Neoschoengastia longipes Nadchatram, 1967

K, Sirikamon Koosakulnirand, RajasegaranK, Praveena, Alkathiry K, Hadil A., ChaisiriK, Kittipong, RoundK, Philip D., Eiamampai, Krairat, Ahmad KhusainiK, Mohd K. S., RamjiK, Mohamad Fizl Sidq, AbubakarK, Sazaly, Ya’cobK, Zubaidah, Stekolnikov K, Alexandr A. & Makepeace K, Benjamin L., 2023, On the taxonomy of chigger mites (Acariformes: Trombiculidae) parasitizing birds in Thailand and Malaysia, with the description of a new species, Acarologia 63 (4), pp. 1109-1138 : 1125-1127

Neoschoengastia longipes Nadchatram, 1967

( Fig. 5C )

Diagnosis — SIF = 7BS-B-3-3111.0000; fPp = B/B/BNB; fCx = 1.1.3; fSt = 2.2; AL ≥ PL> AM; fD = 2H-6-6-4-6-4-2 (6-6-4-4-6, 6-6-6-6-4, and other similar variants); Ip = 1140 – 1294; DS = 28 – 31; V = 19 – 25; NDV = 50 – 54; onychotriches present on claws and empodium. Standard measurements are given in Table 6.

Distribution and hosts — THAILAND, ex 14 bird species ( Stekolnikov 2021a). Alcedo atthis , Calliope calliope , Larvivora cyane , and Otus sunia are new host species.

Material examined — Two larvae ( ZIN 17946, 17947) ex Alcedo atthis and Larvivora cyane , THAILAND, Rayong province, Koh Mun Nai, 12.612384°N, 101.687574°E, 9 March

2021, coll. S. Koosakulnirand; six larvae ( ZIN 17948 – 17953) ex four Copsychus malabaricus (4), Cyornis tickelliae (1), and L. cyane (1), THAILAND, Kanchanaburi province, SW Mahidol University Campus, 14.11806°N, 99.15253°E, 8 – 9 December 2021, coll. S. Koosakulnirand;

one larva ( ZIN 17954) ex C. malabaricus , THAILAND, Kanchanaburi province, W Mahidol University Campus, 14.13111°N, 99.14863°E, 10 December 2021, coll. S. Koosakulnirand.

A great many (42) larvae (UoL) from the same localities, same and additional individuals of the same host species, plus 13 larvae ex four C. malabaricus (7), two C. tickelliae (2),

and three L. cyane(4), THAILAND, Kanchanaburi province, W Mahidol University Campus, 14.134225°N, 99.1374365°E, 11 December 2021, coll. S. Koosakulnirand; nine larvae (UoL) ex two Calliope calliope (4), one L. cyane(3), and one Otus sunia (2), THAILAND, Kanchanaburi province, NW Mahidol University Campus, 14.154772°N, 99.1193296°E, 12 December 2021,

coll. S. Koosakulnirand.

Remarks — Neoschoengastia longipes belongs to the group of species close to N. americana , which is characterized by the presence of three setae on coxa III (fCx = 1.1.3). Nadchatram (1967a) compared N. longipes with Neoschoengastia entomyza Womersley, 1952 and Neoschoengastia thomasi ( Radford, 1946) . The main difference between N. longipes plus N. thomasi and N. americana is the presence of six setae in the first posthumeral row vs. eight. Our material on N. longipes also differs from two specimens of N. americana collected in Paraguay ( Stekolnikov et al. 2022) by NDV = 50 – 54 vs. 61 – 62, AP = 34 – 41 vs. 28 – 31,

and AL = 59 – 74 vs. 47. The difference by AL and, to a lesser extent, by AP agrees with the morphometric data on N. americana provided by Domrow (1974). However, the mean values of measurements from Malaysian specimens identified as N. americana by Domrow & Nadchatram (1960) differed from ours. In addition, the specimens examined by Domrow & Nadchatram (1960) were characterized by the presence of two additional sternal setae (fSt = 2.4. vs. 2.2). Probably, they belong to a new and still undescribed species. Neoschoengastia entomyza , a species described from Australia, was synonymized with N. americana by Domrow (1974), but we believe that these two taxa require a more detailed comparison. Thus, the presence of N. americana outside the American continent remains questionable. Neoschoengastia thomasi was described incompletely, without characters of gnathosoma and legs ( Radford 1946). According to the redescription prepared by Nadchatram (1967a) on the base of the type specimen deposited in the British Museum (Natural History), London (currently, Natural History Museum), N. thomasi differs from N. americana and N. longipes by the branched lateral palpal tibial seta (fPp = B/B/BbB vs. B/B/BNB). The redescription was illustrated with a drawing of the scutum lacking all setae except for one AL and one PL ( Nadchatram 1967a, fig. 17). Surprisingly, the cuticular striations in the medial part of the scutum were drawn as transverse, whereas they are longitudinal in all above species. As noted by Domrow and Lester (1985), this drawing rather corresponds to Neoschoengastia struthidia Womersley, 1952 . Fernandes and Kulkarni (2003) based their redescription of N. thomasi on existing literature. Unfortunately, the size of the N. thomasi type series and the place of deposition of other type specimens is unknown. Therefore, it remains a dubious species. Among our N. longipes material, three measured specimens (ZIN 17951, 17953, 17954)

from Copsychus malabaricus collected 9 – 10 December 2021 differ from five other measured specimens by a lesser NDV (50 vs. 53 – 54) smaller scutum (AW = 46 – 50 vs. 51 – 58; SB = 26

– 28 vs. 29 – 35; SD = 44 – 47 vs. 49 – 56), and shorter legs (Ip = 1197 – 1210 vs 1222 – 1294;

TaIIIL = 122 – 128 vs. 131 – 139). We provisionally consider this as a case of intraspecific variability.

Figures

Figure 5 Toritrombicula kirhocephalesGoff, 1982: A – specimen ZIN 18009, anterior dorsal aspect of idiosoma. Toritrombicula uphami Nadchatram, 1967: B – specimen ZIN 18169, anterior dorsal aspect of idiosoma. Neoschoengastia longipesNadchatram, 1967: C – specimen ZIN 17947, dorsal aspect of idiosoma. Schoengastia archaea(Taufflieb, 1960): D – specimen ZIN 17967, dorsal aspect of idiosoma.