Ameroseius Berlese, 1904,

Masan, Peter, 2017, A revision of the family Ameroseiidae (Acari, Mesostigmata), with some data on Slovak fauna, ZooKeys 704, pp. 1-228: 1

publication ID

http://dx.doi.org/10.3897/zookeys.704.13304

publication LSID

lsid:zoobank.org:pub:111A101E-7405-4C40-8F51-693957A64D97

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http://treatment.plazi.org/id/A7206E6F-D71F-01C0-2035-035F5D3606C5

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ZooKeys by Pensoft

scientific name

Ameroseius Berlese, 1904
status

 

Genus Ameroseius Berlese, 1904 

Ameroseius  Berlese, 1904: 258. Type species: Seius echinatus  C. L. Koch, 1839 (= Acarus corbicula  Sowerby, 1806), by original designation. Synonymy by Vitzthum (1942).

Cornubia  Turk, 1943: 858. Type species: Cornubia ornata  Turk, 1943 (= Acarus corbicula  Sowerby, 1806), by original designation. Synonymy by Turk (1953).

Ameroseius  . - Evans 1963a: 230.

Diagnosis (adults).

Dorsal shield strongly sclerotised and coarsely sculptured, rugose, callous or ornamented with a series of depressions or interconnecting ridges, and normally with 29 pairs of setae (in magnisetosus  group, the shield delicately reticulated and with only 26-27 pairs of setae). Dorsal setae similar or differently formed, variously modified, thickened and lengthened, lanceolate or oblanceolate to slightly claviform (plumose, pilose, serrate or spinate on surface), rarely short, smooth and needle-like, and not sexually dimorphic (except fungicola  group). In female, st1 and st2 on sternal shield, st3 on small pseudo-metasternal platelets or soft integument and st4 on soft integument; ventral shields usually well reticulate on surface; genital poroids outside the epigynal shield. Anal shield having three circum-anal setae in female, only rarely bearing an extra pair of opisthogastric setae (JV3) close to its anterolateral edges; male with expanded ventrianal shield having usually three pairs of opisthogastric setae: JV2, JV3, ZV2 (in Ameroseius dendrovagans  , the shield less expanded to capture only two pairs of opisthogastric setae: JV2, JV3). Peritrematal shields with anterior ends connected to dorsal shield. Opisthogastric soft integument with five or six pairs of setae in female (JV4 sometimes absent); male never with JV4 developed, with five pairs of opisthogastric setae (JV1-JV3, JV5, ZV2). Corniculi normally horn-like, relatively broad and parallel, with splitted and pointed apex (in fungicola  group, corniculi membranous, hyaline, undivided and directed laterally). In female, fixed digit of chelicera normally tridentate on proximal masticatory area (bidentate in fungicola  group); movable digit edentate, at most with subapical denticle, and provided with short spermatodactyl in male. Epistome usually subtriangular, with curved apex, with smooth or denticulate anterior margin. Palptarsal apotele usually three-tined. Genu III and tibiae III–IV with two anterolateral and one posterolateral setae. Tarsi I–IV each with well developed empodium and claws. Insemination apparatus with barely discernible structures.

Remarks.

Ameroseius  is the most speciose genus of Ameroseiidae  . In this paper, it comprises 50 valid species having their type specimens reported from almost all continents: 13 species each from Africa and Asia, 12 species from Europe, five species each from North and South America, and two species from Australia. In Slovakia, this genus is represented by 13 recorded species. Mites of this genus are apparently fungivorous living in a wide variety of habitats such as wood substrates, wood-destroying fungi, decomposing plant material and humic soils. Most of them belong to highly specialised species, each adapted to a particular environment. There are species associated with bark beetle galleries, or wood-boring beetle galleries, in subcorticolous habitats, and feeding on a specific diet of ambrosia fungi, and phoretically active on xylophagous insects (mostly Cerambycidae  ). Some African species are phoretically associated with wasps and bees. In Slovakia, most species can be easily found on bracket fungi, especially on a lower fertile surface of the sporocarp (fruiting body).

