Polyphylla starkae Skelley, 2009

Skelley, Paul E., 2009, A new species of Polyphylla Harris from peninsular Florida Coleoptera: Scarabaeidae: Melolonthinae) with a key to species of the pubescens species group, Insecta Mundi 2009 (85), pp. 1-14 : 2-6

Polyphylla starkae Skelley , new species

Figure 2-7 , 10, 14, 18, 22-23, 30-32

Diagnosis. Polyphylla starkae is a member of the pubescens species group and unique with males having elytral setae clustered into groups, some in vague stripes ( Fig. 2, 4 , 22 ). This species is the largest member of the pubescens group and is strongly sexually dimorphic. Females are more robust than the males ( Fig. 3, 5 , 23 ) with legs modified for burrowing (compare Fig. 10, 14) and elytral setae nearly absent. Although flight wings appear fully developed, female elytra are tightly connected at the base along the suture, suggesting females are flightless.

Description. Male Holotype. Length 23 mm; width 11 mm. Body reddish-brown to nearly black with overlying vestiture of golden setae generally dense all over. Head between eyes with moderately coarse punctures separated by about 1 x their diameter, punctures of frons with long erect setae. Clypeus transverse, 2 x wider than long, with broadly reflexed margin, anterior angles rounded; anterior margin broadly truncate in dorsal view, weakly sinuate in anterior view; surface punctures slightly larger than those on frons, separated by 0.5-1.0 x their diameter, setae moderately appressed, not erect. Antennae uniformly pale brown; antennal club large, length 1.5 x width of clypeus.

Pronotal width = 1.8 x length; lateral margin rounded, weakly serrate because of setae bearing punctures; surface glossy between punctures; punctures coarse, same size as on clypeus, separated by less than 0.5 x their diameter near anterior and posterior angles, less dense on disc where variably separated by 1.0-4.0 x their diameter; each puncture bearing an appressed seta, lateral setae distinctly shorter than those on disc. Pronotal hypomeron with scattered coarse punctures bearing long erect setae, except for completely glabrous apicolateral third near pronotal angle. Scutellum with coarse punctures and setae as on disc, setose punctures nearly coalescing along midline, much sparser laterally.

Elytral length 3.2 x length of pronotum; lateral margin moderately reflexed, reflexed lateral edge reaching middle of humerus, not attaining base; surface glossy with glabrous areas near base and coarsely punctate areas on apical two thirds between patches of dense fine punctures, all punctures bearing short appressed seta, setal patches vaguely linear in arrangement, setal covering along the sutural, apical and lateral margins complete although variable in width. Flight wings present, fully functional (specimen observed flying). Venter with metathorax densely covered with long erect golden setae. Each abdominal sternite with band of setae bearing punctures on apical half, band wide laterally, narrowed medially, setae appressed; punctures on first three visible sternites fine and dense, punctures on last two visible sternites 3 x diameter of those on basal sternites, all punctures separated by 1-2 x their diameters.

All femora somewhat flattened. Pro- and mesofemora narrowed, parallel-sided most of length. Metafemora weakly dilated, wider than mesofemora, margins arcuate, length 3.1 x maximal width. Protibia elongate, with apical tooth and second tooth at apical quarter. Mesotibia narrow entire length, not expanded at apex; with weak external tooth at middle of outer edge small; tooth at basal fourth lacking. Metatibia slender, parallel-sided most of length, wider at apex; width at apex = midline length of third visible abdominal sternite; inner tibial margin slightly curved at apex. Metatibial spurs narrowed to acute point. Legs reddish-brown, contrasting with dark pronotum. All tarsi with tooth on posterior claw 0.75 x length of tooth on anterior claw. Genitalia with paramere length 2.5 x basal width in dorsal view, abruptly narrowed at middle; each paramere with dorsal-lateral groove from middle to apical quarter; apex laterally flattened and rounded in lateral view ( Fig. 30-32 ).

Female Allotype. Length 25 mm; width 13 mm. Body reddish-brown, elytral and abdominal cuticle thin, structures underneath visible when alive, dorsal vestiture of thin setae sparse. Head between eyes with coarse punctures separated by about 1 x their diameter, punctures of frons with long erect setae. Clypeus trapezoidal, sides converging anteriorly, 2 x wider than long, with narrowly reflexed margin, anterior angles rounded; anterior margin broadly truncate in dorsal view, straight in anterior view; surface punctures same size and distribution as on frons, setae moderately appressed, not erect. Antenna unicolorous pale brown; antennal club short, length 0.25 x width of clypeus.

Pronotal width = 1.7 x length; lateral margin rounded; surface glossy between widely scattered coarse punctures, punctures size 1.0-1.5 x those on clypeus, separated by less than 0.5 x their diameter near anterior and posterior angles, less dense on disc where variably separated by 1.0-4.0 x their diameter; each puncture bearing a seta, which vary from somewhat appressed to erect, lateral setae shorter than those on disc. Pronotal hypomeron with scattered coarse punctures bearing long erect setae, except for completely glabrous apical-lateral third near pronotal angle. Scutellum with laterally with coarse punctures and setae as on disc, smaller punctures nearly coalescing along midline.

Elytral length 3.3 x length of pronotum; lateral margin weakly reflexed, sharp lateral edge reaching middle of humerus, not attaining base; surface glossy and mostly glabrous with widely scattered punctures bearing fine setae; setal covering visible along the sutural, apical and lateral margins complete although variable in width; elytra were tightly connected at basal quarter along suture and they were separated with some difficulty. Flight wings present. Venter with metathorax and abdomen similar to male holotype.

