A review of the family Alycidae (Acari, Acariformes) from South Africa
Author
Uusitalo, Matti
Zoological Museum, Centre for Biodiversity, University of Turku, FIN- 20014 Turku, Finland
Author
Ueckermann, Edward A.
0000-0003-4213-4309
Unit for Environmental Sciences and Management, Potchefstroom Campus, North-West University, Private Bag X 6001, Potchefstroom, 2520, South Africa & https: // orcid. org / 0000 - 0003 - 4213 - 4309
Author
Theron, Pieter D.
0000-0003-4213-4309
Unit for Environmental Sciences and Management, Potchefstroom Campus, North-West University, Private Bag X 6001, Potchefstroom, 2520, South Africa & https: // orcid. org / 0000 - 0003 - 4213 - 4309
text
Zootaxa
2020
2020-10-01
4858
3
301
340
journal article
8277
10.11646/zootaxa.4858.3.1
f8abea37-7992-482c-8a49-982d08cf9f66
1175-5326
4412321
7BA52F1C-4084-4915-A7D9-8DA99379086B
Amphialycus (Orthacarus) oblongus
(Halbert, 1920)
(
Figs. 76–89
)
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
). 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
). Genital valves each with 12–18 genital setae; anal valves terminally with 7–8 setae.
Gnathosoma
(
Figs. 76, 80–82
). 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
). 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
)
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
), 1 genital seta per valve.
Deutonymph (n=8,
Fig. 86
), 4 genital setae per valve.
Tritonymph (n=6,
Fig. 85
), 11 genital setae per valve.
Adult male (n=9,
Fig. 84
), 12–18 genital setae setae, 7 pairs of eugenital setae.
Adult female (n=18,
Figs. 78, 79
), 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
.
FIGURES 76−83.
Amphialycus (Orthacarus) oblongus
(Halbert)
. 76—Prodorsum, naso missing, distance between counterparts of setae
vi
and sensilla
ve
smaller than between setae
in
, setae
vi
,
sce
and
exp
reduced; 77—Dorsal habitus, neotrichy; 78—Ventral habitus, 17 genital setae per valve, 8 anal setae per valve (cf. Fig. 77); 79—Genital valve of female, 16–18 genital setae, 1 pair of eugenital setae; 80—Subcapitulum, 1 pair of adorals; 81—Rutellum; 82—Palp, tarsus with 4 barbed and basally fused eupathids; 83—2 slightly bent claws and densely setulated, claw-like empodium.
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
). 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.