Amphialycus (Orthacarus) oblongus (Halbert, 1920)

Uusitalo, Matti, Ueckermann, Edward A. & Theron, Pieter D., 2020, A review of the family Alycidae (Acari, Acariformes) from South Africa, Zootaxa 4858 (3), pp. 301-340 : 321-323

publication ID	https://doi.org/ 10.11646/zootaxa.4858.3.1
publication LSID	lsid:zoobank.org:pub:7BA52F1C-4084-4915-A7D9-8DA99379086B
DOI	https://doi.org/10.5281/zenodo.4412395
persistent identifier	https://treatment.plazi.org/id/AC6C87BA-C470-EB7A-FF1C-61601112D61E
treatment provided by	Plazi
scientific name	Amphialycus (Orthacarus) oblongus (Halbert, 1920)
status

Treatment

( Figs. 76–89 View FIGURES 76−83 View FIGURES 84−89 )

Alicus oblongus Halbert, 1920: 140 , pl. 23, figs. 23a–c, erroneous orthography of Alycus C.L. Koch ; holotype from Malahide , Ireland, from orange lichen zone at NMI ( National Museum of Ireland) .

Pachygnathus oblongus: Thor & Willmann 1941: 138 ; Baker & Bayliss 2005: 288.

Amphialycus (Orthacarus) oblongus: Uusitalo 2010: 58 , figs. 82–87.

Alycus? roseus Womersley, 1944: 139 .

Orthacarus tremli Zachvatkin, 1949: 292 , figs. 1–5.

Description. Dorsum ( Figs. 76, 77 View FIGURES 76−83 ). Length 300–500 μm; neotrichous setal pattern dorsally and on ventral side; naso absent, prodorsal setae vi, sce and exp sparsely ciliated (reduced), sensilla ve and sci filamentous, distances between counterparts of setae vi and anterior bothridial sensilla ve less than distance between setae in.

Venter ( Figs. 77–79 View FIGURES 76−83 ). Genital valves each with 12–18 genital setae; anal valves terminally with 7–8 setae.

Gnathosoma ( Figs. 76, 80–82 View FIGURES 76−83 ). Pair of smooth cheliceral setae abaxially; rutella widening to apical lobes and a pointed process, one pair of adoral setae; distally narrow palpal tarsi with four basally fused, microtrichous eupathids.

Legs ( Fig 83 View FIGURES 76−83 ). Claw-like empodium multisetulate; solenidial formula for tarsi, tibiae, genua and femora on legs I, II, III and IV, respectively: 2-1-0-0, 2-2-2-0, 3-2-0-1, 1-0-0-0.

Larva (n=5, Figs. 88, 89 View FIGURES 84−89 )

Dorsum. Length 200 μm; holotrichous; sensilla ve and sci filamentous.

Venter. Holotrichous; genital valves absent.

Gnathosoma . One pair of fused palpal eupathids.

Legs. Solenidial formula for tarsi, tibiae, genua and femora on legs I, II and III, respectively: 1-1-0, 2-2-2, 3- 2-0, 1-0-0.

Other life stages:

Protonymph (n=6, Fig. 87 View FIGURES 84−89 ), 1 genital seta per valve.

Deutonymph (n=8, Fig. 86 View FIGURES 84−89 ), 4 genital setae per valve.

Tritonymph (n=6, Fig. 85 View FIGURES 84−89 ), 11 genital setae per valve.

Adult male (n=9, Fig. 84 View FIGURES 84−89 ), 12–18 genital setae setae, 7 pairs of eugenital setae.

Adult female (n=18, Figs. 78, 79 View FIGURES 76−83 ), 12–18 genital setae per valve, 1 pair of eugenital setae.

Material examined. Eighteen females, 9 males, 6 tritonymphs, 8 deutonymphs, 6 protonymphs and 5 larvae from Themeda triandra -biotope, Potchefstroom, NORTH-WEST PROVINCE, 25 March 1969, P.D. Theron. Deposited at ARC-Plant Health and Protection, Pretoria, South Africa .

Differential diagnosis. This species easily differs from other neotrichous species of Amphialycus by having character states typical to the subgenus Orthacarus : without naso, prodorsal setae reduced in size, counterparts of setae vi inserted exceptionally closely to each other, basally fused palpal eupathids, short and bent legs and caudal anus ( Figs. 76, 77, 82 View FIGURES 76−83 ). From other (still undescribed) species of the subgenus Orthacarus , this species differs by having both pairs of prodorsal sensilla (ve and sci) filamentous, abaxially inserted cheliceral setae and a typical solenidial pattern.