Griburius rileyi, Sassi, 2023

Sassi, Davide, 2023, Revision of the Griburius scutellaris (Fabricius, 1801) species group (Coleoptera: Chrysomelidae: Cryptocephalinae), Zootaxa 5315 (6), pp. 501-548 : 536-540

Griburius rileyi sp. nov.

( Figs 10 ; 13e )

Griburius sp. Riley et al., 2001: 11.

Types. Holotype: ♁, body, aedeagus and detached abdomen glued on the same card, // “Tex: Aransas Co. Goose Is. St. Pk VI-7-83: D. Rider & C. B. Barr” [white label, printed] // [circular pink disc] // “ Griburius rileyi sp. nov. HOLOTYPUS D. Sassi des.” [red label, printed] // ( TAMU) . PARATYPES (212 specimens): U.S.A.: LOUISIANA: Caddo Par.: Shreveport City Park 27.VI.1987 (1, DSPC) ; Calcasieu Par. : 3.5 mi S Jct. 90 397 nr Lk. Charles 20.VI.1981 (2, ERPC) . Cameron Par.: 5 mi E Cameron 20.VI.1981 (11, TAMU & MSNG) ; Holly Beach 20.VI.1981 (1, ERPC) ; Lake Clayborne St. Pk. 6.VI.1983 (1, ERPC) . Claiborne Par.: Lake Claiborne St. Pk. 6.VII.1983 (1, ERPC) . Natchitoches Par.: Kisatchie Nat. For. Red Bluff Campgrd. 21.VI.1984 (3, ERPC) ; Kis. Nat. For. Red Dirt W.M.A. 20.VI.1986 (1, ERPC) . [Rapides Par.]: Alexandria 31.VI.1945 (1, BYU) . Red River Par.: 5 mi N Coushatta 27.VI.1987 (1, ERPC) ; [St.] Landry Par.: Washington 4.VI.1981 (1, ERPC) . TEXAS: “ Dallas ” (1, MNHUB) . Angelina Co. : Upland Island Wilderness Ar. 3 mi NNE Rockland 19.VII.1993 (2, TAMU) ; Anzalduas Co.: Anzalduas Co. Pk. 28.VII.1991 (1, TAMU) . Bandera Co.: Bandera 13.VI.1982 (1, TAMU) . [Bastrop Co.]: Bastrop St. Pk. at light 24.IV.1962 (1, TAMU) . Bell Co.: Temple USDA Lab. Nursery reared from pupal case attached to bark of Tamarix aphylla 9.VI.2009 (2, TAMU) ; Temple 27.VI.2003 & 29.VI.2006 & 17.VII.2006 & 2.VIII.2006 & 13.VII.2007 (7, TAMU) . Bexar Co.: Ft Sam Houston 14.VI.1952 (1, BYU) ; Hwy. 1604 nr Hwy 10 26.VII.1977 (1, ERPC) . Brazos Co.: College Station 4.VII.1970 (1, TAMU) . Brooks Co.: 9–10 mi S Falfurrias 8–9.V.1989 (3, TAMU) ; Rt. 281 7.3 mi S Falfurrias (rest stop) 12.V.2010 (1, BYU) . Burleson Co.: Somerville Lake St. Pk. SW of Lyons RR 57 16.VI.1989 (1, BYU) . Cameron Co.: Sabal Palm Grove Sanct. 6–7.V.1991 & 26–27.VII.1991 (4, TAMU) ; Sabal Palm Grove Audubon Reserve 26–29.V.1979 (1, FIMU) ; Sabal Palm Grove Sanct. Nr Southmost 18.V.1979 (1, ERPC) ; Boca Chica 27.VII.1961 (1, TAMU) ; Boca Chica Beach 4.IV.1987 (1, ( ERPC) ; 2 mi W Boca Chica Beach 7.V.1991 (3, TAMU) ; 7.6 mi W Boca Chica Beach 7.V.1991 (1, TAMU) ; Brownsville 12–14.VI. & 21.VI. & 26.VI.1969 & 10.VI.1970 (4, TAMU) ; Brownsville White Wing Dove Res. 9.VI.1970 (1, TAMU) ; 9 mi NE Brownsville on Hwy 48 6.V.1989 (7, TAMU, MSNM, DSPC) ; 14 mi & 9 mi NE Brownsville 30.III.1986 & 18.V.1979 (3, ERPC) ; Palmito Battle Field 26.V.1971 (1, TAMU) ; Palmito Hill E of Brownsville 5.V.1989 (2, TAMU) ; 14 mi NE Brownsville 30.III.1986 (1, ERPC) ; “ Ebony Loma ” 12.5 mi E Brownsville 5.V.1989 (1, TAMU) ; Las Palomas Reserve Brownsville 22.VI.1969 (1, TAMU) ; Rt. 100 5 mi W Port Isabel 12.IV.2009 (3, BYU) ; 