Polyphylla stellata Young

La Rue, Delbert A., 2016, Natural history, ecology, and conservation of the genus Polyphylla Harris, 1841. 1. New species from the southwestern United States and Baja California, Mexico, with notes on distribution and synonymy (Coleoptera: Scarabaeidae: Melolonthinae), Insecta Mundi 2016 (491), pp. 1-41 : 26

Polyphylla stellata Young

( Fig. 45–47 )

Female description. Based on two specimens labeled “ USA, California: Contra Costa Co., East Antioch, 14.V.1994, S.E. Haskins” same data except 10.VI.1994 (DALC).

Length 21.0– 24.5 mm. Greatest width 10.5–12.0 mm. Humeral width 9.5–10.0 mm. Excluding sexual dimorphic variation as male except: Form. Robust, slightly ovate, widest at posterior 1/2. Color. Head and pronotum rufotestaceous; elytra appearing black to piceous, rufotestaceous to deep rufotestaceous under magnification (10.5×); venter and exposed abdominal sternites pale testaceous to rufotestaceous. Head. Anterior clypeal margin feebly to strongly bisinuate; lateral clypeal margins subparallel. Pronotum. Pale setae uniformly distributed over entire disc; lateral marginal bead crenulate. Elytra. Vittate, vittae fragmented, sublinear, composed of fragmented patches of small, white squamae; short, recumbent pale setae randomly scattered over disc or confined to elytral declivities. Pygidium. Pale setae uniformly distributed over disc. Venter. Squamal and setal vestiture reduced. Legs. Protibia strongly tridentate, dentition widely separated; pale straw-colored setae uniformly distributed over anterior surface, or nearly glabrous; distal tooth strongly recurved; anterior mesotibial surface with coarse dentiform projections.

Remarks. The distribution and ecological associations of this species were previously amended ( La Rue 1998).

The females were encountered within or partially emerged from their burrows in hard-packed clay soil while observing male flight behavior at dusk. Males were attracted to a blacklight placed in an area of sandy alluvial soil (S.E. Haskins, personal communication).

Remnants of the Antioch Sand Dunes continue to support what remains of an oak-willow woodland canopy with a ground cover of scattered forbs and grasses. Ecologically, these habitat parameters correspond to extant populations of P. stellata in Sacramento County, CA ( La Rue 1998).

Figures

Figures 42–47. Described females and comparative male. Polyphylla monahansensis Hardy and Andrews. 42) Male. 43–44) Female. Polyphylla stellata Young. 45) Male. 46–47) Female.