Artonini
Tribe Details
The original definition by Tarmann (1994) of the Artonini has been mentioned in the account of the Procridinae. A more recent and more extensive account has been provided by Tarmann (2004) in his treatment of the Australian fauna where the Artonini are the only tribe represented. This publication includes numerous stereoscan photographs and other illustrations of the characteristic features, such as the triangular chaetosemata extending between the ocellus and compound eye. It presents a phylogeny for the Australian genera that also includes some of the Oriental tropical genera known from Borneo.
Most Asian Artonini have an unusual, single, medial hind-tibial spur that does not appear to be derived simply by modification of the usual medial pair of spurs, and tends to be somewhat more distal in position (Efetov & Tarmann, 1996).
The male genitalia in many species have a finger-like structure (the ‘Artona finger’) that is inserted ventrally at the distal end of the valve. It is mobile, jointed, and may bear brush-like setae.
The persistence of gland-like structures on abdominal segments 2 and 7 from late instar larvae through the pupa to the adult has already been mentioned; these are illustrated by Tarmann (2004). Efetov et al. (2006) suggested that presence of only one dorsal seta on segment A1 in first instar larvae is another apomorphy of the Artonini; there are two or more in all Procridini.
The phylogenetic analysis of Tarmann (2004) placed Thyrassia Butler in an outlying position, together with four Australian genera, three of these forming a clade characterised by presence of the finger-like structure in the male genitalia and a single medial hind-tibial spur, and with larvae feeding on monocotyledonous plants. Tarmann stated that Thyrassia is a unique and highly derived genus with many morphological reductions and striking apomorphies in the adult and larvae; it currently has no close allies identified. Thyrassia was the only artonine genus included in the molecular analysis of Niehuis et al. (2006).