6 mi SW Port Isabel 8.V.1991 (2, TAMU) ; Hwy 48 8 mi SW Port Isabel 11.V.1910 (2, TAMU) ; 10 mi. E Brownsville on Hwy 4 6.V.1999 (1, BYU) ; LRGVNWR Loma Unit Massey Way ( Rd. ) 16.V.2010 (2, TAMU) ; Laguna Atascosa Natl. Wdlf. Refuge ( Unit 7) 4.V.1989 (6, TAMU & DSPC) . Dewitt Co.: 10 mi ENE Cuero 14.VI:2001 (2, TAMU) . Duval Co.: La Mariposa Ranch 3 mi & 3.5 mi S Realitos 22–23.IV.2005 (6, TAMU) . Erath Co.: FM 1188 3 mi W Bluffdale Malaise trap 22–29.VII.1976 (1, TAMU) ; Frio Co.: Hwy 57 3 mi S Moore 2.V.1989 (1, BYU) . Galveston Co.: Jamaica Beach VIII.2003 (1, ERPC) ; Galveston Is. Jamaica Beach 14.VII.1980 (2, TAMU) . Goliad Co.: 12 mi W Kenedy 12.V.1978 (1, FIMU) . [ Guadalupe Co.]: Seguin 26.V.1933 (1, TAMU) . Hardin Co.: 1 km N Jct. FM 122 et FM 92 23.VI. 1989 (1, TAMU) . Harris Co.: W Houston Airport 26.VI.1994 (1, TAMU) ; Baytown 5.VI.1996 (1, MSNG) . [Hays Co.]: 8 mi W Dripping Springs 11.VI.1961 (2, TAMU) . Hidalgo Co.: Hidalgo Co. IV.1932 (1, TAMU) ; Hidalgo Co. 29.V.1934 (1, TAMU) ; Hidalgo Co. 123 [a single specimen bears the further label: “ Donna 24.IX.1933 ”] (18, TAMU) ; Donna 7.V. & 10.V. & 11.V. 4.VI.1933 (8, TAMU) . Jim Hogg Co.: 19 mi SW Hebbronville 10.IV.1982 (1, ERPC) . Jim Wells Co.: 9 mi W Ben Bolt 12.IV.2004 (1, TAMU) ; 1 mi N Premont 8.IV.1971 & 22.V.1973 (2, TAMU) . Kenedy Co.: 5.8 mi S Sarita 3.V.1989 (10, TAMU) ; 3 mi N Norias 4.V.1989 (1, TAMU) ; Armstrong 16.V.1984 (4, TAMU) ; 4 mi S Armstrong 11.VI.1969 (12, TAMU) ; Kenedy Ranch Jaboncillos Pasture San Pedro Camp 21.IV.2001 (3, TAMU) ; Kenedy Ranch Jaboncillos Pasture sand dune area 21.IV.2001 (1, TAMU) ; Kenedy Ranch Jaboncillos Pasture Cayo Grande 21.IV.2001 (1, TAMU) . Kerr Co.: Kerville 18.VII.1981 (1, TAMU) . Kleberg Co.: 25.5 mi S Sarita 10.V.2010 (1, BYU) ; Riviera Beach 3.V.1989 (1, TAMU) ; Riviera Beach 23.V.1989 (1, BYU) ; 3 mi E Ricardo 4.XI.2003 adult em. 10.V.2004 reared from larva taken on live stem of Tamarix sp. Larva fed upon bark and old foliage (1, TAMU) . Live Oak Co.: 2.5 mi SSE Dinero (Site 9) Twin Oaks ranch 21.IV.2007 (1, ERPC) . Matagorda Co.: 2 mi SE Blessing 29.V.1988 (2, FIMU) . McMullen Co.: Choke Canyon State Park at the Calliham Unit 27.IV.1988 (1, BYU) . Nueces Co.: Sandia 27.IV.1969 (2, TAMU) ; Sabine Co.: Sabine Natl. Forest 2.9 mi S Yellowpine 29.VII.1975 (1, TAMU) . San Patricio Co.: 2 mi S Sinton 10.VI.1971 (1, TAMU) ; Welder Wildlife Ref. 27.VI.1969 (2, TAMU) ; Mathis 4.VI.1964 (1, TAMU) ; Lake Corpus Christi State Park 8.VI.1969 (1, TAMU) ; Uvalde Co.: 4 mi E Concan 31.V.1979 (1, FIMU) . [Williamson Co.]: Taylor 7 & 15.VI.1929 (2, TAMU) . All the specimens listed above were labelled: // “ Griburius rileyi sp. nov. PARATYPUS D. Sassi des.” [red label, printed]. Additionally, two further specimens housed in MNHUB, one male and one female, previously described and labelled as paratypes of Griburius decoratus (see above for a detailed discussion), have also been designated as paratypes of the new species.

