Research Article |
Corresponding author: Joe A. MacGown ( jmacgown@entomology.msstate.edu ) Academic editor: Andrey Frolov
© 2023 Joe A. MacGown, JoVonn G. Hill.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
MacGown JA, Hill JG (2023) A new species of Hypothyce (Coleoptera, Scarabaeidae, Melolonthinae) from Alabama, United States of America. ZooKeys 1168: 1-10. https://doi.org/10.3897/zookeys.1168.104272
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A new species, Hypothyce rayi MacGown & Hill, sp. nov. (Coleoptera: Scarabaeidae: Melolonthinae: Melolonthini), is described from east central Alabama, USA. Three other species of Hypothyce, H. burnei Skelley, H. mixta Howden and H. osburni (Cartwright) are known to occur in the United States. We discuss differences between these species and provide an updated identification key to the genus.
Coastal Plain, endemic, identification key, sandhills, scarab, taxonomy
Three species of Hypothyce have been reported from North America including H. mixta Howden, only known from Texas; H. burnei Skelley, only reported from Georgia; and H. osburni (Cartwright), only known from Georgia. Here, we describe H. rayi MacGown & Hill, sp. nov., known from one site in east central Alabama, and we provide an updated identification key to the genus.
All of the described species of Hypothyce have been reported to inhabit isolated sandhills along the North American Coastal Plain (
The only known specimens of H. osburni were collected with a blacklight trap at a single locality in a pecan orchard in Doughtery County, Georgia (
Three male specimens of H. rayi were examined and compared to male specimens of H. burnei (three specimens) and H. osburni (one specimen) borrowed from the
Florida Collection of Arthropods, Gainesville, Florida (
This key is based on couplet 6 from
1 | Protibia distinctly tridentate; metatibial spurs longer than two basal tarsomeres; only known from Texas | Hypothyce mixta Howden |
– | Protibia bidentate to slightly tridentate; metatibial spurs shorter than two basal tarsomeres; only known from Alabama and Georgia | 2 |
2 | Apical margin of clypeus truncate to slightly concave (Fig. |
Hypothyce osburni (Cartwright) |
– | Apical margin of clypeus strongly convex (Fig. |
3 |
3 | Length greater than 22 mm; pronotum and elytra with dense, fine pubescence that does not completely obscure the integument except at lateral edges and along midline (Fig. |
Hypothyce burnei Skelley |
– | Length less than 19 mm; pronotum and elytra with dense, thickened, lanceolate yellowish whitish setae that mostly obscures the integument giving it a yellowish-white cast (Fig. |
Hypothyce rayi MacGown & Hill, sp. nov. |
Members of the genus Hypothyce can be distinguished from most Melolonthini (as defined by
Hypothyce rayi (Figs
Holotype male. Total length 17.3 mm, width 8.5 mm (measured at widest part of elytra). Elongate oval; entire body dark reddish brown, integument mostly obscured by dense, appressed, short, yellowish-white, lanceolate setae; pronotum with a distinct median stripe of yellowish-white, lanceolate setae. Head width including eyes 3.3 mm, in dorsal view head including clypeus somewhat rectangular; clypeal width 2.6 mm, clypeal margin broadly rounded and slightly convex at middle, broadly and deeply recurved, trough-like, surface with dense, appressed, short (≈ 0.25 in length), whitish, lanceolate setae that arise from strong punctures, setae projecting inward or anteriorly, setae longer than those on pronotal and elytral dorsum (≈ 0.25 mm as compared to 0.10–0.20 mm); numerous erect, longer, narrower, setae that project posteriorly interspersed between appressed lanceolate setae. Eyes large, 1.5 mm at longest point, visible dorsally and ventrally, distance between eyes (in dorsal view) approximately four times eye length; eye partially bisected anteriorly by a clypeal projection. Antenna reddish brown; with 10 antennomeres including a three-antennomere, lamellate club, length of club subequal to length of antennomeres I–VII; scape (antennomere I) pyriform with stiff, elongate setae projecting apically and along ventral edge; pedicel (antennomere II) similar in shape to scape but lacking setae; antennomeres III–V slightly longer than wide, antennomeres III and V subequal, antennomere IV slightly longer, each with few stiff, elongate setae present medially; antennomeres VIII and IX cupped, wider at base and narrowing apically.
