Gahniacarus, Beard, Jennifer J. & Ochoa, Ronald, 2011

Beard, Jennifer J. & Ochoa, Ronald, 2011, New flat mite genera (Acari: Trombidiformes: Tenuipalpidae) associated with Australian sedges (Cyperaceae), Zootaxa 2941, pp. 1-37 : 3-4

publication ID

https://doi.org/ 10.5281/zenodo.204686

DOI

https://doi.org/10.5281/zenodo.5612522

persistent identifier

https://treatment.plazi.org/id/0A68182D-FF81-F864-FF39-FF46E965FADA

treatment provided by

Plazi

scientific name

Gahniacarus
status

gen. nov.

Gahniacarus gen. nov. Beard & Ochoa

Type species. Gahniacarus tuberculatus Beard & Ochoa

Diagnosis. Adult female. Body elongate (approximately 4 times longer than wide); anterior margin of propodosoma without projections. All dorsal setae inserted on tubercles except h 1–2; setal pair c 1 inserted on single central tubercle. Dorsal setae v 2, sc 1, sc 2, c 1, c 3, d 1, d 3, e 3, f 2, f 3, h 1, h 2 present. Most dorsal setae thick, strongly barbed, except sc 1 sometimes elongate; setae h 1 minute, barbed; h 2 fine, elongate with minute club. Venter finely plicate; setae 1 a, 1 b, 2 b, 2 c, 3 a, 3 b, 4 a 1, 4a2, 4b, ag 1, g 1, g 2, ps 1, ps 2 present. Setae 1 a, 1 b, 4 a 1–2 elongate, extremely fine distally. Palps 3 -segmented, with setal formula 0, 2, 0(2); palp tarsus with two eupathidia. Leg chaetotaxy ( Table 1 View TABLE 1 ): no setae are added to femora, genua or tibiae during development; ge I – IV are nude in all stages; tr I – IV with one seta, v’. Seta v’ on tr IV is the only addition to the female (i.e. female leg chaetome matches deutonymph except v’ tr IV). Male has the same leg chaetotaxy as female except for the addition of a solenidion (ω ’) to ta I – IV (3 known only for G. tuberculatus ).

Immatures. Larva (known only for G. tuberculatus ) with posterior opisthosomal setae e 3, f 3, h 1 minute. Protonymph with posterior opisthosomal setae f 3, h 1 minute; setae e 3 minute ( G. gersonus ) or similar to other dorsal setae ( G. tuberculatus ). Deutonymph with posterior opisthosomal setae h 1 minute; setae f 3 minute ( G. gersonus ) or similar to other dorsal setae ( G. tuberculatus ). Seta v’ is added to tr I – III in deutonymph and to tr IV in adult. The leg chaetotaxies of the larva and protonymph are identical to those found on Cyperacarus gen. nov. ( Table 1 View TABLE 1 ).

continued next page Remarks. Gahniacarus gen. nov. can be separated from Cyperacarus gen. nov. by the presence of dorsal opisthosomal setae f 3 (absent in Cyperacarus ), and by the size of setae d 1, which is similar in size to the other dorsal setae in Gahniacarus , but minute in Cyperacarus . The two new genera, Gahniacarus and Cyperacarus , have dorsal opisthosomal setae c 1 present, dorsal opisthosomal setae e 1 absent and nude ge I–IV. In comparison, the two previously known tenuipalpid genera associated with Cyperaceae in Australia possess the following characters: dorsal opisthosomal setae c 1 absent, dorsal opisthosomal setae e 1 present, ge I–IV Acaricis 2 - 2 - 1 -0, Prolixus 2 - 1 - 0-0. See Table 2 View TABLE 2 for further morphological differences.

Etymology. This genus is named for the genus of plant on which it was collected, Gahnia J.R.Forst. & G.Forst. ( Cyperaceae ).

TABLE 1. Ontogenetic additions of setae for Gahniacarus (G) (G. tuberculatus and G. gersonus), Cyperacarus (C) (C. naomae and C. foliatus), Prolixus (P) (P. forsteri (Pf) and P. corruginus (Pc )), and Acaricis (A) (A. plana and A. danutae). Setae (Roman) and solenidia (Greek) are listed opposite the instar in which they first appear. The tarsal setae p’ - p ” are eupathidia. Ontogenetic stages are abbreviated as follows: deutonymph DN and protonymph PN.

  Coxa Tro. Femur Genu Tibia Tarsus
Leg I            
Larva—G/C P/A 1b - d v ʹ bv ʹ d d l ʹ l ʹ v ʹ v ʹʹʹ u ʹ u ʹ p ʹ p ʹ ft ʹ ωʹʹ
PN—G/C P/A - - - - - - - - - - ft ʹ tc ʹ tc ʹ
DN—G C Pf [Pc] A - - - - v ʹ - v ʹ [-] v ʹ - - l ʹ l ʹ - - - l ʹ - - - - - - - -
Female—G/C/A P - - - - - - - l ʹ - - - -
Male—G/A C Pf [Pc] - - - - v ʹ - [v ʹ] - l ʹ - - - l ʹ - - - ω ω ω
Leg II            
Larva—G/C Pf [Pc] A - - - - - - d v ʹ bv ʹ d v ʹ bv ʹ d v ʹ bv ʹ - - [d ʹ] d d l ʹ l ʹ v ʹ v ʹ d l ʹ l ʹ v ʹ v ʹ d l ʹ l ʹ v ʹ v ʹ u ʹ u ʹ p ʹ p ʹ ft ʹ ωʹʹ u ʹ u ʹ p ʹ p ʹ ft ʹ ωʹʹ u ʹ u ʹ p ʹ p ʹ ft ʹ ωʹʹ
PN—G/C P/A 2c 2c - - - - - - - - ft ʹ tc ʹ tc ʹ
DN—G C P A 2b 2b 2b 2b v ʹ - - v ʹ - - l ʹ l ʹ - - l ʹ l ʹ - - - - - - - -
Female—G/C/A Pf [Pc] - - - v ʹ [-] - - - - - - - -
Male—G/C/A P - - - v ʹ - - - l ʹ - - ω ω