Arvechambus hummi Causey, 1963

Shelley, Rowland M., 2007, Rediagnoses of the milliped genera Pseudojulus Bollman, 1887, and Arvechambus Causey, 1963, in the southeastern USA; description of P. mississippiensis, n. sp. and proposal of the subtribe Pseudojulina (Julida: Parajulidae: Parajulinae: Aniulini), Zootaxa 1541, pp. 1-16 : 12-13

Arvechambus hummi Causey, 1963

Figs. 14–17

Arvechambus hummi Causey, 1963:69 –70, figs. 1–3, 9. Hoffman, 1999:149. Shelley, 2001:243; 2004:202–203, figs. 29– 43.

Arvechambus australis Causey, 1963:71 , figs. 4–6. Hoffman, 1999:149. Shelley, 2001:243.

Type specimens. Of A. hummi : ɗ holotype ( NMNH) and 2ɗ & 1Ψ paratypes ( FSCA, NMNH) collected by H. J. Humm on an unknown date in October or November 1952 in Tallahassee, Leon Co., Florida; 1ɗ & 4Ψ paratypes ( FSCA) collected in Tallahassee by "Ecology Class", November-December 1952; and 1ɗ paratype ( NMNH) collected by R. McFarland, 26 October 1958, 4 mi (6.4 km) S Tallahassee. Of A. australis : ɗ holotype ( NMNH) collected by H. V. Weems, Jr., 20 December 1959, in Gainesville, Alachua Co. , Florida; paratypes, all from Gainesville and collected by W. J. Platt, as follows: 1ɗ ( FSCA) and 1Ψ ( NMNH), 28 October & 22 November 1959, respectively, "on floor in house," 1Ψ ( FSCA), 17 October 1959, "on top of ground in creek ravine area" ( Causey 1963, Hoffman 1999, Shelley 2004).

Diagnosis. Posterior gonopod accessory prefemoral process extending directly ventrad, not overlapping telopodite, expanding at 1/3 length and distally broad, apically sublinear with tooth at caudal corner.

Distribution. Published records exist from Alachua, Baker, Hamilton, Leon , & Liberty cos., Florida, and Thomas Co., Georgia ( Causey 1963; Hoffman 1999; Shelley 2001, 2004); the following new records are available. FLORIDA: Alachua Co. , 5 mi (8 km) S Hawthorne, W side of Lochloosa Lake, ɗ/Ψ (gynandromorph), 11 November 1976, L. R. Davis (FSCA); Gainesville, 1911 SW 34th St, inside Division of Plant Industry Bldg., ɗ, 17 December 1987, A. B. Hamon (FSCA); and 4 mi (6.4 km) E Gainesville, "bait traps," ɗ, 1–19 November 1965, R. E. Woodruff (FSCA). Suwannee Co., 4.3 mi (6.9 km) S Dowling Park, in "pig dung trap" along Suwannee River, ɗ, 20 October 1976, J. R. Wiley (FSCA). Wakulla Co. , 1 mi (1.6 km) S Medart, along US hwy. 98 in Panacea Unit, St. Marks Nat. Wildlife Ref., 2ɗ, 16 March 1978, collector unknown (FSCA).

Remarks. The FSCA contains a specimen from Lochloosa Lake, Alachua Co. (Figs. 14–17), that is a gynandromorph possessing both gonopods and cyphopods; I assign it to A. hummi even though it lacks lobes on the 8th sternum. The reproductive structures are at their proper positions but are aberrant as are the tures and exoskeletons at these locations (see Shelley 2004, figs. 29–30, 42)). Identification is therefore lematical, but only two parajulids occur in this area — Gyniulus bufonius (Chamberlin, 1938) and A. — and the milliped seems too large to be the former; additionally, the bilobed gynaspis is amenable to condition in A. hummi (see Shelley 2004, figs. 43–45).

FIGURE 14. Gynandromorph of Arvechambus hummi from Alachua Co. , Florida, head and rings 1–10, lateral view of right side. The Ψ cyphopods are inside the aperture with the raised margins behind the 1st legs, and the ♂ gonopods are located caudad on ring 7; the right posterior gonopod protrudes through the aperture and is visible externally. Photo by A. E. Bogan.

The ags ( Fig. 15 ) are non-descript and immature-looking, with an elongate, non-clavate telopodite and a broad coxa that continues into a large medial lobe; the conditions of these structures plus the absence of the lateral syncoxal process are compatible with A. hummi and not G. bufonius . The shape of the pgs ( Fig. 16 ), with a broad, basally concave telopodite and a small additional branch arising at the position of a true prefemoral process, does not resemble anything that I have seen; however, the truncated telopodite is consistent with A. hummi . Likewise, the cyphopods ( Fig. 17 ) do not resemble those of either species and possess a receptacle-like structure that nearly envelopes the valves; however, the bilobed gynaspis is consistent with A. hummi and not G. bufonius . There are no eggs inside the body, and as malformed as the structures are, they must all be non-functional. To the best of my knowledge, this is the first report of a gynandromorphic parajulid; Verhoeff (1910) described an individual of Tachypodoiulus niger (Leach, 1815) ( Julida : Julidae ) from Germany, with cyphopods, ovaries, penes, vasa deferentia, and gonopod primordia replacing both pairs of legs on segment 7. Most gynandromorphic conditions in the Diplopoda that I am aware of have been reported for representatives of the Polydesmida, and readers are referred to the works of Brölemann (1898, 1920), Carl (1911, 1914), and Chalande (1903).

Figures

FIGURES 15 – 17. Arvechambus hummi gynandromorph. 15, left anterior gonopod, anterior view. 16, left posterior gonopod, medial view. 17, right cyphopod, caudal view. Scale line = 0.50 mm for all figs.