Hattena Domrow, 1963

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

Genus Hattena Domrow, 1963

Hattena Domrow, 1963: 202. Type species: Hattena erosa Domrow, 1963, by monotypy.

Edbarellus Manson, 1974: 115. Type species: Edbarellus tonganus Manson, 1974, by original designation. Synonymy by Halliday (1997).

Diagnosis (adults).

In female, dorsal shield lightly sclerotised, weakly reticulated or unornamented, often irregular in outlines (with 1-3 pairs of lateral incisions), narrowed and not covering whole dorsal surface; dorsal setae short, needle-shaped, similar in length, inserted on dorsal shield (18-25 pairs) and soft integument beside the dorsal shield (3-20 pairs); sometimes dorsolateral and ventrolateral soft integument hypertrichous, with up to 35 setal pairs (non-hypertrichous forms usually with standard number of 28-29 pairs of dorsal setae on dorsal shield and soft integument). Male often with some dorsal shield setae (8-10 pairs) conspicuous, thickened, extremely long and much longer than some of the shortest ones; with slightly expanded dorsal shield capturing some additional pairs of setae inserted on soft integument in female. Female with st1 on weakly sclerotised and inconspicuous sternal shield; setae st2 on sternal shield, small sternal shield fragments or soft integument; setae st3 associated with small endopodal platelets II-III or on soft integument; and st4 on soft integument; sternal shield usually markedly reduced; epigynal shield widely separated from anal shield, with parallel lateral margins, and usually with genital poroids on its surface. Female with anal shield, male with anal shield or ventrianal shield bearing 1-3 pairs of opisthogastric setae. Peritrematal shields or peritremes with anterior ends free and not connected to dorsal shield. Opisthogastric soft integument with five to six pairs of setae (JV3 usually absent in male). Corniculi slender and pointed, with undivided apex. Fixed digit of female chelicera usually edentate, with bifid terminal hook, sometimes with one or two medial denticles; movable digit edentate, with strongly developed terminal hook; pilus dentilis usually not modified into a membranous structure; male with well elongated spermatodactyl directed downward. Palptarsal apotele two-tined. Genu III and tibia III with two anterolateral and one posterolateral setae; tibia IV with two anterolateral and two posterolateral setae. Tarsi I-IV each with empodium and slightly to fully reduced claws. Insemination apparatus with spermathecal ducts unfused.

Remarks.

Generally, the genus Hattena as a whole shows relatively high diversity in external morphology, and it represents a conglomerate of morphologically heterogeneous species. The following character states were used to separate the Hattena species into five species groups (see the identification key below): (1) expression of z6 (absent in Hattena cometis group); (2) expression of J3 (present in Hattena panopla group); (3) position of Z5 (on soft integument in Hattena panopla group); (4) setation of soft integument (hypertrichy in Hattena cometis and Hattena erosa groups); (5) form of posterior part of dorsal shield (incised in Hattena dalyi and Hattena panopla groups); (6) sexual dimorphism of dorsal shield setae (markedly developed in Hattena cometis group); (7) position of genital poroids (outside the epigynal shield in Hattena erosa and Hattena senaria groups); (8) sexual dimorphism of anal shield (absent in Hattena dalyi group); (9) character of tritosternal laciniae (fused for most of their length in Hattena panopla group); (10) setation of ventrianal shield in male (with a pair of opisthogastric setae in Hattena panopla group and three pairs in Hattena cometis group); (11) setation of palptrochanter (with only one ventral seta in Hattena cometis and Hattena erosa groups); (12) legs IV in male (spurred in Hattena cometis group).

In this genus, the dorsal shield of males is more expanded than in females, thus bearing up to ten pairs of the setae that in females are inserted on the soft integument. Hattena cometis , Hattena erosa and Hattena floricola have polytrichous soft integument on dorso- and ventrolateral idiosomal surface. Polytrichy has been mentioned in the literature only for females; it was not reported in the descriptions of males of H. cometis and H. floricola . Therefore, the polytrichy of male soft integument may be neglected by Domrow (1979) and Halliday (1997), if not considerably reduced or absent.

