Griburius larvatus (Newman, 1840)

Sassi, Davide, 2023, Revision of the Griburius scutellaris (Fabricius, 1801) species group (Coleoptera: Chrysomelidae: Cryptocephalinae), Zootaxa 5315 (6), pp. 501-548 : 525-529

Griburius larvatus (Newman, 1840)

( Figs 1d–e ; 7 ; 12f )

Cryptocephalus larvatus Newman, 1840: 250 (original description).

Scolochrus larvatus: Suffrian 1852: 124 (as syn. of Griburius equestris Olivier, 1808 , taxonomic notes); Suffrian 1858: 390 (as species resurrected from Griburius equestris , taxonomic notes).

Scolochrus decoratus larvatus: Jacoby 1880: 61 (taxonomic notes).

Griburius larvatus: Crotch, 1873a: 32 (taxonomic notes); Crotch, 1873b: 96 (catalogue); Clavareau, 1913: 90 (catalogue); Blackwelder, 1946: 640 (catalogue); Riley et al.: 2001: 11 (taxonomic notes); Riley et al., 2003: 154 (catalogue); Clark et al., 2004: 138 (biological notes).

Types. In his very short description Newman (1840) did not mention the number of the specimens available to him. A single specimen, female, pinned, is present in BMNH bearing the following labels: // “E. Doubleday. St. John’s [sic] Bluff, E. Florida.” [white label, printed] // “Named by Suffr.” [white label, handwritten] // “Baly Coll.” [white label, printed] // “ Scolochrus larvatus Newman N : America” [white label, handwritten] //. According to the valuable information provided by Michael Geiser and Max Barclay, the first printed label ( Fig. 7p ) is very characteristic and present on many other Newman’s types in the BMNH collections. Even though Newman’s own collection and type material came to be dispersed, most of the material eventually ended up at BMNH, via some of Newman’s colleagues (such as F. Walker and H. Clark). This specimen was evidently acquired by Baly who, rather confusingly, then sent it out to Suffrian for his revision ( Suffrian, 1852). That’s the reason of the label: “named by Suffr.”. Therefore, it is possible that Baly had himself received it from Newman, but didn’t notice it was a type, and neither did Suffrian, nor, until now, any of the curators of BMNH. The specimen and locality label match exactly with the description, and the style of the label is the same as with other Newman species described from the same material. This is good evidence that it belongs to the type series and therefore it is here designed as lectotype of the species. The following label was added to the specimen: “ Griburius larvatus (Newman, 1840) ( Cryptocephalus larvatus ) LECTOTYPUS D. Sassi des.” [red label, printed] // (BMNH).

Type locality. St. Johns Bluff (Duval County, Florida, U.S.A.)

