Aegialia shimeki Lago and Freese, 2016

Lago, Paul K. & Freese, Edwin L., 2016, A New Species ofAegialiaLatreille (Coleoptera: Scarabaeidae: Aphodiinae) from Southeastern Iowa, USA, The Coleopterists Bulletin 70 (2), pp. 341-346 : 341-346

Aegialia shimeki Lago and Freese , new species

Description. Holotype, male, length 4.25 mm, maximum width 2.0 mm. Form elongate-oval, convex, widest in apical third ( Fig. 1 ). Dorsum and venter piceous; anterior clypeus, anterior and lateral pronotal margins, sutural intervals, and humeral umbones of elytra lighter reddish brown; elytral disc dark, but lighter than pronotal disc, lateral margins ambiguously lighter than disk; antennae yellowish, legs reddish brown, shiny. Head densely granulate, impunctate. Terminal maxillary palpomere cylindrical, about 3X longer than wide, widest near base and tapering apically. Clypeal margin vaguely emarginate apically, gena slightly produced. Pronotum 0.4X elytral length, moderately shiny, coarsely punctate, punctures separated by up to 1 diameter on disk, anterior corners with punctures sparser and less impressed, vaguely rugose, postero-lateral corners nearly smooth with punctures smaller, even more superficial, nearly absent, lighter anterior margin nearly impunctate, lateral edges of disk mesad of lateral bump with 1 deep, transverse depression about 2X longer than wide; lateral and basal marginal line complete, lateral margin entire, not crenate, basal margin slightly sinuate making posterior median angle weakly salient, basal marginal line more prominent medially than laterally. Elytra with intervals moderately convex, nearly impunctate, striae distinctly impressed, coarsely punctate, punctures separated by slightly more than 1 diameter. Functional wings present and fully developed. Metasternum with median, longitudinal groove, disk smooth and shiny, with few fine to moderate punctures, laterally punctate, finely granulate, alutaceous. Sternites punctate-granulate. Coxae similarly granulate-punctate, except procoxae smooth on lateral quarter. Granulate surfaces setose. Protibia tridentate. Ventral face of profemur densely punctate, setose in posterior half, anteriorly smooth, shiny. Mesofemur smooth, shiny, anterior quarter with widely spaced, erect setae, posteriorly with a row of 8 setose punctures. Mesotibia slender, with sparse surface denticles in basal half, with an incomplete transverse carina at apical 2/3, apical spurs slender, inner spur acute, widest at 2/3 length tapering to narrow apex, about as long as first 4 tarsomeres, outer spur narrowly spatulate, widest at apical 3/4. Metafemur nearly 1.5X wider than mesofemur, mostly smooth and shiny, anterior quarter with sparse, deep, setose punctures, with posterior lateral line of 5 setose punctures, posterior margin sinuate, slightly concave before expanded apical flange. Metatibia slender with numerous surface denticles, short, partial, transverse carina present at apical 2/3, apical spurs ( Fig. 2a ) foliaceous, outer spur as long as first 3 tarsomeres, inner spur slightly shorter; outer spur with straight inner edge, outer edge angulate at apical 2/3, narrowed to rounded apex, inner spur with inner edge straight, outer edge evenly rounded to narrow basal stalk (basal 1/4 of spur). Male genitalia ( Fig. 3 ) quite similar to that of Aegialia opifex Horn (Gordon and Cartwright 1988, fig. 55), with a few sclerites near the base of the internal sac. Apices of parameres less elongate.

Allotype. Generally similar to male except length 4.4 mm, width 2.25 mm; genital plate simple, with 3 or 4 setae ( Fig. 4 ).

Variation. Length 3.8–4.4 mm, greatest width 1.90–2.25 mm. Most specimens in the type series exhibit coloration similar to the holotype, with variation seen in the extent of the light lateral areas on the elytra. In a few specimens, the elytra are nearly uniformly light with darker regions basally, but one specimen, apparently very fresh based on general condition of the integument and the perfect marginal setae on the clypeus, pronotum, and elytra, is almost entirely castaneous dorsally and ventrally, with only the pronotal disk obviously darker.