Type locality. Goose Island State Park (Aransas County, Texas, U.S. A).

Etymology. The species is dedicated to Edward G. Riley, specialist in Chrysomelidae , who collected most of the specimens of this new species and kindly allowed me to describe the taxon.

Additional material examined. ALABAMA: Shelby Co.: Oak Mountain State Park 28.VI.2022 (1, GBIF) ; Shoal Creek Park 22.VII.2021 (1, GBIF) ; Wilcox Co.: Alberta 27.VIII.2022 (1, GBIF) . MISSISSIPPI: Jones Co.: Jones Co. V.2022 (1, GBIF) . OKLAHOMA: McCurtain Co.: McCurtain Co. 12.VII.2020 (1, GBIF) .

Additional data from literature. The new species had already been pointed out by North American entomologists, but never described. In particular, Riley et al. (2001) wrote: “[…] Another yet undetermined Griburius species which is similar in appearance [to Griburius larvatus ] is common in southern Texas and reaches eastward to Louisiana ”. I had the opportunity to examine most of the specimens studied and annotated by Edward Riley. Rouse & Medvedev (1972) reported a Griburius species identified as G. larvatus from Arkansas (Washington County and Crawford County). However, I am almost sure it should be ascribed to G. rileyi .

Distribution. U.S.A.: Alabama, Arkansas?, Louisiana, Mississippi, Oklahoma, Texas.

Diagnosis. The most morphologically similar species are G. decoratus and G. larvatus . The new species is distinguished from G. decoratus by the shape and size of the spots on the disc of the pronotum, which are generally drop-shaped, with the narrowest extremity directed downwards and towards the midline, and never reach the pronotal margins. In G. decoratus these spots are often angular in shape and frequently reach the anterior and posterior margin. Additionally, in G. rileyi the elytral spots are generally rounded and distinct from each other, with no tendency towards transverse fusion. In particular, the central postmedian elytral spot is never in contact with the margin or the suture. In most cases of G. decoratus the elytral spots form two transverse bands (basal and postmedian). Even in the lighter forms (for example in some examples from San Luis Potosi, at first glance very similar to G. rileyi ), the central postmedian spot is transverse (not rounded) and usually makes contact with the elytral margin. However, specimens of G. decoratus have been observed with a remarkable light colour, with dorsal black spots very small, rounded and well separate from each other, and at times even missing. In this case, the distinction with G. rileyi on the basis of the colour pattern is not easy and the analysis of the median lobe is recommended. In G. larvatus the dorsal black spots are generally smaller, often the two pronotal spots are rounded or punctiform or totally missing. Furthermore, the two elytral spots along the suture are almost always missing, even when the black pattern is well developed. Conversely, these two sutural spots are almost always clearly visible in G. rileyi , and this constitutes a good diagnostic element. However, it should be noted that some specimens of G. larvatus , collected in southern-most Florida (Dade and Monroe counties), have a decidedly greater development in the black elytral design, in this case a tendency can be observed for a coalescence of the internal basal elytral spot with a well-developed anterior sutural spot, forming a vaguely U-shaped design on the elytra ( Fig. 7f ). In these specimens, the posterior sutural spot may also be present, which tends to form a rather fuzzy transverse band, with the central elytral spot. The pattern is quite different in G. rileyi , in which the sutural spots are always well separated from the others. G. rileyi is also distinguished from G. decoratus by the shape of the aedeagal median lobe: in the former species the sides of the apex are more sloping, thus forming a more open angle with the profile of the aedeagal tube. The apical denticle is also more rectilinear, while it is slightly bent in the dorsal direction in G. decoratus . In G. larvatus the ventral profile of the median lobe is quite different, and the sides of the apex form an even more open angle with the profile of the aedeagal tube.

