Sychnomerus Bates, 1885,

Santos-Silva, Antonio, Botero, Juan Pablo & Wappes, James E., 2020, Neotropical Acanthoderini (Coleoptera, Cerambycidae, Lamiinae): Synonymies and new status in some genera, new species, transferences and new distributional records, Papéis Avulsos de Zoologia 60, pp. 1-40: 2

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Sychnomerus Bates, 1885


Sychnomerus Bates, 1885 

The definitions of the above acanthoderine genera have seen numerous changes since their original descriptions. These changes have resulted in modifications in their status (some more than once) making for a complicated history. In the most part their original descriptions have not allowed taxonomists to clearly understand their limits, and as a result new species have been assigned to them that changed their limits. Thus, making the study of this group of genera even more complicat- ed and difficult. Santos-Silva & Nascimento (2018) commented about the differences between Acanthoderes  and Psapharochrus  , and reported: “Apart from those controversial classifications,it was Lacordaire (1872) who provided the best feature to separate Psapharochrus  (including Symperasmus  as a synonym) from Acanthoderes (Acanthoderes)  and A. ( Scythropopsis  ). The former was included among the genera with eyes coarsely or sub-coarsely granulated, while the two latter genera were included among those with eyes finely granulat- ed.” Lacordaire (1872) also included Aegomorphus  in the group of genera with eyes coarsely granulated, and separated it from Psapharochrus  in the key by the genal length (translated): “Genae very short, sometimes nearly absent”, leading to Aegomorphus  ; and“Genae, at least, with medium size”, leading to Psapharochrus  . However, the genae in the type species of Aegomorphus  , Aegomorphus decipiens Haldeman, 1847  ( Figs. 4-6View Figures 1-9) (= Lamia modesta Gyllenhal, 1817  ( Figs. 41View Figures 35-42) = Aegomorphus modestus  ), is distinctly long, as in the type species of Psapharochrus  , Acanthoderes cylindricus Bates, 1861  ( Figs. 7-9View Figures 1-9). Actually, the genal length is longer in the type species of the former than in the latter, and Aegoschema sensu Lacordaire (1872)  is equal to Aegoschema Aurivillius, 1923  . This becomes clear when seeing the species originally includ- ed in Aegomorphus  by Lacordaire (1872): A. adspersus Thomson, 1861  ; A. moniliferus White, 1855  ; and A. obesus Bates, 1861  . But it is curious to note that Aegomorphus decipiens Haldeman, 1847  , type species of the genus, was included in Psapharochrus  by Lacordaire (1872). The problem here was that Lacordaire (1872) wrongly attributed the authorship of the Aegomorphus  to Thomson (1861), considering Aegomorphus Haldeman  as a synonym of Psapharochrus  . Evidently, thus occurred because Haldeman (1847) attributed the authorship of Aegomorphus  to Dejean (1835) followed by a correction of this by Aurivillius (1923): “ Aegoschema  n. nom. / Aegomorphus Thoms.  (nec Hald. 1847).”

Santos-Silva & Nascimento (2018) summarized their conclusions as follows:“1. Symperasmus  – probably a synonym of Psapharochrus  , but, at least, it must be considered a subgenus of Psapharochrus  . 2. Pardalisia – probably a synonym of Acanthoderes  ; 3. Scythropopsis  – probably a genus distinct from Acanthoderes  ; 4. Eyes very finely granulated – Acanthoderes (Acanthoderes)  ; A. (Pardalisia); A. ( Scythropopsis  ). 5. Eyes coarsely or moderately coarsely granulated – Psapharochrus  ; A. ( Symperasmus  ).” However, at that time they did not formally propose any change in the status of those genera.

A study of the type species of Aegoschema  and Psapharochrus  has revealed that they share the same features and lack significant differences hence we conclude that they are not different genera. Accordingly, we formally synonymise Psapharochrus  with Aegomorphus  . Although, it is important to note that several species currently placed in Psapharochrus  which have the lateral tubercles of the prothorax with the apex blunt (not acute as in the type species) and the elytra gradually narrowed from humerus to apex (not parallel-sided as in the type species), indicates that they are likely not true Psapharochrus  and thus, not Aegomorphus  either.