(104 OTfol) Orthonychiurus folsomi (Schäffer, 1900)

*gotoi (Chowdhury, 1958)
*musae (Selga, 1962)
*sinensis (Stach, 1954)

Orthonychiurus (formerly Onychiurus) folsomi has only been recorded from heated glasshouses. Anal spines are absent and the post-antennal organ is elliptical with about 10 to 12 complex vesicles (Fig. 1). Pseudocelli (PSO) are absent from the first thoracic segment (the typical PSO formula is 32/022/33342). The tibiotarsi of the legs bear nine distal setae and the empodium is long and filamentous reaching the same length as the claw (Figs. 2, 3). Males possess a row of four thick spine-like ventral setae on the second abdominal segment (Figs. 4 and 5). The largest specimen Steve saw which fits the above description was 1.9 mm in length.
Orthonychiurus folsomi is clearly introduced and must be present in numerous other similar localities. The map includes records for the junior synonyms Orthonychiurus gotoi, and Orthonychiurus sinensis.

 

 

 

Orthonychiurus folsomi distribution map

Fig. 1 (above): Post-antennal organ (PAO) of Orthonychiurus folsomi collected from a glasshouse at Silwood Park, Ascot in November 1977 by Brian Pitkin.

Fig. 2 (above) and Fig. 3 (below): Foot of third leg of the same specimen of Orthonychiurus folsomi shown in Fig. 1 at two levels of focus. The tibiotarsus bears nine apical setae (1 to 9) and the empodium (emp) is long and filamentous and is about the same length as the claw.

Fig. 3 like Fig 2, shows thet foot of third leg of the same specimen of Orthonychiurus folsomi shown in Fig. 1 at two levels of focus. The tibiotarsus bears nine apical setae (1 to 9) and the empodium (emp) is long and filamentous and is about the same length as the claw.

Fig. 4: Ventral side of the second (abd2) and third (abd3) abdominal segments of a male specimen of Orthonychiurus folsomi collected from a UK 'greenhouse' in June 1926 by G. Munro (exact locality not known). The area enclosed by the green box is shown in Fig. 5.

Fig. 5: Higher magnification view of the area enclosed by the green box shown in Fig. 4. The ventral side of the second abdominal segment bears four thick spine-like ventral setae ( 1 to 4).

 
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