Lamacoscylus humilis (Bates, 1881)

Santos-Silva, Antonio, Heffern, Daniel, Botero, Juan Pablo, de, Francisco Eriberto & Nascimento, L., 2020, Notes, new records, new combinations, a new genus and three new species in Hemilophini (Coleoptera: Cerambycidae: Lamiinae), Insecta Mundi 2020 (785), pp. 1-25 : 3-4

Lamacoscylus humilis (Bates, 1881)

( Fig. 4 , 7–12 )

Malacoscylus humilis Bates 1881a: 223 ; Gahan 1892: 270; Aurivillius 1923: 586 (cat.); Blackwelder 1946: 623 (checklist); Gilmour 1965: 623 (cat.).

Hemilophus humilis ; Lameere 1883: 74 (cat.).

Lamacoscylus humilis ; Martins and Galileo 1991: 628; Chemsak et al. 1992: 159 (checklist); Monné and Giesbert 1994: 286 (checklist); Monné 1995: 9 (cat.); Noguera and Chemsak 1996: 408 (checklist); Monné 2005: 484 (cat.); Monné and Hovore 2006: 263 (checklist); Martins et al. 2015: 99 (key); Ordóñez-Reséndiz and Martínez- Ramos 2017: 828 (distr.); Monné 2020: 706 (cat.); Bezark 2019: 304 (checklist).

Bates (1881a) based Malacoscylus humilis on a single male from Mexico (Zacatepec – there are several places of this name, in several states) ( Fig. 4 ). Malacoscylus Thomson, 1868 was redescribed by Bates (1881a), who stated that “the third antennal joint alone in this genus is clothed with long hairs.” However, the species of Malacoscylus (there are species included that may not belong to the genus) have the antennomere III much longer than IV, and with abundant erect setae throughout. In Lamacoscylus Martins and Galileo, 1991 , the antennomere III is also longer than IV, but not much longer, and the erect setae are sparser, especially dorsally. Accordingly, we think that the decision of Martins and Galileo (1991) to erect a new genus was correct.

The male holotype of M. humilis has the antennomere III cylindrical and almost as wide as the other antennomeres. According to the original description of Lamacoscylus , the erect setae on antennomere III in females are denser than in males. Apparently, this information was based on the antennomere III of the holotype female of Malacoscylus usingeri Linsley, 1935 .

According to Gahan (1892), “One male specimen only was known to Mr. Bates when he wrote his description. Mr. H. H. Smith has since sent a long series, including both male and female examples, from the following localities in Guerrero: – Omilteme (8000 ft.), Xucumanatlan (7000 ft.), and Chilpancingo (4600 ft.). The female differs from the male by its somewhat shorter and relatively broader form; by its shorter, thicker, and more densely fringed third antennal joint; […] In some examples of both sexes the fulvous vittae of the prothorax have extended dorsally so as to cover part of the anterior half of the disk; while in one small male almost the whole upper surface of the head and prothorax is covered with fulvous pubescence. These examples differ in no other respect from the typical form, with which they are, in fact, connected by almost insensible gradations. It is otherwise with the two following varieties [ M. humilis var. grisescens , and M. humilis var. fulvescens ], which might indeed, with some show of reason, be regarded as distinct species.” Although Gahan (1892) did not make very clear the general appearance of the antennomere III in females of M. humilis at his disposal, it is possible to infer that it is as in the syntype female of M. humilis var. grisescens ( Fig. 6 ). However, the female examined by us ( Fig. 10–12 ), has the antennomere III at most only slightly thicker than in the male ( Fig. 7–9 ), and has the erect setae very similar. Accordingly, in our opinion Gahan (1892) confused males and females of the true M. humilis (thinking they were all males), which becomes evident because we have a couple also collected by H. H. Smith from a place listed by him. Malacoscylus humilis sensu Gahan (1892) appears to be a mix of at least two species, but most likely three species (see also comments under Schmidarius grisescens (Gahan) and S. flavescens (Gahan)) .

Material examined. MEXICO, GUERRERO: Omilteme (8000 ft.), 1 male, 1 female, July (no further details), H. H. Smith col. ( MZSP – donated by F. Du C. Goodman, 1907).

Figures

Figures 1–6. Habitus of Hemilophini spp.1–2) Cirrhicera leuconota, dorsal habitus.1) Holotype female (Hemilophus leuconotus). 2) Male.3) Lamacoscylus albatus, male, dorsal habitus.4) Malacoscylus humilis (Lamacoscylus humilis), holotype male, dorsal habitus. 5) Malacoscylus humilis flavescens (Schmidarius flavescens), syntype male, dorsal habitus. 6) Malacoscylus humilis flavescens (Schmidarius grisescens), BMNH specimen identified by Bates, dorsal habitus.

Figures 7–12. Lamacoscylus humilis. 7–9) Male.7) Dorsal habitus.8) Ventral habitus.9) Antennomere III.10–12) Female. 10) Dorsal habitus. 11) Ventral habitus. 12) Antennomere III.