Additional material examined. U.S.A.: FLORIDA: Alachua Co.: Hammock Preserve State Park 11.VI.2013 (1, GBIF) ; Gainesville 26.IV.2020 (1, GBIF) . Brevard Co.: Cocoa beach 10.V.2018 (1, GBIF) . Broward Co.: Hollywood Beach (2, BMNH) . Charlotte Co.: Punta Gorda 9.IV.1952 & 10.V.2009 (3, BYU & DSPC) ; North Port Hwy 41 Toledo Blade Blvd 16.IV.1989 ( ERPC) . Clay Co.: Gold Head Branch St. Pk 28.V.1991 (1, TAMU) . Collier Co.: Marco Is. Tigertail Beach County Park 18.IV.1995 (3, BYU) ; Naples 20.V.2000 (1, MSNG) . Columbia Co.: Highsprings 24.IV.2022 (1, GBIF) . Hamilton Co.: Jasper 1.VII.1990 (1, BYU) . Hendry Co.: La Belle 21.IV.1967 (1, ZSM) . Highlands Co.: Archbold Biol. Station 14–15.IV.2010 (11, BYU) ; Archbold Biol. Station 25.VI.2001 (1, BYU) ; Archbold Biol. Station 15.IV.1980 (8, FIMU) ; Archbold Biol. Station Venus 17.V.2015 (1, BMNH) ; Archbold Biol. Station Lake Placid 21.V.1967 (1, ZSM) ; 3 mi S Sebring 30.IV.1985 (1, FSCA) ; Venus IV.1958 (2, NHMB) . Hillsborough Co.: Tampa Mac Dill Field IV–V.1943 (7, FIMU) . Indian River Co.: Vero Beach 29.IV.1988 (2, ERPC) . Lake Co.: 5 mi S Leesborg 30.VI.1980 (1, ERPC) . Lee Co.: Fort Myers 15.IV–3.VI.1967 (34, ZSM) ; Leheigh [sic] 10–15.IV.1977 (12, FIMU) ; Lehigh Acres 17.IV.1982 (2, FIMU) ; Tice 1.IV.1997 (1, BYU) . Levy Co.: 5.IX.1983 (2, FIMU) ; 25 mi SW Alachua Co. line on rt 24 28.VI.1991 (1, FSCA) ; 8 mi NW Bronson 29.VIII.1984 (1, FIMU) . Manatee Co.: Ana Maria 17.VII.1933 (2, TAMU & FIMU) ; Ellenton 28.VII.1996 (1, BYU) . Marion Co.: Ocala Nat. Forest 3 mi N Hwy 40 at Zay Prairie 20.V.1976 (1, MSNG) ; 11.6 mi SE Belleview 16.V.1977 (1, MSNG) . Martin Co.: Hobe Sound NWR 1.X.2022 (1, GBIF) . Miami-Dade Co.: Everglades Nat. Pk. Long Pine Key Campground 11.V.1990 (7, TAMU) ; Everglades Nat. Pk. Pinelands trail 12.V.1990 (1, TAMU) ; Florida City 20.IV.1985 (1, BYU) ; Pinelands nr. Florida City 17.VI.1977 (1, ERPC) ; Everglades Nat. Pk. nr Royal Palm Hammock 10.V.1990 (1, TAMU) ; Deering Estate Park 7.V.1990 (3, TAMU) ; Chekika St. Pk. 9.V.1990 (2, TAMU) ; Matheson Hammock Park 8.V.1990 (2, TAMU) ; Old Cutler Hammock 9.V.1990 (11, TAMU) . Monroe Co.: Big Pine Key 13–20.V.1990 partly beating at night (29, TAMU) ; Big Pine Key N end Key Deer Blv. 19.V.1990 (1, TAMU) ; Big Pine Key 2.V.1988 (2, ERPC) ; Big Pine Key 23–27.1984 (5, ERPC) ; Big Pine Key 29.III.1979 (1, ERPC) ; Big Pine Key 10.V.1974 (1, FIMU) ; Big Pine Key 20.VI.2001 (3, TAMU) ; Lower Matecumbe Key 24.VII.1984 (5, ERPC) ; Cudjoe Key 19.V.1990 (5, TAMU) ; Sugarloaf Key (NE corner) 16–18.V.1990 (4, TAMU) ; No Name Key 18.V.1990 (1, TAMU) ; Grassy Key 23.VII.1977 (1, ERPC) ; Grassy Key 10.VI.1976 (1, FIMU) ; Bahia Honda Key 23.VII.1984 (1, ERPC) ; Upper Key Largo 6.VI.1994 (6, BYU) ; Key Largo 8.IX.1983 (1, BYU) ; Fleming Key 22.V.1979 (1, FSCA) ; Everglades Nat. Pk. 13.V.1977 (1, ERPC) . Okeechobee Co.: Everglades HNWRCA 23.V.2022 (1, GBIF) . Orange Co.: 3 mi E Winter Park 29.III.1976 (3, ERPC) . Osceola Co.: St Cloud 15.V.2019 (1, GBIF) . Palm Beach Co.: Boca Raton 7.VII.2022 (1, GBIF) . Pasco Co.: Pasco County, V.2022 (1, GBIF) . Pinellas Co.: Clearwater IV–V.1943 (6, FIMU) ; Fort DeSoto County Park 7.VI.2000 (1, BYU) . Polk Co.: Frostproof 16.V.2020 (1, GBIF) . Sarasota Co.: 2 mi E Venice 8.IV.1994 (2, BYU) ; North Port IV.1993 & IV.1995 & IV.1997 (8, BYU) ; Laurel IV.1993 & IV.1995 & IV.1997 (8, BYU) ; Carlton Memorial Reserve 2.IV.1997 (1, BYU) ; Myakka River State Park 14.IV.1993 (1, BYU) . Seminole Co.: Longwood 12.V.2000 (1, BYU) . Volusia Co.: Daytona Beach 27.V.1967 (1, ZSM) . GEORGIA: “Georgia” (2, NHMB & ZSM) . Liberty Co.: Saint Catherines Island 27.V.1978 (1, BYU) . Screven Co.: Newington 8.V.2022 (1, GBIF) .

Additional data from literature. Due to the nomenclatorial confusion that persisted until the very appropriate clarification by Riley et al. (2001), the literature data must be taken with caution. Consequently, specimens identified as G. larvatus from Ohio ( Wilcox, 1954) should probably be treated as light forms of G. scutellaris , and the record from Arkansas by Rouse & Medvedev (1972) probably belongs to G. rileyi n. sp.

