Bellisotoma ewingi (James), 1933

Soto-Adames, Felipe N., Giordano, Rosanna & Christiansen, Kenneth, 2013, Bellisotoma, a new genus of Isotomidae from North America (Hexapoda, Collembola), ZooKeys 283, pp. 7-13 : 10

Bellisotoma ewingi (James), 1933 comb. n.

Material examined.

Mississippi, Vicksburg; in decaying leaves and twigs, October 2, H.E. Ewing, coll.; Lectotype, designated by J.T. Salmon, 1958; original US National Museum of Natural History catalog number 42981; current catalog number 9026.

Remarks.

The description provided by Folsom (1937) suggests that Ballistura ewingi and Bellisotoma joycei are very similar, sharing characters such as cuticle ornamentation, presence of 3 guard sensilla on the third antennal segment, distal tibiotarsal subsegmentation, and general eye, claw and furcula structure. Of the three main characters used to diagnose Bellisotoma , Ballistura ewingi has the large number of dental setae and the general lamellate structure of the mucro. The only diagnostic character remaining to be scored for Ballistura ewingi is the sensillar polychaetosis.

We studied the lectotype of Ballistura ewingi , but the specimen is in such poor condition (Fig. 10) that most characters could not be scored. The few characters we were able to observe are: tergal sensilla present, although clearly seen only on Abd. 4; tibiotarsal setae B4 and B5 present; tenent hair apparently 1,2,2, and acuminate; tenaculum with 3 teeth; dens ventrally with 4 setae; mucro with two lamellae as in Fig. 9.

The tenent hairs and tenacular teeth in the lectotype of Ballistura ewingi are as in Ballistura joycei , and differ from the numbers reported by Folsom (1937) (2,2,2 or 3,3,3 hairs; 2 teeth). This leaves only the number of distal setae on the collophore to distinguish Ballistura joycei (11 setae) from Ballistura ewingi (4 setae), and it is possible that James species is a senior synonym of Ballistura joycei . However, the condition of the lectotype is such that we prefer to await the study of fresh material from Mississippi before proposing a definite change in nomenclature. In any case, the similarities between ewingi and joycei listed above, justify the transfer of ewingi to the genus Bellisotoma .