Hannemania aiuabensis Bassini-Silva, Jacinavicius and Welbourn, 2021

Bassini-Silva, Ricardo, Huang-Bastos, Matheus, Morais, Drausio Honorio, Alcantara, Edna Paulino, Ávila, Robson Waldemar, Welbourn, Cal, Ochoa, Ron, Barros-Battesti, Darci Moraes & Jacinavicius, Fernando de Castro, 2021, A new species of Hannemania Oudemans, 1911 (Trombidiformes: Leeuwenhoekiidae) from Brazil, Journal of Natural History 55 (19 - 20), pp. 1277-1287 : 1280-1284

Hannemania aiuabensis Bassini-Silva, Jacinavicius and Welbourn , n. sp.

( Figures 1–4 , Tables 1–4)

Diagnosis. Palpgenu with single nude seta; dorsal and lateral palptibial setae nude; ventral palptibial setae branched; adoral (cs) setae branched; eyes without ocular plate; pair of nude flagelliform trichobothria (si); middle of posterior margin of the prodorsal sclerite with a V-shaped projection; C row with 14 setae; D row with eight setae; E row with 10 setae; F row with three setae; 83 to 89 opisthosomal setae; 39 to 43 ventral opisthosomal setae; 9 to 10 σ on Ge I; famulus (Ε) on Ta I and II each distal to solenidion (ω).

Description. Larvae (holotype, 6 paratypes and 20 additional specimens). Gnathosoma – fPp = B/N/NNB/5B, with ω; odontus trifurcate; cheliceral blade with row of 10 to 12 outer distal teeth and a hook-shaped inner tooth; gnathobase with few punctuations, subcapitular setae (bs) and adoral setae (cs) branched ( Figure 1 (a,b)). Idiosoma – eyes 2/2, separate from prodorsal sclerite, posterior lens larger; without ocular plate, hexagonal prodorsal sclerite punctuated with nasus and lateral margins of prodorsal sclerite slightly concave, straight anterior and V-shaped projection in the middle of posterior margin ( Figure 2 ), with pair of nude flagelliform trichobothria (si), 6 branched normal setae [pair of ve (= AL), pair of vi (= AM) and pair of se (= PL)]; si> se> ve> vi. Opisthosoma ( Figure 3 (a, b)) with 83 to 89 setae, dorsal opisthosoma C row with 7 pairs of irregularly placed setae, D row with 4 pairs of setae, E row with 5 pairs of setae, F row with 3 pairs of setae, H row unrecognisable with 6 to 8 irregularly placed setae posterior to the F row, for total of 44 to 46 dorsal opisthosomal setae and 39 to 43 ventral opisthosomal setae (19 to 20 anterior and 20 to 23 posterior to anus). One pair of sternal setae (3a) between coxal fields III; anterior sternal setae (1a) located on the proximal end of coxal field I; sternal setae 2a absent. Legs – femora of legs I–III entire, each leg terminates with pair of claws and claw- like empodium, without onychotriches, coxal fields with few punctations; Leg I – two branched coxal field setae 1a and 1b (2B); trochanter 1B; femur 6B; genu 4B, 9 to 10 σ and a distal κ; tibia 8B, 2 φ and a distal κ; tarsus 25B, ω, Ε, dorsal eupathidium (ζ’) with a companion seta (z) and a subterminal eupathidium (ζ”), base of famulus (Ε) distal to solenidium (ω) ( Figure 4 (a)). Leg II – coxal field seta 2b (1B); trochanter 1B; femur 5B; genu 4B, σ; tibia 6B, 2 φ; tarsus 17B, ω, Ε and a subterminal eupathidium (ζ), base of Ε distal to ω ( Figure 4 (b)). Leg III – coxal field seta 3b (1B); trochanter 1B; femur 4B; genu 4B, σ; tibia 6B, φ; tarsus 16B ( Figure 4 (c)).

Differential diagnosis. Hannemania aiuabensis Bassini-Silva, Jacinavicius and Welbourn , n. sp. is closest to the group of species in the genus that have the adoral (cs) branched setae, odontus trifurcate and more than 3 σ on Ge I. These species are as follows: Hannemania anurae Welbourn and Loomis, 1970 ; H. bufonis Loomis and Welbourn, 1969 ; H. hegeneri Hyland, 1965 ; H. hylae ( Ewing, 1925) ; H. monticola Welbourn and Loomis, 1970 ; H. newsteadi Sambon, 1928 ; and H. saxicola Welbourn and Loomis, 1970 . However, the new species can be separated from all the above species, as it presents the palpgenu with nude seta, palptibia with nude dorsal and lateral setae and a branched ventral seta, and absence of onychotriches on the legs I–III. In addition, the species H. bufonis , H. hylae , H. monticola and H. newsteadi have ocular plates, unlike the new species which lacks ocular plates. Also, it can be separated from H. anurae by having the coxal field III unisetose (vs. bisetose), while the new species can be separated from H. hegeneri and H. saxicola by having one σ on Ge II and

III (vs. more than three σ on Ge II and III) and absence of the solenidia on Fe III (vs. its presence).