Distribution. U.S.A.: Florida, Georgia.

Diagnosis. The species with the most similar dorsal colouration is G. rileyi , which is also the taxon whose range, along its eastern border potentially overlaps that of G. larvatus , even though there is no evidence of such overlap at present. A useful aspect in distinguishing the two species is usually the absence, in G. larvatus , of the two sutural black spots, which are almost always well developed in G. rileyi . However, in specimens from some apparently circumscribed sections of G. larvatus range, these spots may be present, but in this case, the anterior one tends to coalesce with the internal basal spot, and the posterior one with the central elytral spot ( Fig.7f ). Such tendency towards fusion is not observable in G. rileyi . However, given the great chromatic variability, the most reliable distinction is given by the examination of the median lobe of the aedeagus.

Description of male. BL = 4.4–5.0 mm, BW = 1.7–3.2 mm, PL = 1.7–1.8 mm, PW = 2.5–2.8 mm. Interocular distance 6.0–6.8 % of BL.

Head ( Fig. 7d ) 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 punctation above all along ocular rims and scattered very 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 narrow, marked by row of punctures, 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. 7m ) rather short with antennomeres 3–5 yellowish, bright, subcylindrical; antennomeres 6–11 progressively darkened, dull, more flattened and more diffusedly setose.

Pronotum yellow, at times shaded of slightly darker, blurred markings. Two drop-shaped black spots on disc, sometimes reduced to small, rounded markings, or black pattern extended to posterior margins thereby delimiting anchor-shaped yellow area at center of disc. Pronotal shape roughly elliptical, scarcely transverse, only weakly flattened 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. Discal punctation may be stronger and denser, often in specimens with more extended black pattern. Posterolateral impressions well distinguishable 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 three small, rounded spots, first on humeral callus, second close to basal margin between first and fourth rows of punctures, third spot just behind midline between fourth and fifth rows of punctures. Lateral margin and suture, with exception of postscutellar area, narrowly black as well. Bottom of elytral punctures darker than surrounding area. Epipleuron 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, sometimes with blurred, darker patch at center. Surface matt, covered with close shallow punctures and appressed, pale setae.

Ventral parts of thorax usually black with 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, scattered punctures. Remainder of ventral surface of thorax rather shiny as well, covered with well-impressed 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 straight. Median lobe of aedeagus ( Fig. 7g –k ) with apex rather long, triangular, terminated with blunt median denticle. Ventral outline marked with raised, regularly curved carina. Setose depressions short, shallow, weakly delimited, with surface covered by very small punctures and long arcuate setae.

Female. Habitus in Fig. 7a–b (LT). BL = 5.1–5.7 mm, BW = 3.3–3.7 mm, PL = 1.9–2.0 mm, PW = 2.8–3.2 mm. Interocular distance 11.8–12.3 % of BL.

Females are larger with eyes ( Fig. 7c ) smaller and more separated along midline. The dark (brownish) pattern is generally more extended on the head surface. Sometimes the elytral inner black spot along basal margin is obliquely connected to suture.

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. 7n ) is scarcely pigmented, sickle-shaped with a slightly swollen proximal lobe. The distal lobe is long, slender, tapered with a rather blunt apex mildly bent downwards. The ampulla is not pigmented, lengthened. The duct insertion on the ampulla is simple, short and not pigmented. The sperm gland insertion is long and arched upwards. The duct is uniform in size, slender, quite rigid, not coiled but with a series of 4–5 turns (sometimes reduced to a single turn) close to the vasculum. The insertion on the bursa copulatrix is simple, neither swollen nor pigmented.

Figures

FIGURE 1. Median lobe of aedeagus with everted endophallus. a: G. scutellaris, lateral view (Wiggins, Missouri); b: G. albilabris, lateral view (Nayarit, Mexico); c: G. decoratus, lateral view (Melinda, Belize); d: G. larvatus, lateral view (Big Pine Key, Florida); e: G. larvatus, dorsal view (Big Pine Key, Florida). as: anterior sclerite; ps: posterior sclerite; ds: dorsal side of median lobe. Dissections and photos thanks to the courtesy of M. Bollino (Lecce).

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 12. Distribution maps for the Griburius scutellaris species-group. a: G. albilabris; b: G. biverrucatus; c: G. boucardi; d: G. decoratus; e: G. errans; f: G. larvatus. Black markings: data from specimens analyzed during the study. Red markings: data from the public database Global Biodiversity Information Facility (GBIF.com).