Gaeolaelaps nolli (Karg)

Joharchi, Omid & Negm, Mohamed W., 2020, Soil-inhabiting mites of the family Laelapidae (Acari: Mesostigmata) from Assiut Governorate, Egypt, Zootaxa 4759 (4), pp. 488-510 : 498-499

Gaeolaelaps nolli (Karg)

Figures 28–30 .

Hypoaspis nolli Karg, 1962: 62 .

Hypoaspis nolli .— Karg, 1965: 311; Costa, 1968: 9.

Hypoaspis (Hypoaspis) nolli .— Karg, 1971: 169, 1978: 16.

Hypoaspis (Geolaelaps) nolli .— Karg, 1979: 80, 1982: 239, 1993: 140, 2006: 148; Xu & Liang, 1996: 191.

Hypoaspis (Gaeolaelaps) nolli .— Faraji et al., 2008: 207.

Gaeolaelaps nolli .— Farrier & Hennessey, 1993: 73; Beaulieu, 2009: 36; Bahrami et al., 2011: 351; Trach, 2012: 162; Kavianpour et al., 2013: 7; Nemati & Mohseni, 2013: 80; Kavianpour & Nemati, 2014: 321; Joharchi et al., 2018: 24.

Hypoaspis praesternalis .— Evans, 1953: 272 (misidentification). Hypoaspis (Gaeolaelaps) praesternalis .— Evans & Till, 1966: 173 (synonymy by Kavianpour et al., 2013: 7); Kavianpour & Nemati, 2014: 321.

Gaeolaelaps praesternalis .— Joharchi et al., 2018: 24 (misidentification); Joharchi et al., 2019b: 81 (misidentification).

Specimens examined. Holotype Hypoaspis nolli Karg, 1962 : ZMB Kat. Nr. 40849, Versuchsfeld Kleinmachnow d. Berlin, 17.08.1957. One female; 27°11’ N, 31°09’ E, Assiut University , Assiut; 15 May 2016; coll. M.W. Negm; ex. soil.

Remarks. Gaeolaelaps nolli was described from agricultural soil and grassland in Germany ( Karg, 1962). It is now recorded in Egypt for the first time, from soil. The synonymy presented above reveals some confusion about the identity of this species. Much of the information on this species has been published under the names Gaeolaelaps praesternalis or Hypoaspis (Gaeolaelaps) praesternalis . The original description of Hypoaspis praesternalis by Willmann (1949) is brief, and both the description and illustrations lack some important details. The description of Hypoaspis nolli Karg, 1962 is more detailed, but does not include a direct comparison with H. praesternalis .

Evans & Till (1966) synonymised these two species, but did not provide any explanation for that decision, and did not give details of the specimens they examined. This has probably led to the ambiguity about the identification of these two different species. Karg (1993) included both species in his key to species of Hypoaspis (Geolaelaps) . The first author had the chance to examine both species in Karg’s collection which deposited in the Museum für Naturkunde Berlin in Germany. Thus, we can easily distinguish between these two species as follows:

1- size of body in G. nolli is larger than G. praesternalis ( Figs 28 & 31 ).

2- dorsal shield setae short, none of them reach to base of next setae in G. praesternalis while much longer in G. nolli (some setae in the opisthonotal region long enough to reach the base of the next posterior setae) ( Figs 28 & 31 ).

3- ornamentation of genital shield, posterior eight irregular cells flanked by a median inverse Y-shaped ornamentation in G. nolli while in G. praesternalis with the same inverse Y-shaped ornamentation medially but almost completely smooth (or faintly reticulated) posteriorly ( Figs 29 & 32 ).

4- the length of the peritreme short, reaches to mid-level of coxa II in G. nolli while much longer in G. praesternalis (reaches at least to anterior level of coxa I) ( Figs 30 & 33 ).

5- tarsus IV with two very long setae pd2, pd 3 in G. nolli while tarsus IV without any long setae in G. praesternalis (ad2 and ad3 longer than other setae on segment).

We have been unable to locate the holotype of H. praesternalis . It is not present in the Willmann collection in the Zoologische Staatssammlungen, München (Stefan Friedrich, pers. comm.). The information on morphological characters of G. praesternalis is based on the two females (ZMB Kat. Nr. 41038 & ZMB Kat. Nr. 41054) from Germany in museum für naturkunde, Berlin, Germany, identified by Prof. Dr. habil. Wolfang Karg as Hypoaspis praesternalis Willmann, 1949 .

Figures

FIGURES 28–33. FIGURES 28–30. DIC micrographs of Gaeolaelaps nolli (Karg, 1962) (holotype, ZMB Kat. Nr. 40849), female. 28, idiosoma in dorsal view; 29, genital shield; 30, stigma, peritreme & peritrematal shield. FIGURES 31–33. DIC micrographs of Gaeolaelaps praesternalis (Willmann, 1949) (ZMB Kat. Nr. 41038 & ZMB Kat. Nr. 41054), female. 31, idiosoma in dorsal view; 32, genital shield; 33, stigma, peritreme & peritrematal shield.