Type material. HOLOTYPE: larva ( IBSP 15446), Aiuaba municipality, Ceará state, Brazil (40° 08 ʹ 31” W, 06° 35 ʹ 35” S), 14 January 2018, ex Leptodactylus fuscus (Schneider) ( Anura : Leptodactylidae ), D. H. Morais coll. PARATYPES: 1 larva ( IBSP 15446), same data as the holotype; 2 larvae ( IBSP 15439), same data; 1 larva ( IBSP 15445), same data; 2 larvae ( IBSP 15447), same data.

Additional material examined. BRAZIL: 1 larva ( IBSP 15438), Aiuaba municipality, Ceará state, 14 January 2018, ex Physalaemus albifrons (Spix) ( Anura : Leptodactylidae ), D. H. Morais coll.; 2 larvae ( IBSP 15441), same data; 2 larvae ( IBSP 15442), same data; 2 larvae ( IBSP 15443), same data; 2 larvae ( IBSP 15444), same data; 4 larvae ( IBSP 15448), same locality and date, ex Leptodactylus macrosternum Miranda-Ribeiro ( Anura : Leptodactylidae ); 2 larvae ( IBSP 15449), same data; 2 larvae ( IBSP 15450), same date; 2 larvae ( IBSP 15440), same locality and date, ex Rhinella granulosa (Spix) ( Anura : Bufonidae ); 1 larva ( IBSP 15451), Farias Brito Municipality, Ceará state (39° 34 ʹ 24” W, 6° 55 ʹ 34” S), same date, ex Leptodactylus syphax Bokermann ( Anura : Leptodactylidae ).

Type depository. The holotype and paratypes are deposited at the IBSP collection .

Etymology. The specific name ‘ aiuabensis ’ is in honour of the type locality (Auiaba municipality) that the chigger has been found, and in the Tupi language, it means ‘drinking fountain’.

Figures

Figure 1. Hannemania aiuabensis Bassini-Silva, Jacinavicius and Welbourn, n. sp. (holotype); (a) dorsal view of gnathosoma; (b) ventral view of palp. Symbols: ω = solenidion on palptarsus; Odo = odontus; cs = adoral setae; bs = subcapitular setae. Scale bar: 50 μm.

Figure 2. Hannemania aiuabensis Bassini-Silva,Jacinavicius and Welbourn, n. sp. (holotype); prodorsal sclerite. Symbols: ve = external vertical setae; se = external scapular setae; vi = internal vertical setae; si = internal scapular setae (trichobothria). Scale bar: 20 μm.

Figure 3. Hannemania aiuabensis Bassini-Silva, Jacinavicius and Welbourn, n. sp. (paratype); (a) dorsal view of idiosoma; (b) ventral view of idiosoma. Solid circles = ventral setae; open circles = dorsal setae; symbols: c1-c6 = C row setae; d1-d4 = D row setae; e1-e5 = E row setae; f1-f3 = F row setae; 1a = anterior sternal setae; 3a = posterior sternal setae; 1b = coxal field I seta; 2b = coxal field II seta; 3b = coxal field III seta. Scale bars: 100 μm.

Figure 4. Hannemania aiuabensis Bassini-Silva, Jacinavicius and Welbourn, n. sp. (holotype); (a) Leg I; (b) Leg II; (c) Leg III. Solid circles = ventral leg setae; open circles = dorsal leg setae; symbols: ζ’ = dorsal eupathidium on Ta I; ζ” and ζ = subterminal eupathidium on Ta I and II; ω = solenidion on Ta I and II; σ = solenidia on Ge I–III; κ = microsetae on Ge and Ti I; φ, φ’, φ” = solenidia on Ti I–III; ε = famulus on Ta I and II; z = companion seta on Ta I; 1a = anterior sternal setae; 1b = coxal field I seta; 2b = coxal field II seta; 3b = coxal field III seta. Scale bars: a–c 50 μm.