Cycadophila nigra

Skelley, Paul, Xu, Guang, Tang, William, Lindström, Anders J., Marler, Thomas, Khuraijam, Jibankumar Singh, Singh, Rita & Rich, Stephen, 2017, Review of Cycadophila Xu, Tang & Skelley (Coleoptera: Erotylidae: Pharaxonothinae) inhabiting Cycas (Cycadaceae) in Asia, with descriptions of a new subgenus and thirteen new species, Zootaxa 4267 (1), pp. 1-63 : 22

Nigra species group

Adult diagnosis. The Cycadophila (Cycadophila) nigra species group is easily distinguished from other members of Cycadophila by the dark brown to black body often with elytral markings; head dorsal surface convex in profile, most notable over frons and clypeus; supraocular stria present, short, <1/2 posterior length of eye; maxillary palpi normal in length, not more than 2× longer than labial palpi; ventral interocular distance approximately 1/2 head width; submental-gular suture primarily flattened, medially with depression between two pits, depression and pits variable in depth from just notable to sharply defined; pronotal angles sharply angulate, surface near anterior angle usually more convex (reflexed), lateral carinae straight most of middle length, basal margin appearing quadrate, straight at sides, angulate next to juncture with discal groove and pore, then evenly rounded (lobed) at middle; pronotal lateral carina thin in lateral view, with single row of setose punctation on marginal surface; prosternal process broad (>1/2 width of profemur), truncated at apex, apex not notably depressed, in lateral view flattened; protibia weakly dilated distally, lacking fringe of stout setae along apical and lateral margins, may have couple of stout setae at disto-lateral angle; coxal line behind mesocoxae usually with large deep punctures; male genitalia with tegmen moderately twisted basally, penile strut 5.00–6. 0 0× length of median lobe; and sexual dimorphism when present involves some modification to the male hind leg.

Remarks. Some members of the nigra species group are superficially similar in general appearance to Pharaxonotha kirschii (a New World species, occasionally reported as a stored product pest, the Mexican grain beetle; Hinton 1945; USDA 2015). The similarity is so striking that entirely dark specimens of the nigra group can be easily confused with P. kirschii . However, the presence of a small temple behind the eye, dorsoventrally flattened male genitalia, male with small tooth on apex of last abdominal ventrite, and distribution readily distinguish P. kirschii from the nigra group which mostly lack the temple, have twisted genitalia, and lack sexually dimorphic abdominal ventrites.

The striking similarity in general body plans between the cycad-inhabiting members of Pharaxonotha and those of Cycadophila other than the nigra species group, may be convergences based on similarities in life histories on cycads. In contrast, the superficial similarity of P. kirschii (the only Pharaxonotha sp. not associated with cycads) and those of the nigra species group, may indicate similarities in life histories not involving cycad cones. The general paucity of some of these species in available materials collected on cycads supports the hypothesis that some members of the nigra species group are not obligate cycad cone associates and may feed on other hosts.

The nigra species group is the most diverse group of Cycadophila . Molecular analyses of two species are presented in this paper and they are consistent with the concept of a monophyletic clade, but the variability in morphological characters of taxa lacking molecular data do not yet warrant naming of this group as a distinct subgenus or to split it up further.