All femora with surface somewhat convex. Pro- and mesofemora weakly arcuate most of length. Metafemora distinctly dilated, 1.5 x wider than mesofemora, margins strongly arcuate, length 2.1 x maximal width. Protibia broad, distinctly tridentate, with elongate apical tooth, elongate middle tooth at apical third, triangular basal tooth at basal quarter. Mesotibia slender entire length, not expanded at apex, width 0.5 x mesofemoral width; with small external tooth at middle of outer edge; tooth at basal fourth lacking; apical spurs narrowed to acute apex spatulate, slightly curved downward, upper spur shorter than lower spur. Metatibia parallel-sided along middle half of length; tooth at middle of outer edge weak; abruptly widened near apex; apical spurs curve downward on lower edge; lower spur flattened, gradually narrowing to acute apex, upper spur somewhat spatulate, widest at middle; portion of apical tibial plate below tarsal junction same size as upper part. All tarsi with teeth equal in size.

Variation. Male. Length 21-25 mm; width 10-12 mm. Anterior clypeal margin on most is weakly sinuate in anterior view, is somewhat raised in the middle on a few. Lateral pronotal margin, evenly arcuate on most, is slightly angulate on a few. Patches of elytral setae vary in size in the specimens available. On some, their somewhat linear arrangement is clearer, but never prominent, on others it is imperceptible. The elytral pattern of radiating lines in reflected light is not visible in most specimens. Two specimens studied had patterning identical to the other members of this group. Body color also varied from light brown to dark brown, almost black.

Female. Length 23-25 mm; width 13-14 mm. Body color in life varied from the reddish-brown ( Fig. 3, 5 ) to a chocolate brown, similar to the pinned specimen in Figure 23 . All specimens darkened when preserved.

Type Locality. Auburndale, Florida, USA ( Fig. 1 ), which is geographically part of the Winter Haven Ridge. For conservation purposes, and until more populations are discovered, the exact coordinates are not provided here.

Type Materials. Male holotype and female allotype label data as follows: FLORIDA: Polk Co., Auburndale, 15 April 2009, P. Skelley, R. Morris, T. Palmer, mating at dusk.

Paratypes (40) were all collected at the same locality by various collectors, here listed in alphabetical order: D. Almquist, R. Morris, T. Palmer, P. Skelley, D. Stark. Unless otherwise noted, paratypes were collected at light on the following dates: 10-IV-2007 (3M); 22-IV-2008 (8M); 8-V-2008 (1M); 4-IV-2009 (2M); 6-IV-2009 (1M); 6-IV-2009, flying at 4:56 pm (1M); 9-IV-2009 (10M); 11-IV-2009 (4M); 12-IV-2009 (1M); 14- IV-2009, under ground after dusk (1F); 15-IV-2009, mating at dusk (2F, 4M); 26-IV-2009 (2M).

The holotype, allotype and a series of paratypes are deposited in the Florida State Collection of Arthropods , Gainesville, FL ( FSCA). At least one paratype will be deposited in each of the following collections: Archbold Biological Station, Lake Placid, FL ( ABSC) ; A. V. Evans, Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, VA ( AVRC) ; Natural History Museum , London ( BMNH) ; Canadian Museum of Nature , Ottawa, Canada ( CMNC) ; D. A. LaRue, Entomology Research Museum , University of California, Riverside, CA ( DALC) ; D. Stark, Lakeland , FL ( DSIC) ; D. E. Russell, Miami University , Oxford, OH ( DERC) ; J. Zidek , Praha, Czech Republic ( JZIC) ; M. J. Paulsen, Lincoln , NE ( MJPC) ; National Museum of Natural History , Smithsonian Institution, Washington, DC ( NMNH) ; R. F. Morris, Lakeland , FL ( RFMC) ; University of Nebraska State Museum , Lincoln, NE ( UNSM) ; and W. B. Warner, Chandler , AZ ( WBWC) .

Etymology. Named for Donna Stark, who first collected this beetle, attempted to identify it, and brought it to our attention (see Palmer 2009). Survey efforts such as hers are greatly needed to discover and document our indigenous invertebrate fauna.

Common Names. Woodruff and Deyrup (1994) called “ P. pubescens ” the “panhandle beach scarab.” Unfortunately, this name refers to the species later recognized and named P. woodruffi Skelley (2004) . True P. pubescens is not known to occur on beaches and is here named the “Eglin uplands scarab”. Given the immediate interest P. starkae has raised among naturalists, conservation groups and other political entities in Florida, it is fitting to propose a common name for this new species. Thus, I am proposing P. starkae be known as the “Auburndale scrub scarab.”

Figures

Figure 1-5. Polyphylla starkae, new species. 1) Clear cut type locality in April 2009. 2-5) Adult beetles, male on left, female on right, courtesy D. Almquist, FNAI.

Figure 6-9. Polyphylla spp. head and pronotum, males on left, females on right. 6-7) Polyphylla starkae. 8-9) Polyphylla pubescens.

Figure 22-29. Polyphylla - pubescens species group, male (left) and female (right). 22-23) P. starkae. 24-25) P. donaldsoni. 26-27) P. pubescens. 28-29) P. woodruffi. These images were taken and reproduced at the same magnification.

Figure 30-32. Polyphylla starkae, male genitalia. 30) Caudal view. 31) Lateral view. 32) Dorsal view. Scale line = 1.0 mm.