Description of male. Habitus in Fig. 10a–b (HT). BL = 4.3–4.7 mm, BW = 2.6–2.9 mm, PL = 1.7–1.9 mm, PW = 2.4–2.6 mm. Interocular distance 4.7–6.4 % of BL.

Head ( Fig. 10d ) yellow, usually with vertex, lower rim of clypeus, insertion of antennae and upper part of ocular lines black or brownish. Labrum yellow. Vertex bright, sparsely and shallowly punctured with very short, recumbent, whitish setae. Surface of frontoclypeal area bright as well, with shallow, irregularly scattered punctation and sparse short setae. Mid-cranial suture well detectable on vertex and between upper lobes of eyes. Upper lobes of eyes well separated from each other along midline. Ocular lines very weakly impressed but discernible because dark coloured against light background, strictly adhering to ocular rim up to ocular canthus. Ocular canthus large not differentiated in punctation and setosity from the remainder of frontoclypeal surface.Antennae ( Fig. 10m ) rather short with antennomeres 3–5 yellow, bright, subcylindrical; antennomeres 6–11 brownish, dull, more flattened and more diffusedly setose.

Pronotum yellow with two drop-shaped black spots on disc. Pointed end of black spots directed towards median portion of posterior margin, opposite rounded end never reaching anterior margin. Small, linear dark line almost always distinguishable near posterior margin just in front of scutellum. Sometimes further black markings at bottom of posterolateral impressions. Quite rarely these latter markings fused with drop-shaped ones to form bilobed black pattern. Dark pattern at times partly brownish rather than black. Pronotal shape roughly elliptical, scarcely transverse, regularly convex on disc. Lateral margins narrow, not visible from above, regularly curved so that maximum width nearly at middle. Surface moderately shiny usually with scattered, fine punctation at middle of disc. Punctures coarser and more deeply impressed along sides and in proximity of posterolateral impressions. Sometimes punctation on central part of disc almost obliterated. Posterolateral impressions well impressed and obliquely arranged, marked at bottom of depression by some strong punctures. Pronotal posterior margin thickened along posterolateral impressions.

Scutellum yellow, subtriangular with apex shortly truncated. Surface minutely and sparsely punctured, with few, very short setae.

Elytron yellow with five black spots. First one on humeral callus; second one close to basal margin, generally delimited by first and fourth rows of punctures; third spot just behind midline, usually delimited by fourth and seventh rows of punctures; fourth spot on suture, behind postscutellar area; fifth one on suture as well, just before apical clivus. Lateral margin and suture, with exception of basal ends, narrowly black as well. Bottom of elytral punctures darker than surrounding area. Epipleuron light yellow. Elytral outline short with sides almost straight and convergent posteriorly. Lateral margins narrow, simultaneously visible from above only along posterior half. Elytral surface slightly flattened on disc, moderately shiny, with strong punctation arranged in almost regular rows, distinct up to posterior clivus. Intervals flat. Postscutellar area fairly raised. Humeral callus prominent, impunctate. Epipleuron smooth, impunctate, with convex surface.

Pygidium yellow. Surface covered with close shallow punctures and appressed, pale setae.

Ventral parts of thorax usually black with more or less extended yellow patches on hypomera, mesepimera, metasternum and prosternal process. Abdominal ventrites mostly yellow, only median part of ventrites 1–4 more or less extensively black or brownish. Hypomera, mesepimera and mesepisterna almost bare, shiny, with coarse, well-impressed, scattered punctures. Remainder of ventral surface of thorax rather shiny as well, covered with fine punctures and regularly distributed, sparse, whitish setae. Prosternal process large, with sides almost straight between anterior coxae, then converging in large, round apex; surface feebly depressed at center, covered with coarse, shallow punctures and sparse, long, semi-erect setae. Legs yellow, sometimes tarsi slightly darkened.

