Akingbohungbe 1980). However, in case of the several genera including Eustictus , it is ambiguous whether the habitus of each genus can be considered to be myrmecomorphic, comparing to the ant-like genera (see figs. 20 and 21 ( Eustictus versus Surinamella ) for comparison in Ferreira et al. 2015). At first, the genus Eustictus was placed in the subfamily Mirinae by Reuter (1909) and was finally placed to Surinamellini by Carvalho (1987). There are several important studies on phylogeny and classification of Deraeocorinae groups (e.g. Stonedahl & Cassis (1991), Cassis (1995), Chan & Cassis (2019)). However, the genera in Surinamellini such as the genus Eustictus have not been tested yet for its placement. Meanwhile, it has been shown that Eustictus is nested to Deraeocoris s. str. in the Deraeocorini based on total evidenced phylogeny for Deraeocorinae (unpublished data). Therefore, future comprehensive phylogenetic study of the taxonomic position of new genus with other related genera is needed, as Akingbohungbe (1978) mentioned, even though we here, for the moment, place this new fossil genus in the tribe Surinamellini .

Figures

FIGURE 1. Dominican amber with insect (A) and Amberderaeous gigophthalmus sp. nov. (B). Scale bar: 1 mm.

FIGURE 2. Amberderaeous gigophthalmus sp. nov. A: dorsal view; B: lateral view; C: compound eyes and pronotum; D: hind tarsus; E. claw structure. Scale bar: A–B: 1 mm; C: 0.5 mm; D: 0.3 mm; E: 0.1 mm.