Griburius equestris ( Olivier, 1808 )

Sassi, Davide, 2023, Five new species of the genus Griburius Haldeman from Central America (Coleoptera: Chrysomelidae, Cryptocephalinae), Fragmenta entomologica (Deerfield Beach, Fla.) 55 (1), pp. 117-138 : 134-135

Griburius equestris ( Olivier, 1808)

( Figs 6 , 9a )

Cryptocephalus equestris Olivier, 1808: 804 ; Suffrian, 1852: 122 [ Scolochrus ] (taxonomic notes); Suffrian, 1858: 389 [ Scolochrus ] (taxonomic notes); Jacoby, 1889: 134 [ Scolochrus ] (taxonomic notes, misidentification); Clavareau, 1913: 89 [ Griburius ] (catalogue); Blackwelder, 1946: 639 [ Griburius ] (catalogue); Riley et al., 2001: 11 [ Griburius ] (taxonomic notes); Chamorro, 2013: fig. 15 [ Griburius ] (taxonomic notes, misidentification); Ordóñez-Reséndiz & López-Pérez, 2021: 91 [ Griburius ] (catalogue, misidentification).

Types. The types of this species were carefully looked for in MNHN in Paris, but unsuccessfully. Unwillingly, they must be considered, as many of Olivier’s types, permanently missing. Luckily, Olivier published a small but clear enough drawing of a studied specimen. Probably based on this drawing, Suffrian (1858) was able, correcting a previous misinterpretation ( Suffrian 1852), to track down and describe a specimen perfectly corresponding to Olivier’s idea in the BMNH collection. Despite this, the species has long been confused (see above in the previous paragraph) in publications and collections, with other similar species, such as Griburius larvatus (Newman, 1840) (see for instance Sassi, in press). For this reason, in order to define the meaning of the species in a stable way, the designation of a neotype is proposed here, choosing the specimen studied by Suffrian and still preserved at the BMNH. NEOTYPE: f#, pinned, genitalia not studied, // “ Scolochrus equestris Oliv : N: America.” [white label, handwritten] // “Type Suffr: Coll: Deyrolle [white label, handwritten] // “Baly Coll.” [white label, printed] // “ Griburius equestris ( Olivier, 1808) ( Cryptocephalus equestris ) NEOTYPUS D. Sassi des.” [red label, printed] // (BMNH).

Type locality. “Nord America”

Additional material examined. U.S.A., FLORIDA, Alachua Co.: Gainesville 14.III.1982 (2, USNMNH) ; Gainesville 10.X.1985 (1, FIMU) ; Sugarfoot Gainesville 20.III.2022 (1, GBIF) . Hernando Co.: Inverness 3.V.1980 (1, USNMNH) . Highlands Co.: Archbold Biol. Sta. 7.IV.1971 & 13-17.IV.1981(3, USNMNH) ; Archbold Biol. Sta. 5.IV.1998 (2, BYU) ; Archbold Biol. Sta. 13-17.IV.1981 & 4.IV.1984 & 12.IV.1986 (3, FIMU) ; Archbold Biol. Sta. Red Hill Area 31.III.2005 at black light (1, USNMNH) ; Archbold Biol. Sta. Lk. Placid 7.IV.1983 (1, FIMU) . Leon Co.: Tallahassee 3.IV.1982 at light (1, ERPC) ; Tallahassee 11.IV.1976 (1, ERPC) . Levy Co.: hwy 24 at Alachua Co. line 9.IV.1980 (1, ERPC) . Marion Co.: 2.5 mi SSE Micanopy 6-13.III.2001 (1, TAMU) ; Ocala Nat. For. Hopkins Prairie 29.IV.1988 (1, ERPC) ; East Silver Springs Shores Malauka Road nr. Meadow Lake 10.IV.1992 (2, ERPC) ; SR 200 Paddok Mall on Quercus virginiana 15.IV.2008 (1, BYU) . Polk Co.: Lk. Marion Crk. Rd. 25.III.1999 (1, USNMNH) . St. Johns Co.: St. Augustine 29°55.4’ N 81°17.9’ W 10.IV.2004 (2, BYU) . Wakulla Co.: Ochlockonee State Park 23.IV.1986 (1, FIMU) . GEORGIA, Johnson Co.: 1 mi E Kite 7.IV.1977 (1, ERPC) . MISSISSIPPI, Jackson Co.: Jackson County 25.III.2020 (1, GBIF) . TEXAS, Bastrop Co.: 7.3 mi S Rosanky 8.V.2005 (1, DSPC) ; Buescher St. Pk. 22.IV.1973 (1, TAMU) . Brazos Co.: College Sta. Riley Estate 30°35’18’’ N 96°15’12’’ W 17-19.IV.2006 & 13.IV.2007 (5, ERPC) ; College Station Lick Ck. Pk. 13.IV.1996 (2, ERPC) ; College Station 21.IV.1933 (2, TAMU) . Burleston Co.: 7 mi NW jct. Hwy 21 on FM 908 30.V.2004 (1, ERPC) . Tyler Co.: 4 mi E Spurger 24-25. III.1995 (2, TAMU) . Victoria Co.: 3 mi S Inez 6.V.1978 (1, FIMU) .

Distribution. U.S.A.

Diagnosis. The species is very similar in size, body outline and colour pattern to G. mokaya , but only in a single case the pronotal black spots are missing, while this condition is usual at least in some populations of G. mokaya . Additionally, the elytral spots are always rounded and do not seem to have the tendency to coalesce. The major differences, however, are shown by the different ventral profile of the aedeagal median lobe ( Figs 3o and 6o ) and the different shape of the spermathecal vasculum ( Figs 3i and 6i ).