Median depression on fifth abdominal ventrite very shallow and hardly detectable, but with fewer setae and punctures than remainder of ventrite surface.Ventrite posterior margin very slightly notched.Median lobe of aedeagus ( Fig. 10g –k ) with apex rather long, triangular, terminated with blunt median denticle. Ventral outline marked with low carina. Setose depressions shallow, weakly delimited, with surface covered by very small punctures and arcuate setae.

Female. BL = 4.1–5.7 mm, BW = 2.6–3.7 mm, PL = 1.5–2.0 mm, PW = 2.3–3.2 mm. Interocular distance 9.8–10.5 % of BL.

Females are larger with eyes ( Fig. 10c ) smaller and more separated along midline. The head is black with evident yellow “eyebrows” along the upper margin of eyes. Besides, a transverse winding ribbon-like yellow band between ocular canthi is detectable. Seldom is the frontoclypeal area totally yellow.

The fifth abdominal ventrite in females has a large, rounded and deep pit. The bottom of the pit is brownish (while the remainder of the ventrite is yellow), glabrous, matt, impunctate but covered by tiny wrinkles. The vasculum of the spermatheca ( Fig. 10n ) is scarcely pigmented, sickle-shaped with slightly swollen, short proximal lobe. The distal lobe is long, slender, tapered with a rather acute apex mildly bent downwards. The ampulla is not pigmented, lengthened. The duct insertion on the ampulla is simple, very short and not pigmented. The sperm gland insertion is longer and bent upwards. The duct is uniform in size, slender, quite rigid, not coiled but with 2–5 very loose turns close to the vasculum. The insertion on the bursa copulatrix is simple, neither swollen nor pigmented.

Remarks. In the collection of SDEI I tracked down a male specimen coming from the ancient Haag collection, labelled: “ Mexico Kraatz” [white label, handwritten] // “Coll. Haag” [White label, printed] // DEI Munchenberg Col – 14386” [green label, printed], which belongs without doubt to G. rileyi sp. nov. and, consequently, here designated as paratype of the new species and labelled: // “ Griburius rileyi sp. nov. PARATYPUS D. Sassi des.” [red label, printed]. That would suggest the presence of this species in Mexico. Nonetheless, this datum must be considered highly questionable, since it is possible that the specimen might have been collected in Texan territory when Texas still belonged to Mexico. For this reason, although, given its wide diffusion in Texas, the presence of this species at least in northern Mexico is very likely, more convincing confirmations for Mexico are necessary.

Figures

FIGURE 7. G. larvatus. a–b: habitus, dorsal and lateral view (LT); c: frontal view, female (LT); d: frontal view, male (Big Pine Key, Florida).; e–f: colour variations (e: male, Big Pine Key, Florida; f: female, Long Pine Key Campground, Florida).; g–k: median lobe of aedeagus in ventral (g), dorsal (h) and lateral (k) view [0.6 mm]; m: antenna [1.1 mm]; n: spermatheca [0.4 mm]; p: original label of the LT. hd: setose depressions. Square brackets: length of scale segment.

FIGURE 10. G. rileyi. a–b: habitus, dorsal and lateral view (HT); c: frontal view, female (Boca Chica Beach, Texas); d: frontal view, male (HT); e–f: colour variations (e: Blessing, Texas; f: Hidalgo Co. Texas); g–k: median lobe of aedeagus in ventral (g), dorsal (h) and lateral (k) view [0.7 mm]; m: antenna [1.2 mm]; n: spermatheca [0.4 mm]. hd: setose depressions; asu: additional sutural spot. Square brackets: length of scale segment.

FIGURE 13. Distribution maps for the Griburius scutellaris species-group. a: G. lecontii, Mexican range; b: G. lecontii, U. S. range; c: G. montezuma, Mexican and Central American range; d: G. montezuma, U. S. range; e: G. rileyi; f: G. scutellaris. Black markings: data from specimens analyzed during the study. Red markings: data from the public database Global Biodiversity Information Facility (GBIF.com) or literature data. Black stars: the presence in the state is reported in the consulted literature, but without more precise data on the location.