Some authors ( Bregetova 1977, Evans and Till 1979) attempted to clarify the general concept of Ameroseius  by removing some species that obviously belong to other genera ( Ameroseiella  , Kleemannia  ). In this paper I refine the concept of the genus further, by establishing a new genus based on Ameroseius michaelangeli  Moraza, 2006, removing all species that belong to Kleemannia  and Asperolaelaps  and that were previously placed in Ameroseius  , and introducing two species groups based on Ameroseius magnisetosus  and Ameroseius fungicola  (see below). The process of clarifying the genus should continue, especially with regard to some characters inconsistent with Ameroseius  in the species from Africa described by Elsen (1973). His African species show some atypical characters for Ameroseius  , for example: (1) cheliceral digits distally curved, fixed digit with five proximal denticles in Amerosieus megatritosternum  , or with only one very robust medial tooth in Ameroseius bembix  , Ameroseius gabonensis  and Ameroseius leclercqi  ; (2) peritremes and peritrematal shields densely spinate, especially the outer posterior margin of peritrematal shields with large spines; (3) dorsal shield setae relatively short and stout, brush-shaped; (4) anterior margin of epistome deeply dentate; (5) setae JV5 similar to those on dorsal shield, brush-shaped; (6) strong sclerotic incrustation of soft integument on opisthogastric surface. Generally, the border between Ameroseius  and Neocypholaelaps  is weak, based on a few diagnostic features of gnathosoma. The species of Elsen (1973) appear to have an intermediate position between these two genera because, in some respects, they exhibit certain similarities with Neocypholaelaps  , whose members are also associated with bees and wasps (form of cheliceral digits and dorsal setae, and additional sclerotization of soft integument).

There are three Asian Ameroseius  species ( denticulatus  , magnisetosus  and submagnisetosus  ) representing a specific group of closely related (if not identical) congeners characterised especially by a combination of the following character states: (1) dorsum with deficient chaetotaxy, having only 26-27 pairs of setae; (2) dorsal shield lacking coarse sculpture, with only delicate reticulate pattern; (3) in female, st3 on soft integument due to the absence of pseudo-metasternal platelets; (4) in male, st4 on soft integument, outside the sternogenital shield (5) five pairs of opisthogastric setae present (JV4 absent), of which JV3 on (ventri)anal shield, and JV5 similar to other setae on ventral surface. The above enumerated species are here referred to as the Ameroseius magnisetosus  group. Unfortunately, I have examined no representative of this peculiar group to confirm reduced number of dorsal setae and other features as stated above.

There is a combination of diagnostic characters to recognise the newly designated Ameroseius fungicola  species group, namely (1) fixed digit of chelicera bidentate, the two teeth small and similar in size; (2) corniculi unsclerotised, membranous, hyaline, medially curved, with tapered and undivided apex directed anterolaterally; (3) conspicuous dimorphism of dorsal chaetotaxy: in males, centrally situated setae strongly reduced in length when compared with those in females; (4) male with anal shield bearing only three circum-anal setae; (5) setae z5 minute; (6) absence of postgenital slit-like sclerites; (7) anus close to anterior margin of anal shield; (8) cheliceral digits relatively small; (9) legs I relatively short and thick (especially tarsi); (10) in male, legs I and palptrochanters with some setae thicker and spiniform when compared with those in female; and (11) empodium and claws of tarsi I–IV well developed, relativelly large; (12) in males, tarsal claws of legs II apparently larger than in other legs. This group contains only two described species ( fungicola  , callosus  ), and it can be characterised by several peculiar characters (see points 1-4, 12), unique or rarely expressed in Ameroseiidae  . From a phylogenetic point of view, presence of these characters might support the idea of the justified existence of a separate ameroseiid taxon based on A. fungicola  and A. callosus  .

Narita et al. (2015) constituted a separate species group for 21 species of Ameroseius  , referred to as the sculptilis  group, with the following character states: (1) dorsal shield with ridges and pit-like depressions combined with a reticulate pattern of simple lines; (2) dorsal shield with 29 pairs of mostly stout and serrate setae; (3) posterior ventral surface with five or six pairs of opisthogastric setae; (4) ventrianal shield with 0-2 pairs of setae (in addition to three circum-anal setae). However, all these character-state arguments are weak, based on greatly variant and vague features, and not suitable for correct separation of the species, even at least at the level of Ameroseius  / Kleemannia  species as understood in this paper. So, I here did not follow Narita et al. (2015) in their concept of sculptilis  as a separate and reasonably derived species group of Ameroseius  .

Key to species of Ameroseius  occurring in Europe (females)

European species of Ameroseius  can be identified using keys from Westerboer and Bernhard (1963), Karg (1971a, 1993) and Bregetova (1977). In their keys, these authors included six, eight or nine species, respectively. A smaller part of the world species of Ameroseius  (17 species) can be identified using keys of Narita et al. (2015), but better portion of congeners should be exclusively identified using the primary species descriptions. A new key presented here contains 13 species considered to be of the European origin, including recently described species ( Ameroseius callosus  , Ameroseius fungicola  and Ameroseius lehtineni  ), and a new species described in this study.

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Mesostigmata

Family

Ameroseiidae

Loc

Ameroseius Berlese, 1904

Masan, Peter 2017
2017
Loc

Cornubia

Turk 1943
1943
Loc

Cornubia ornata

Turk 1943
1943
Loc

Ameroseius

Berlese 1904
1904
Loc

Ameroseius

Berlese 1904
1904
Loc

Seius echinatus

Agassiz 1845
1845