Isorhipis bicolor Otto, 2024

Otto, Robert L., 2024, Three additions to the false click beetle (Coleoptera: Elateroidea: Eucnemidae) fauna in the Nearctic region, Insecta Mundi 2024 (47), pp. 1-14 : 4-6

Isorhipis bicolor Otto , new species

Fig. 1–4

Diagnosis. Infuscate reddish black femur with reddish tibiae and tarsi along with the coloration of the elytra will distinguish the new species from I. obiqua and I. nubila . Well-developed pygidial keel on tergite VII will also distinguish I. bicolor from I. ruficornis . Well-developed, punctate elytral striae will further distinguish the new species from I. occidentalis .

Type material. Male holotype: “ USA: Florida, Nassau Co. / Yulee, Agricultural Interdiction / Station, 16b (I95), 30.72689 / −81.66414, Lindgren funnel, EtOH / lure, 25.iv.14, Traya” // “ HOLOTYPE: / Isorhipis / bicolor ♂ / Otto / Det. R.L. Otto / 2023” (red printed label). Female allotype: “ Florida: Alachua Co. / San Felasco H.P.S.P. / 29.7172, −82.4594 / March 7–20, 2022 / Lindgren funnel trap / Kyle E. Schnepp” // “ ALLOTYPE: / Isorhipis / bicolor ♀ / Otto / Det. R.L. Otto / 2023” (yellow printed label). Holotype and allotype are deposited in FSCA.

Paratypes. 5 ♀♀: UNITED STATES of AMERICA: FLORIDA: Alachua County: 1 ♀, “ Florida: Alachua Co. / San Felasco H.P.S.P. / 29.7172, −82.4594 / March 7–20, 2022 / V-flight intercept trap / Kyle E. Schnepp ” // “ PARATYPE: / Isorhipis / bicolor ♀ / Otto / Det. R.L. Otto / 2023” (yellow printed label) (KESC) ; 2 ♀♀, “ Florida: Alachua Co. / San Felasco H.P.S.P. / 29.7172, −82.4594 / April 3–10, 2022 / V-flight intercept trap / Kyle E. Schnepp ” // “ PARATYPE: / Isorhipis / bicolor ♀ / Otto / Det. R.L. Otto / 2023” (yellow printed label) (1, KESC; 1, CMNH) ; 1 ♀, “ Florida: Alachua Co. / San Felasco H.P.S.P. / 29.7172, −82.4594 / April 18–30, 2022 / Lindgren funnel trap / Kyle E. Schnepp ” // “ PARATYPE: / Isorhipis / bicolor ♀ / Otto / Det. R.L. Otto / 2023” (yellow printed label) (KESC) ; 1 ♀, “ Florida: Alachua Co. / San Felasco H.P.S.P. / 29.7172, −82.4594 / April 21–30, 2022 / V-flight intercept trap / Kyle E. Schnepp ” // “ PARATYPE: / Isorhipis / bicolor ♀ / Otto / Det. R.L. Otto / 2023” [yellow printed label] ( GERP) .

Description. Male holotype: Length, 7.0 mm. Width, 1.7 mm. Body oblong and elongate; uniformly black; basal 2/3 of the elytra infuscate reddish orange, apical 1/3 of elytra black; basal margin of the elytral humeri, scutellar shield and venter black; antennae infuscate reddish brown; femur infuscate red and black; tibiae and tarsi reddish; head, pronotum and elytra clothed with short, recumbent yellowish setae ( Fig. 1 ). Head: Surface densely punctate, dullish, subspherical; frons convex, without median carina or fovea above frontoclypeal region; apical margin of frontoclypeal region rounded, less than 2 times wider than base; carinae present along the lateral edges of the frontoclypeal region; mandibles stout, bidentate, densely punctate. Antenna: Flabellate from flagellomeres II–VIII, attaining about 1/4 the length of the body, never beyond pronotal hind angles; flagellomere I longer than II; flagellomeres II–IV each sub-equal, transverse; flagellomeres V–VI each sub-equal, quadrate; flagellomeres VII–VIII each sub-equal, longer than wide; rami elongate, arising near base of flagellomere II, arising near apices of flagellomeres III–VIII; flagellomere IX simple, ramous. Pronotum: Surface dullish, densely punctate; longer than wide, with short, divergent hind angles; lateral sides arcuate and slightly narrowing towards craniad; disc convex with pair of shallow lineal fovea and median depression at apical 1/2; short, basal carina present extending near center; base sinuous. Scutellar Shield: Slightly longer than wide, sub-triangular, setose, punctate and distally rounded. Elytra: Distinctly striate; striae punctate; interstices elevated; surface shiny, basal 3/4 closely punctate, transversely rugose at apical 1/4; excretory grooves/punctures absent at elytral apices. Abdomen: Tergite VII exposed beyond elytra; pygidium strongly keeled. Legs: First tarsomere as long as the combined lengths of the remaining four on mesothoracic and metathoracic tarsi; tibiae rounded in cross section; metathoracic tarsomeres I–III simple; metathoracic tarsomere IV very short, slightly excavated; metathoracic tarsomere V elongate; pretarsal claws simple. Venter ( Fig. 2 ): Closely punctate, with short, recumbent yellowish setae; abdomen transversely rugose; hypomeron simple, without antennal grooves; metathoracic episterna caudally wide; elytral epipleura punctate; metathoracic coxal plates medially 3.0–6.0 times wider than laterally.