Type Material. Holotype: IOWA: Lee Co., Shimek State Forest, Lick Creek Unit , 40°36′35″ N - 91°40′16″ W, 27 April 2007, D.A. Veal and J.P. Gruber, sandy banks of Lick Creek ( USNM) . Allotype: IOWA: Lee Co., Shimek State Forest , 2 April 2010, E.L. Freese, sifted sand ( USNM) . Paratypes: 72 specimens, all from Shimek State Forest , same data as holotype (7); same data as holotype except without coordinates, in sandy creek

(b and c redrawn from Gordon and Cartwright 1988); 3) A. shimeki , male genitalia; 4) A. shimeki , female genital plate.

bank, Doug Veal (2); same data as holotype except 40°37′07″ N - 91°40′25″ W, 28 April 2007 (2) ; same data as holotype except 40°37′07″ N - 91°40′25″ W, 28 April 2007 , flood debris in log jam banks of Lick Creek (2); same as holotype except 4 May 2007 (3) ; Shimek State Forest , Lee Co. IA, 6 May 2006 , under debris sandbar, Ed L. Freese (1); same data except 9 May 2007 , sifted sandbar (2); same data except 17 April 2009 (6) ; same data except 4 May 2010 (3) ; same data except 20 May 2011 , sift sandbar (3); same data except 2 April 2012 (2) ; IA: Lee Co. Shimek State Forest , 24 May 2014 , in sandy creek bank, Doug Veal (6); same data except April 2, 2010 (22) ; same data as allotype (8); IOWA: LEE CO. Shimek State Forest , Lick Creek Unit, 170m, 40.610918 -91.671284, sifting sand, 4-V-2007 , MJ Paulsen (3). Paratypes have been deposited in collections of the following: PKL, ELF, Doug Veal (Marion, IA), Robert Gordon (Willow City, ND), William Warner (Chandler, AZ), M.J. Paulsen (Lincoln, NE), Florida State Collection of Arthropods , California Academy of Sciences , University of Nebraska State Museum , and Museo de Storia Naturale e del Territorio (Calci, Italy) .

Etymology. The new species is named in honor of the late University of Iowa zoology, botany, and geology professor, Bohumil Shimek, who influenced the original purchase of acreage in the 1930s and after whom Shimek State Forest was eventually named ( Loehwing 1947).

Discussion. Aegialia shimeki is a member of Aegialia sensu stricto as defined by Gordon and Cartwright (1988) and keys easily to that group in their subgeneric table, although the pronotum is a bit longer than is normal for the subgenus (40% instead of 33% of elytral length). The new species is most similar externally to A. opifex (R. D. Gordon, personal communication), but that species lacks a marginal line on the posterior edge of the pronotum, a feature quite prominent in A. shimeki . Once into the key to species of this subgenus presented by Gordon and Cartwright (1988), proceeding past the second couplet is problematic. The hind tibial spurs are foliaceous, although not comparable in width to the members of the conferta group (couplets 3–8), but they are obviously much broader than those exhibited by the species considered in couplet 9 and beyond. Because of the shape of the spurs, one must proceed to couplet 3 and work through the confertagroup species. Specimens will run to couplet 8, containing Aegialia cartwrighti Stebnicka from South Carolina and Aegialia punctata Brown primarily occurring “west of the Rocky Mountains.” The characters used in this couplet, aside from geographic distribution, involve the distribution of punctures on the pronotum. Like A. cartwrighti , A. shimeki has punctures in the anterior lateral corners, which are absent in A. punctata , but in a few specimens of the new species, the anterior corners appear somewhat rugopunctate making the punctures somewhat difficult to discern. In both A. cartwrighti and A. punctata , however, the outer hind tibial spur is approximately as long as the first three and a half hind tarsomeres and is obviously longer than the inner spur, which is equal to the first three tarsomeres. In A. shimeki , the outer spur is shorter, approximately as long as the first three tarsomeres and nearly equal in length to the inner spur. This character, in conjunction with distribution, should easily distinguish the new species.

Because of the addition of three new species of Aegialia (Aegialia) to the North American fauna since the Gordon and Cartwright (1988) revision appeared, a revised key to the species seems appro- priate. The following key, adapted from Gordon and Cartwright (1988) and Gordon and Rust (1990), should enable identification of the North American members of this subgenus.

KEY TO THE NORTH AMERICAN SPECIES OF AEGIALIA (AEGIALIA)

1. Pronotum with basal marginal line strong, entirely visible (Gordon and Cartwright 1988, fig. 13) .............................................2

1′. Pronotum with basal marginal line absent or interrupted (Gordon and Cartwright 1988, fig. 14) ...........................................17

2. Metatibial spurs broad, foliaceous ( Fig. 2a, b ) ......................................................................... 3

2′. Metatibial spurs slender, somewhat spatulate ( Fig. 2c )............................................. 11

3. Elytral striae feebly impressed, indistinct; apex of body broad, convex; metatibia with single, longitudinal row of tubercles on inner margin; southern California ........................... ............................................. A. convexa Fall

3′. Elytral striae distinctly impressed; apex of body not extremely broad or convex; metatibia with double row of tubercles or scattered tubercles; most of USA and southern Canada........................................................................4

4. Pronotum rugose, impunctate in apical half, remainder of surface indistinctly punctate (Gordon and Cartwright 1988, fig. 24); female genital plate absent ...................................... 5

