The order Mesostigmata includes 180 families, 869 genera, 11,408 species worldwide (Beaulieu et al., 2011), with 307 species of 111 genera and 33 families recorded in Korea (NIBR, 2021). The genus Holostaspella, which belongs to the family Macrochelidae, has over 30 species worldwide (Hartini and Takaku, 2010), but only two species, H. ornata (Berlese, 1904); H. scatophilaTakaku, 1994 have been recorded in Korea (Lim and Lee, 2005;Hartini and Takaku, 2010;Keum et al., 2016). Most of Macrochelid mites are associated with carrion insects (Krantz, 1962a;Takaku, 1994;Hartini and Takaku, 2003;Arriaga-Jimenez et al., 2014;Knee, 2017), however, some species of Holostaspella has been observed from leaflitters, pasture, and fungus (Krantz, 1967;Halliday, 1988, 2000;Plumari, 2010;Takaku et al., 2012;Özbek, 2017).

The genus Lasioseius, which belongs to the family Blattisociidae, includes 206 species worldwide, with five species, (L. furcisetus Athias-Henriot, 1959; L. porulosus De Leon, 1963; L. sugawarai Ehara, 1964; L. tomokoae Ishikawa, 1969; L. yousefi Athias-Hentiot, 1959) reported in Korea (Lee and Lee, 1998;Kontschán et al., 2015;Faraji, 2021). Among those Korean species, L. lasiodactyli Ishikawa, 1969 was synonymized with L. youcefi Athias-Henriot, 1959 by Christian and Karg (2006). Although this genus is typically free-living, they have also been found in grasslands, upper soil, crop fields, and even animal nests (Christian and Karg, 2006). In this study, we report two new record species, H. crenulataKrantz, 1967, and L. floridensisBerlese, 1916, along with diagnoses and illustrations. Additionally, key to the Korean species of each genus is also provided.

Material and Methods

The samples were separated from the leaf-litters and insectrearing cage by using Berlese-Tullgren funnel trap (60 W, 48 h). Mites were cleared in lactic acid with 70°C of dry bath and mounted in PVC medium (Downs, 1943). The identifications and capturing digital images of the specimens were performed with Olympus BX53 DIC (differential interference contrast) microscope with Olympus DP27 camera and Cellsens standard 3.1 software. Line drawing plates were prepared with Adobe Illustrator CC 22.0.1 program based on digital images. The length of all shields was measured from the anterior-median peaks to the posterior-median peaks, and the width was taken from the widest margin of the shields, respectively. The length of the legs was measured from coxa to the apex of the tarsus, excluding the pre-tarsus. The nomenclature used for the dorsal chaetotaxy follows Lindquist and Evans (1965), the other morphological terms follow Evans (1963), Evans and Till (1979), and Krantz and Walter (2009).

The specimens examined are deposited at the National Institute of Biological Resources (NIBR) and the Insect Biosystematics Lab., Seoul National University (SNU), Seoul, Republic of Korea.

Systematic Accounts

Family Macrochelidae Vitzthum, 1930

Genus HolostaspellaBerlese, 1903

HolostaspellaBerlese, 1903: 241.

PrholaspinaBerlese, 1918: 175.

AreolaspisTrägårdh, 1952: 61.

Holostaspella crenulataKrantz, 1967 톱니무늬파리응애(신 칭) (Figs. 1-3)

Holostaspella crenulataKrantz, 1967: 151.

Diagnosis. Female. Body orange-colored, circular shape, 527-641 μm in length, 495-504 μm in width. Dorsal shield without anterior projection, bearing 28 pairs of slightly pectinated setae (41-63 μm) (Fig. 1A). Sternal setae smooth acicular-liked, moderate length. Ventrianal shield oval-shaped with four pairs of acicular setae, nine to ten bipectinated setae on ventral integument (Fig. 1B). Thumb and hook-liked projections on each segment of leg II, most leg setae pectinated (Fig. 3D). In gnathosoma, four pairs of simple gnathosomal setae and five rows of deutosternal grooves with numerous denticles (Fig. 3B). Tripartited epistome with folked medial projection (Fig. 3A). Fixed digit of chelicera with simple pillus dentilis, movable digit of chelicera bidentate, dagger-shaped cheliceral seta, tassel-liked arthropodial brush present (Fig. 1C). Surface of all shields covered with punctured thick ridges (Figs. 2A, B).