Female allotype ( Fig. 3–4 ): Length, 7.0 mm. Width, 1.7 mm. Antennae dark reddish brown, serriform, about 1/4 the length of the body; flagellomere I longer than wide, longer than II; flagellomeres II–VIII transverse, each subsequent segment being more wider than long than the previous; flagellomere IX asymmetrical, slightly longer than VIII. Basal 1/2 of elytra dark reddish, apical 1/2 of elytra black. Prothoracic legs uniformly reddish brown. Mesothoracic and metathoracic femur bicolored black and infuscate reddish with tibiae and tarsi reddish.

Variations. Five female paratypes were examined. These five paratypes measured 4.5–7.0 mm long and 1.2–1.7 mm wide. Four out of the five female paratypes are shorter and narrower than both the holotype and allotype. One female paratype is as long as and as wide as the holotype. Reddish orange coloration on the elytra is more reduced in the females compared to the male holotype, that being about the basal 1/2 of the elytra compared to the basal 2/3 observed in the holotype. None of the female paratypes have any pronotal depressions as observed in the male holotype. Antennae and legs in all of the female paratypes are darker compared against the holotype.

Distribution. This new eucnemid species is known from a couple of localities in the state of Florida, U.S.A.

Biology. One specimen was taken from a Lindgren funnel trap baited with EtOH in Nassau County, Florida. Two specimens were taken from Lindgren funnel traps and four specimens were taken from a V-flight intercept trap in Alachua County, Florida. Larvae and pupae are unknown.

Etymology. The specific epithet is derived from the presence of its bicolored tibiae as well as its dark reddishorange and black elytra.

Subfamily Eucneminae Eschscholtz, 1829

Diagnosis. Mandibles slender or stout, with or without ventral tooth; antennal flagellomeres VIII–IX increasingly serrate apically, tubular, sexually dimorphic; prothoracic tibiae with zero or one apical spur; lateral surfaces of mesothoracic and metathoracic tibiae flattened with sharp angles between lateral and caudal surfaces; male prothoracic tarsomere I with or without sex combs; tarsomere IV mostly simple; hypomeron with basally closed lateral antennal grooves; male aedeagus flattened; median lobe free, without dorsal basal struts; female eighth sternite partly sclerotized; bursa either bifurcate, divided or undivided; spermatheca sclerotized, divided ( Muona 1993, 2000, 2011; Otto 2016).

Tribe Dyscharachthini Muona, 1993

Diagnosis. Form cuneiform to cylindrical; frons usually with median keel; tarsomere IV excavate-emarginate simple; male prothoracic tarsomere I without sex combs; tarsomeres without ventral lobes; antennal flagellomeres I–IX flattened, serrate; hypomeron without hairy excretory organs along antennal grooves; mesothoracic sternum with tarsal grooves; basal piece dorsally closed; median lobe free, with entire apex, without dorsal basal struts; fused basal portion of lateral lobes dorsally attached to basal piece; lateral lobes with basally placed tooth, transversely divided dorsally, apices turned dorsocaudad; bursa simple, divided; spermatheca sclerotized, divided and globular.

Figures

Figures 1–4. Isorhipis bicolor new species. 1) Male holotype, dorsal habitus. 2) Male holotype, ventral habitus. 3) Female allotype, dorsal habitus. 4) Female allotype, ventral habitus. (Scale: 1–4 = 1.0 mm)