Phytotelmatrichis, Darby, Michael & Chaboo, Caroline S., 2015

Darby, Michael & Chaboo, Caroline S., 2015, Phytotelmatrichis, a new genus of Acrotrichinae (Coleoptera: Ptiliidae) associated with the phytotelmata of Zingiberales plants in Peru, Zootaxa 4052 (1), pp. 96-106 : 99

Phytotelmatrichis gen. n.

The new genus is placed in the Acrotrichinae on the basis of the presence of lateral spines on each side of the metascutellum, considered by Hall (2000) to be diagnostic of the subfamily, and by its overall similarity to Acrotrichis Motschulsky 1848 . Careful consideration was given to establishing Phytotelmatrichis as a subgenus of Acrotrichis but the almost adjacent metacoxae, the form of the mesoventral collar which does not reach the lateral margins of the mesoventrum, the shape of the hind angles of the pronotum which barely project rearwards in lateral view, and the form of the spermathecae are considered sufficiently distinct to justify a separate genus. These features also establish the new genus as separate from Actinopteryx . Given that Actinopteryx also favours wet habitats (coastal debris), other morphological homologies were looked for with that genus but not found.

From the three remaining genera in the Acrotrichinini the new genus is distinguished as follows. Both Chirostirca Johnson 1985 and Petrotrotrichis Darby 2015 include species in which the mesoventral collar does not reach the lateral margins of the mesoventrum like that in the new genus, but these are both globose and very polished insects clearly distinct from Phytotelmatrichis . Storichrica Johnson 1988 also possesses adjacent metacoxae but the mesoventral collar in that genus and the form of the pygidium are very different.

Body elongate, broadest across the pronotum and tapering posteriorly, dorsal surface including the head pubescent. Colour variable from dark brown to yellowish brown. Eyes large and placed on the ventral surface of the head. Antennae with 11 antennomeres, I–II forming the scape and pedicel being much larger than III–XI, and IX–X forming a loosely formed and tapering club; all antennomeres bearing long setae. Sides of pronotum with a narrow raised margin, posterior margin not sinuate before hind angles which are barely produced backwards in side view when the pronotum is horizontal. Scutellum triangular without distinguishing features. Elytra truncate apically exposing +/- 4 abdominal segments. Proventrum narrow in front of the procoxae. Hind wings of usual featherwing type. Mesoventral collar not reaching to the lateral margins in ventral view, mesoventrum with a raised, setae-bearing keel between the mesocoxae extending anteriorly to meet the collar. Metasternum pubescent, posterior margin between the metacoxae very short, with sharp lateral points. Metacoxae with large rounded plates reaching to the lateral margins. Abdominal tergites II–V with wing folding spicule patches. Pygidium composed of tergites IX and X fused seamlessly together with three teeth, the two lateral teeth being much larger than the apical tooth which is often abraded. Abdominal ventrite I without femoral lines. Male ventrite VIx with a more or less curved excision, ventrite VII small with two fine setae on the posterior margin, covering the excision in ventrite VI, and with an anteriorly directed apodeme. Aedeagus symmetrical in dorsal/ventral view, crescent shaped. Spermatheca well developed.

In the following descriptions the measurements were taken from a range of specimens chosen to represent the extremes. Numbers in brackets refer to incomplete specimens and to fragments where there are sufficient to indicate a separate specimen, and are in addition to the preceding totals.