Male. Body size 438 μm in length, 373 μm in width. In ventral, holoventral shield covered whole ventral portion, surface of shield covered with same reticulations as in female (Figs. 2C, D). Genital orifice located on anterior margin of shield, seven pairs of simple setae bearing on shield excluding para and post anal setae (Fig. 1D). Spermatodactyl curved backward (sickle-shaped) (73-77 μm) (Fig. 3C). In legs, most setae acicular-shaped except for some dorsum setae and femur-tibia II with projections. Other morphological features the same as in females.

Specimens examined. 12♀♀, 1♂, Hangye-ri 854, Bukmyeon, Inje-gun, Gangwon-do, Korea, 24. viii. 2020, from humid leaf litter, leg. Jaeseok Oh.

Distributions. Yap island (Micronesia) (Krantz, 1967); Australia (Halliday, 1988); Philippines (Takaku et al., 2012); Korea.

Remarks.Halliday (1988) described that all of the male’s legs setae are smooth and pointed. However, we observed some slightly modified setae in our male specimen. femur I: pd1, pd2; trochanter II: ad; femur II: ad1, ad2, pd1, pd2, and pv1 (blunted); genu II: ad1, ad2, pd1, and pd2; tibia II: ad1, ad2, pd1, and pd2; genu III: ad1, ad2, pd1, and pd2; tibia III: ad, pd1, and pd2; tarsus III: ad3, ad4, pd3, and pd4; trochanter IV: ad; femur IV: al, ad1, and pd; genu IV: al, ad1, ad2, pd1, and pd2; tibia IV: al, ad1, ad2, pd, and pl; tarsus IV: ad3, ad4, pd3, and pd4.

Key to species of the genus Holostaspella in Korea based on the female

Family Blattisociidae Garman, 1948

Genus LasioseiusBerlese, 1916

LasioseiusBerlese 1916: 33.

AceoseiusSellnick, 1941: 149.

BorinquolaelapsFox, 1946: 450.

HyattellaKrantz, 1962b: 6.

GnorimusChaudhri, 1975: 100

IndiraseiusDaneshvar, 1987: 32.

NeolaspinaHalliday, 1995: 213.

Lasioseius floridensisBerlese, 1916 가슴선화살응애(신칭) (Figs. 4-5)

Lasioseius (Zercoseius) penicilliger var. floridensisBerlese 1916: 44.

Lasioseius arboreusChant, 1963: 291.

Lasioseius fimetorumKarg, 1971: 248.

Diagnosis. Female. Body pale-yellow colored, rectangular shape, 407 μm in length, 220 μm in width. Dorsal shield not covered whole dorsum, surface of the shield covered with scalelike reticulation. Dorsal shield bearing 36 pairs of tricarinate and pointed-pectinated setae except acicular-shaped z1, s2, r2, and J5. Marginal setae r2-r4 bearing on dorsal shield, r5, r6, and R1-R6 situated in the lateral cuticle (Figs. 4A, 5A). Surface of sternal and genital shield covered with dotted patterns, anteromedial part of sternal shield with irregular crack. Ventrianal shield with four pairs of simple setae, surface of shield covered with distinctive lineate reticulations (Figs. 4B, 5B). In gnathosoma, seven rows of deutosternal grooves with numerous denticles (Fig. 5C). Branched epistome with a pair of serrated lateral branches and slightly forked median projection (Fig. 5D).

Specimens examined. 1♀, Songcheon-dong, Andong-si, Gyeongsangbuk-do, Korea, 03. vii. 2019, from dried sawdust bedding in Dorcus rectus rearing cage, leg. Jaeseok Oh & Sehyeon Bang.

Distribution. Brazil, Canada, Germany, Mexico, and the U.S.A. (Britto et al., 2011); Korea.

Remarks.Christian and Karg (2006) listed L. floridensis as one of the species under inquiry within the genus Lasioseius. Subsequently, Britto et al. (2011) reestablished L. floridensis as a valid species, providing a detailed description and several plates illustrating both sexes.

Key to species of the genus Lasioseius in Korea based on the female