Description of male. Habitus in Figs 6c, 6g . BL = 3.2–3.4 mm, BW = 1.9–2.1 mm, PL = 1.1–1.2 mm, PW = 1.6–1.9 mm. Interocular distance = 0.0–2.9 % of BL.

Head totally yellow, at times vertex and antennal insertions darkened. Labrum yellow as well. Head surface almost devoid of punctation and setosity. Mid-cranial suture shallow, but clearly detectable above and below the upper lobes of eyes. Upper lobes of eyes very close to each other but usually not really in contact, so that narrow interspace and mid-cranial suture are visible in between. Ocular lines strictly adhering to ocular rim, sometimes marked with hint of very fine punctures aligned along lower part of upper lobes. Ocular canthus large, angular, with surface not differentiated by remainder of frontoclypeus. Antennae ( Fig. 6h ) with first 5 antennomeres yellow, 3-5 bright, subcylindrical; 6-11 darker, dull, more flattened and more diffusedly setose.

Pronotum yellow with two rounded black spots on central part of disc, at sides of midline. Rarely such spots slightly obliquely elongated, or smaller, but never missing. Sometimes a hint of longitudinal brownish line near posterior margin, in front of scutellum. Pronotal shape elliptical, scarcely transverse, slightly flattened. Lateral margins narrow, visible from above only along posterior half, slightly angulate just behind middle, where maximum width occurs. Surface moderately shiny with usually strongly impressed punctation almost evenly distributed across whole pronotal surface. Sometimes punctures thinner on central part of disc. Posterolateral impressions weakly impressed but easily detectable.

Scutellum black, regularly rounded at apex or shortly truncated in almost straight line. Surface sparsely micropunctured.

Elytron yellow with three rounded black spots on disc, first one near basal margin between first and fifth rows of punctures, second one on humeral callus, third one just behind midline at about same distance from suture and lateral margin. Posterior part of lateral margin black as well. Elytral black pattern sometimes more or less reduced to almost totally missing, but at least brownish marking on humeral callus always present. Elytral outline lengthened, with sides almost straight and slightly convergent posteriorly. Lateral margins narrow, simultaneously visible along posterior half when seen from above. Elytral surface moderately shiny with strong, well-impressed punctation distinct up to posterior clivus, arranged in almost regular rows. Intervals flat. Postscutellar area slightly raised. Humeral callus prominent, impunctate. Epipleuron, impunctate, slightly rugulose with flat surface.

Pygidium yellow with rounded black spot at apex. Surface bright, covered with shallow punctures and short, semi-erect pale setae.

Ventral parts of thorax black with yellow hypomera and prosternal process. Abdominal ventrites black with large yellow margins. Hypomera, mesoepimera and mesoepisterna shiny, with few, well-impressed punctures, almost devoid of setosity. Remainder of ventral surface matt, covered with short, regularly distributed setae and fine, shallow punctures. Prosternal process large, with sides slightly salient, almost straight between anterior coxae; surface almost flat, shallowly punctured, covered with semi-erect setae. Legs totally yellow.

Median depression on fifth abdominal ventrite indistinct, hardly detectable. Ventrite posterior margin straight. Median lobe of aedeagus ( Fig. 6 m-o) dorsoventrally flattened, terminated by triangular apex with regularly convergent, straight sides. In lateral view apex slightly bent dorsally. Ventral surface weakly convex towards apex. Setose depressions barely delimited, with few short setae.

Female. Habitus in Fig. 6 a-b (NT), 6d-f. BL = 3.4–3.9 mm, BW = 2.1–2.3 mm, PL = 1.2–1.3 mm, PW = 1.8–2.0 mm. Interocular distance = 7.7–8.8 % of BL.

In females the eyes are smaller and more separated along midline, and mid-frontal suture clearly visible. The colour pattern is similar to the males one, but in a single studied specimen the pronotal black spots are totally missing.

The fifth abdominal ventrite in females has a quite large, rounded, and deep pit. The bottom of the pit is black, glabrous, matt, impunctate but covered by tiny wrinkles. The vasculum of the spermatheca ( Fig. 6i ) is subangular, hook-shaped, with proximal section twisted, slender and almost uniform in section. The ampulla is brief, with the duct insertion short and straight. The sperm gland insertion is rather long and curved. The duct is uniform in size, slender, straight. At the insertion of the ductus, the bursa copulatrix shows a couple of membranous coils.

Figures

Fig. 6 – Griburius equestris. a–b, habitus, dorsal and lateral view (NT, female); c, frontal view, male; d, frontal view, female; e–f, colour variation, females; g, posterior view, male; m–o, median lobe of aedeagus in ventral (m), dorsal (n) and lateral (o) view [0.6 mm]; h, antenna [0.9 mm]; i, spermatheca [0.5 mm]. Square brackets: length of scale segment.

Fig. 9 – Distribution maps. a, Griburius equestris; b, G. gamma.

Fig. 3 – Griburius mokaya sp. nov. a–b, habitus, dorsal and lateral view (HT, male); c, frontal view, male; d, frontal view, female; e–f, colour variation, female (e) and male (f); g, posterior view, male; m–o, median lobe of aedeagus in ventral (m), dorsal (n) and lateral (o) view [0.5 mm]; h, antenna [1.5 mm]; i, spermatheca [0.6 mm]. Square brackets: length of scale segment.