Pronotum wider than long (6.0 mm wide, 4.1 mm long), widest in middle, posterior angles rounded; with dense, appressed, yellowish-white, lanceolate setae, setae shorter (≈ 0.10 mm in length) than on head, denser medially forming a median stripe, less dense at sides of pronotum; rim of pronotum with narrow, upward curved setae present. Scutellum heart shaped, 1.5 mm in length and 1.5 mm at widest point; edges rounded; most of the surface with dense, overlapping, appressed, lanceolate, yellowish-white setae present except along the outer rim where setae are absent, setae longer, wider, and denser than those on elytra.
Elytra 11.0 mm in length, 8.5 mm wide; with strong lateral margins; area posterior of humeri toward outer edges of elytra slightly depressed; elytral surface with dense, appressed, short, yellowish-white, lanceolate setae that mostly obscure integument, setae similar in shape and length to those on pronotum (≈ 0.10 mm in length), setae denser along midline of elytra.
Sterna with dense, overlapping, elongate yellowish-white setae. Abdominal sternites and pygidium with short, appressed, whitish yellow, lanceolate setae that mostly obscure the integument but with margins visible and with a smooth shiny area medially.
Legs
: Femora reddish brown, with dense, yellowish-white, elongate, curved setae and with numerous appressed, yellowish-white, scale-like setae on anterior and ventral surfaces. Protibia reddish brown, with two strong teeth and one smaller tooth located about one third from tibial base, apical tooth strongly curved; one tibial spur present; spine-like setae present along dorsal edge; numerous elongate, erect, curved, setae present ventrally and scattered on anterior surface; numerous appressed, yellowish-white, scale-like setae on anterior and ventral surfaces. Mesotibia reddish brown, lacking large, curved teeth, but with two partial ridges located about 1/3 and 2/3 from tibial base, extending from ventral edge and angling across anterior surface toward apex of tibia, each with a row of spine-like setae present; two tibial spurs present, one about 1.5 times as long as the other; tibia widened apically and rimmed with elongate spine-like setae; spine-like setae present along dorsal edge; numerous elongate, erect, curved, setae present ventrally and scattered on anterior surface; numerous appressed, and yellowish-white, scale-like setae on anterior surface. Metabia (Fig.
Genitalia
: In lateral view parameres widened apically into a flattened club shape, upper part of club rounded rectangular and lower area in the form of a rounded triangle (Fig.
Length 17.3–18.7 mm, width 8.5–8.8 mm (N = 3). Notable variation was not observed in setation or other physical characteristics.
Holotype , male, “Hale Co., AL, 32.9964°, -87.4932°, July 16, 2018, coll: Alan Jeon, found resting on leaf in pine scrub habitat [MEM].” Two paratypes have the same data as the holotype except collections were made on July 8, 2018, and July 21, 2018 [MEM].
We named this species in honor of Dr. Charles Ray, an Alabama naturalist who recognized that this collection represented a new species.
As with the other two species of eastern Hypothyce, H. burnei and H. osburni, little is known about the natural history of H. rayi. All three species appear to be restricted to sandhill habitats, each geographically separated from one another. Thus far, only males of the three eastern species have been collected, and they were capable of flight. Although the females for these three species are still unknown,
The type specimens of H. rayi were collected by Jeon in mid to late July on vegetation at night in what he described as scrub habitat in a longleaf forest. Charles Ray and MacGown made a return trip to the type locality in late August 2022, with several subsequent trips by Ray throughout the month, in hopes of finding additional specimens of H. rayi, especially females, which are unknown, but were unsuccessful in finding specimens. We believed that the habitat had changed significantly from 2018 when the beetles were collected, as the area now had a thick understory present (Fig.
We thank Charles Ray for recognizing that specimens of Hypothyce from Hale County, Alabama appeared to be a new species; Alan Jeon for the collection of specimens of H. rayi; and to the Florida Collection of Arthropods, Gainesville, Florida (
No conflict of interest was declared.
No ethical statement was reported.
This work was partially supported by funding from the National Institute of Food and Agriculture under project 211140.
MacGown wrote the manucript and prepared figures. HIll coordinated and suggested the project, and provided editing.
All of the data that support the findings of this study are available in the main text.