4′. Pronotum not rugose in apical half, distinctly punctate throughout except punctures sometimes absent near anterior angle; female genital plate present ..................................... 8

5. Apical flange on metafemur reduced (inner angle rounded) (Gordon and Cartwright 1988, fig. 80); New England to Manitoba and New Mexico............. A. conferta Horn

5′. Apical flange on metafemur produced (inner angle abrupt or rounded); Idaho to British Columbia and California ............................6

6. Inner metatibial spur spatulate, tapering apically.....................................................7

6′. Inner metatibial spur truncate apically ( Gordon 1990, fig. 1) .................... A. mcclevei Gordon

7. Apical flange on metafemur strongly produced, inner angle abrupt (Gordon and Cartwright 1988, fig. 81); metatibia slender, subequal in length to femur (Gordon and Cartwright 1988, fig. 81); body elongate-oval............. ..................................... A. nigrella Brown

7′ Apical flange on metafemur moderately produced, inner angle rounded (Gordon and Cartwright 1988, fig. 82); metatibia robust, distinctly shorter than femur (Gordon and Cartwright 1988, fig. 82); body widened apically .......................... ...... A. kelsoi Gordon and Cartwright

8. Apical flange on metafemur strongly produced, inner angle hooked or abruptly angulate (Gordon and Cartwright 1988, figs. 84, 85) ....... A. spinosa Gordon and Cartwright

8′. Apical flange on metafemur not produced, inner angle obsolete (Gordon and Cartwright 1988, fig. 83) ............................................... 9

9. Metatibial spurs dissimilar in length, with outer spur equal to 1 st 3 and a half tarsomeres, and inner spur equal to 1 st 3 tarsomeres ......................................................... 10

9′. Metatibial spurs similar in length, both approximately as long as 1 st 3 tarsomeres; Iowa .......... A. shimeki Lago and Freese , new species

10. Punctation on pronotum extending nearly to anterior angle; South Carolina ..................... ............................. A. cartwrighti Stebnicka

10′. Punctation on pronotum mostly confined to discal area; west of Rocky Mountains ........ ...................................... A. punctata Brown

11. Metatibia without complete obliquely transverse ridge, a single longitudinal row of small tubercles present on inner margin............. 12

11′. Metatibia with at least 1 complete, obliquely transverse ridge, tubercles entirely lacking or only 1 or 2 present..............................13

12. Pronotal surface alutaceous, punctures separated by less than a diameter on disc; Alberta ............... A. carri Gordon and Cartwright

12′. Pronotal surface shiny, polished, punctures separated by more than a diameter on disc; Atlantic and Pacific coasts........................... ..................................... A. blanchardi Horn

13. Color pale red; head smooth, lacking tubercles, granules, or coarse punctation (Gordon and Cartwright 1988, fig. 16) ................14

13′. Color dark brown to nearly black (except A. concinna ); head rough, with coarse granules, punctation, or rugae........................15

14. Color pale red; large, 4.4–5.9 mm long and 2.4–3.2 mm greatest width; protibial teeth rounded, not acutely pointed ....................... ....... A. magnifica Gordon and Cartwright

14′. Color pale yellow-red; small, 3.6–4.5 mm long and 2.1–2.4 mm greatest width; protibial basal and middle teeth acutely pointed ........ ....................... A. knighti Gordon and Rust

15. Elytral intervals flat; average total length 4.5 mm; Nye Co., Nevada ......................... ....... A. crescenta Gordon and Cartwright

15′. Elytral intervals convex; total length never more than 4.0 mm; California, North Dakota .................................................................... 16

16. Head roughly granulate with some coarse punctation; California .................................. ....... A. concinna Gordon and Cartwright

16′. Head rugose, without punctation; North Dakota ............. A. amplipunctata Gordon and Cartwright

17. Metatibial spurs foliaceous .......................... ............................................ A. opifex Horn

17′. Metatibial spurs slender, somewhat spatulate (Gordon and Cartwright 1988, fig. 70)..................................................................18

18. Pronotum nearly impunctate (some fine, indistinct punctures may be apparent on disc)...... .................................. A. arenaria (Fabricius)

18′. Pronotum coarsely punctate.....................19

19. Metatibia with complete, strong ridge at apical 2/3 (Gordon and Cartwright 1988, fig. 73) .......... A. hardyi Gordon and Cartwright

19′. Metatibia without complete ridge............20

20. Pronotum densely, coarsely punctate throughout ......................................... A. latispina LeConte

20′. Pronotum lacking punctures anteriorly and laterally, or punctures, if present, fine and indistinct ......................... A. crassa LeConte

Figures

Fig. 1. Aegialia shimeki, habitus.

Figs. 2–4. Morphology of Aegialia species. 2) Metatibial spurs of a) A. shimeki, b) A. conferta, c) A. blanchardi