It is remarkable that there is an additional setal pair of the J-series (J3) expressed on the dorsal shield in Hattena panopla and Hattena tongana . This seta is also present in Neocypholaelaps novaehollandiae .

Hattena clemmys was not included in the species group classification scheme introduced in this paper because there are several evidences that it is incorrectly placed in this genus: (1) dorsal shield divided into six fragments; (2) sternal shield not strongly reduced but without sternal setae and poroids; (3) setae st5 on soft integument, off the epigynal shield; (4) peritremes strongly abbreviated; (5) movable digit of chelicera with elongate and fringed process; (6) palptarsal apotele three-tined; (7) tarsus of legs I-IV with normally developed claws on empodium. It was placed in Hattena because of the extent of the dorsal shield and the number of dorsal shield setae, but it probably represents a new genus. Therefore the above mentioned specific characters of H. clemmys are not included in the diagnosis of Hattena .

The genus Hattena now comprises ten species distributed in the tropical areas of the Old and New Worlds (Australia, Ecuador, Kenya, Malaysia, Pacific Ocean Region, Papua New Guinea, Taiwan and Vietnam), in association with flowers and flower-visiting animals (birds, bees and bats). Hattena dalyi and Hattena tonganus are known to be phoretically associated with the Euroepean honey bee, Apis mellifera (from tropics).

Partial keys to the known species of Hattena may be found only in Halliday (1997), for four species reported from Australia ( Hattena cometis , Hattena floricola , Hattena incisa and Hattena panopla ), and in Faraji and Cornejo (2006), based on six species known up to that time ( Hattena cometis , Hattena erosa , Hattena floricola , Hattena incisa , Hattena panopla and Hattena rhizophorae ). A new and more complete key to the genus is needed to include other species, namely Hattena dalyi (transferred from Afrocypholaelaps by Klimov et al. in 2016) and Hattena senaria comb. n.

Key to species group of Hattena (adults)

1	Female idiosoma hypotrichous or holotrichous, with at most 30 pairs of dorsal and six pairs of opisthogastric setae (in addition to the sternal and circum-anal setae); sexual dimorphism of dorsal shield setae not well developed: female and male (when described) with short, pointed and subequal setae; male with anal shield or small ventrianal shield bearing at most one pair of opisthogastric setae (JV2); palptrochanter with two ventral setae; male femur IV not spurred	2
-	Female idiosoma polytrichous, with 34-40 pairs of dorsal and 8-15 pairs of opisthogastric setae; sexual dimorphism of dorsal shield setae well developed: female with short, pointed and subequal setae, male with some dorsal setae (8-10 pairs) conspicuously thickened and lengthened; male with expanded ventrianal shield bearing three pairs of opisthogastric setae (JV1, JV2, ZV2); palptrochanter with one ventral seta; male femur IV with ventral spur	4
2	Dorsal shield without posterolateral incisions; genital poroids on soft integument close to posterolateral margins of epigynal shield, the shield with moderate posterior expansion	Hattena senaria group ( Hattena senaria )
-	Dorsal shield with 1-3 pairs of posterolateral incisions; genital poroids on epigynal shield, the shield with parallel lateral margins, unexpanded posteriorly	3
3	Dorsocentral J-series with three pairs of setae (J2-J4); in female, Z5 on soft integument behind posterior margin of dorsal shield; male ventrianal shield bearing a pair of opisthogastric setae (in addition to the circum-anal setae) and a wide incision on anterior margin; laciniae of tritosternum longer, free for most of their length	Hattena panopla group ( Hattena panopla , Hattena tongana )
-	Dorsocentral J-series with two pairs of setae (J2, J4; J3 absent); in female, Z5 on dorsal shield; male anal shield bearing only circum-anal setae, anterior magin of the shield without incision; laciniae of tritosternum shorter, fused for most of their length	Hattena dalyi group ( Hattena dalyi , Hattena incisa , Hattena rhizophorae )
4	Setae z6 present; genital poroids on soft integument close to posterolateral margins of epigynal shield	Hattena erosa group ( Hattena erosa )
-	Setae z6 absent; genital poroids on epigynal shield	Hattena cometis group ( Hattena cometis , Hattena floricola )