Melanoclusia bivibrissaOwen Lonsdale and Steve Marshall
Melanoclusia Lonsdale & Marshall is represented by the single species M. bivibrissa Lonsdale & Marshall, which is known from only one male and one female from Borneo (Lonsdale & Marshall, 2008). While not observed in the field, the unusual colouration and chaetotaxy of this species suggests that behaviour plays an important role as a secondary sexual character – this has been documented in many other species of Clusiidae with similar morphology, including those in the behaviourally fascinating Heteromeringia Czerny, Clusiodes Coquillett and Hendelia Czerny. The discovery of this genus is significant in that it has important ramifications for understanding the evolutionary history and biogeography of the Clusiidae, both as a “missing link” in the subfamily Clusiinae and as the sister-group to the common Holarctic/Oriental genus Clusia Haliday.
Melanoclusia is unusual in appearance, differing from Clusia (the most closely related genus) and all other Clusiidae in having only one pair of dorsocentral bristles, no dorsal preapical tibial bristles, a vibrissa-like anterior genal bristle, a shiny frons with no interfrontal bristles, a rounded frons and face, a white vein dm-cu and dark colouration. The external male genitalia are similar to those of Clusia, but the internal components are unusual in that they are extremely elongate, projecting far into the abdomen.
Reduced postverticals and male-specific characters support a relationship with Clusia, but Melanoclusia bivibrissa lacks all of the distinct external synapomorphies used to separate that genus from other Clusiidae (interfrontal bristles, pubescent arista and striped scutellum). It is for this reason that Melanoclusia bivibrissa is treated as the sister group to Clusia and not a highly derived basal species of that genus. The male characters supporting a relationship between Melanoclusia and Clusia include the following: two rows of posteroventral bristles on the fore and mid femora (also found in the Chilean Clusiidae and Clusiodes), an inner-basal spur on a small, triangular surstylus, a uniquely-shaped pregonite (long, thin, minutely setulose along length and closely-associated with base of phallapodeme) and absence of the lateral lobes of the distiphallus (independently lost in some Sobarocephalinae and most Clusiodinae).
Lonsdale, O. & Marshall, S.A. 2008. Synonymy within Clusia and description of the new genus Melanoclusia (Diptera: Clusiidae: Clusiinae). Annals of the Entomological Society of America 101(2): 327-330
Canadian National Collection of Insects, Arachnids & Nematodes
University of Guelph, Canada
Correspondence regarding this page should be directed to Owen Lonsdale at and Steve Marshall at
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- First online 03 June 2008
- Content changed 24 November 2009
Citing this page:
Lonsdale, Owen and Steve Marshall. 2009. Melanoclusia http://tolweb.org/Melanoclusia_bivibrissa/67805/2009.11.24 in The Tree of Life Web Project, http://tolweb.org/. Melanoclusia bivibrissa . Version 24 November 2009.