Petralycus celtisacinus McDaniel & Bolen, 1983

Petralycus celtisacinus McDaniel & Bolen, 1983 View in CoL

( Figs. 45A–D, 46A–G)

Petralycus celtisacinus McDaniel & Bolen, 1983: 811 View in CoL , figs. 1–2; Uusitalo 2010: 76.

Redescription. Dorsum (n= 2 females, Fig. 45A, B). Length 246 µm; dorsum holotrichous, setae born on microplates, each seta plumose with a slightly swollen but tapering shaft, setae longest on caudal segments; lamellae inserted quite densely at regular intervals on continuous striae; naso ca. 20 µm, narrow and rounded at tip; setae vi sparsely ciliated; sce reduced in size; setae in slightly elongated; setae exp and eyes absent; sensilla sci filiform with short cilia; sensilla ve rounded, all prodorsal setae inserted on hard integument.

Venter ( Figs. 45D, 46G). Ventral side neotrichous with small stellate setae; 14 genital setae per valve, 1 pair of eugenital setae; 4 anal setae per valve.

Gnathosoma ( Fig. 45C). 3 pairs of elongated setae on subcapitulum; chelicerae chelate-dentate,robust, elongated, with 1 pair of smooth cheliceral setae; large palpal solenidion reaching over two nude and apical eupathidia, tactile setae elongated.

Legs ( Figs. 46A–F). Pedal setae ciliate and elongated; ca. 30 foot-shaped eupathidia ventrodistally on tarsus I; solenidial formula for tarsi, tibiae, genua and femora on legs I, II, III and IV, respectively: 1-1-0-0, 2-2-2-2, 5-2-2-2, 5-1-1-2+0; famulus I placed abaxially, near distal end of tarsus I.

Material examined. 2 females as Petralycus from mesquite grass ( Hilaria belangeri ), a riparian woodland known as Hackberry Motte, Monument Road, Walder Foundation, Sinton, San Patricio Co., Texas, USA, 23 November 1977, Eric G. Bolen, slides TAMU-ENTO X1645288 (used for drawings), TAMU-ENTO X1642983 (collected 23 November 1977) and TAMU-ENTO X1642865, nymph (collected 2 February 1977); deposited at the Texas A&M University Insect Collection, Department of Entomology.

Differential diagnosis. The six presently known species of the genus Petralycus , each have their own unique solenidiotaxy ( Table 1). The American species P. celtisacinus and P. obtusicornis have chelicerae with a seta but the chelicerae of P. caryapecaus and the European P. unicornis are bald. All four have a holotrichous setal pattern while the African species P. longicornis and P. brevicornis are neotrichous. The naso is blunt-tipped in the American species and P. longicornis but with a sharp point in P. unicornis and P. brevicornis .

Remarks. According to McDaniel & Bolen (1983): “The holotype specimen of P. celtisacinus will be deposited with National Museum of Natural History, Washington, D.C.”—but the specimen is not in their database (Dr. Debra Creel, in litt.).

The three specimens, labelled only as Petralycus , but collected five months earlier from the same locality as the holotype of P. celtisacinus by Eric G. Bolen, are assumed here to be conspecific with P. celtisacinus because of the similar solenidiotaxy, in spite of scanty numbers of tactile setae. The adult specimen used in the redescription bears no dorsal or anal setae at all, but there is a holotrichous number of tiny microplates (33) indicating the insertion points of lost dorsal setae on the tattered integument, but held together by ventral skin (between two black lines in Fig. 45A). Setae from the two other specimens were used as models in the depiction. The length of the species is from the original description.

* There is only 1 solenidion on tarsus I ( McDaniel & Bolen 1983: fig 3), but 4 are in the text that is apparently a typing error. ** Theron (1977: 42) reports either 3 setae and 2 solenidia or 4 setae and 1 solenidion on genu IV.

*** Figure 17 in Theron (1977: 43) shows no solenidia on leg II, but they are present in the holotype .