2 research outputs found
Recommended from our members
A revision of the North American species of Pactopus Leconte and Trixagus Kugelann (Coleoptera: Throscidae)
This study was undertaken to find means of separating the
morphologically similar species of North American Trixagus and to
bring together information on Trixagus and Pactopus.
A key to separate the world's eight genera of extant Throscidae
is presented for the first time. A key to the five species of North
American Trixagus, as well as illustrations and detailed descriptions
of each species, are included to facilitate identification. In addition,
detailed distribution records and range maps are provided for each
species. No new taxa are proposed, but four species are retained
in synonymy after examination of the type specimens.
An investigation of external morphology found that color, size,
punctation, and pubescence are too variable to be useful characters.
Useful characters at the specific level are habitus, number of eye
facets, pronoto-elytral ratio, and genitalia. Secondary sexual
characteristics are shape of pronotum, size of eyes, and presence of
a fringe of setae on the elytra of the males of some species. Sixteen
additional structures were investigated. Six new morphological terms
are proposed for structures peculiar to Throscidae.
Trixagus Kugelann 1794 is adopted in preference to the more commonly
used Throscus Latreille 17.96 because the latter is shown to be a
junior objective synonym.
Two dendrograms show the relationships between North American
Trixagus, Aulonothroscus, and Pactopus and between the species
of Trixagus and fossil Pactopus. Pactopus is considered more
specialized than Trixagus or Aulonothroscus.
Methods of collecting throscids that were found to be most effective
were beating trees on warm evenings or by processing litter via a
berlese funnel. It was found that throscids are capable of clicking in
the manner of Elate ridge, despite numerous statements in the literature
to the contrary