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

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 h1–2; setal pair c1 inserted on single central tubercle. Dorsal setae v2, sc1, sc2, c1, c3, d1, d3, e3, f2, f3, h1, h2 present. Most dorsal setae thick, strongly barbed, except sc1 sometimes elongate; setae h1 minute, barbed; h2 fine, elongate with minute club. Venter finely plicate; setae 1a, 1b, 2b, 2c, 3a, 3b, 4a1, 4a2, 4b, ag1, g1, g2, ps1, ps2 present. Setae 1a, 1b, 4a1–2 elongate, extremely fine distally. Palps 3-segmented, with setal formula 0, 2, 0(2); palp tarsus with two eupathidia. Leg chaetotaxy ( 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 e3, f3, h1 minute. Protonymph with posterior opisthosomal setae f3, h1 minute; setae e3 minute ( G. gersonus ) or similar to other dorsal setae ( G. tuberculatus ). Deutonymph with posterior opisthosomal setae h1 minute; setae f3 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 ).

continued next page Remarks. Gahniacarus gen. nov. can be separated from Cyperacarus gen. nov. by the presence of dorsal opisthosomal setae f3 (absent in Cyperacarus ), and by the size of setae d1, 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 c1 present, dorsal opisthosomal setae e1 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 c1 absent, dorsal opisthosomal setae e1 present, ge I–IV Acaricis 2-2-1-0, Prolixus 2-1- 0-0. See 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) .

Tables

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