Mesomerodon barclayi Seidel, Jameson, & Stone

Seidel, Matthias, Jameson, Mary L. & Stone, Rachel L., 2017, A new cryptic species and review of the east-Andean leaf chafer genus Mesomerodon Ohaus, 1905 (Coleoptera, Scarabaeidae, Rutelinae), ZooKeys 671, pp. 61-85 : 66-69

Mesomerodon barclayi Seidel, Jameson, & Stone sp. n. Figs 1-3, 8, 15, 18, 22, 25

Type material.

Holotype male and 19 paratypes (10 males, 9 females). Holotype male at ZMHB with label data: a) "Rutelide, Pacayacu, 23.8.37" (handwritten), b) " Mesomerodon spinipenne Ohs., MNHUB Berlin" (typeset), c) male genitalia card mounted, d) our red holotype label. Paratype female at MSPC with label data: a) "Ecuador, Pacayacu, 3.X.37, Dr. Schultze - Rhonhof S.G." (typeset and handwritten), b) "Pacayacu 3.10.37" (handwritten), c) "loan from Zool.Mus. Berlin" (typeset), d) " Mesomerodon spinipenne Ohs., MNHUB Berlin" (typeset), e) our yellow paratype label. Paratype male at ZMHB with label data: a) "O.ECUADOR, Sarayacu Feyer" (typeset), b) " Mesomerodon spinipenne , Cotype ♂ Ohs." (handwritten on red label), c) "kein typus" (handwritten), d) male genitalia card mounted e) our yellow paratype label. Paratype female at ZMHB with label data: a) "O.ECUADOR, Sarayacu Feyer" (typeset), b) " Mesomerodon spinipenne , Cotype ♀ Ohs." (handwritten on red label), c) "kein Typus" (handwritten), d) our yellow paratype label. Paratype male at ZMHB with label data: a) "O.ECUADOR, Sarayacu Feyer" (typeset), b) “88882” (typeset), c) “♂” (typeset on black bordered label), d) " Mesomerodon spinipenne Ohs., MNHUB Berlin" (typeset), e) male genitalia card mounted, f) our yellow paratype label. Paratype female at ZMHB with label data: a) "Rutelide u. Cyclocephala, Pacayacu 24.9.37" (handwritten), b) " Mesomerodon spinipenne Ohs., MNHUB Berlin" (typeset), c) our yellow paratype label. Paratype female at ZMHB with label data: a) "O. Ecuador, Puyo, A. Schulze" (typeset), b) "Ohaus determ., Mesomerodon spinipenne ♀ Ohs." (typeset and handwritten), c) our yellow paratype label. Paratype female at ZMHB with label data: a) "O. Ecuador, Puyo, A. Schulze" (typeset), b) " Mesomerodon spinipenne Ohs." (handwritten), c) “♀” (typeset), d) our yellow paratype label. Paratype male at CCECL with label data: a) ECUADOR (Orellana), Payamino Research Station, 0°29'967"S, 77°17'083"W, 300m Tropical Rainforest, At M.V. light at night, 30. vii– 12 viii.2007" (typeset), b) male genitalia card mounted, c) our yellow paratype label. Paratype male at MSPC with label data: a) ECUADOR (Orellana), Payamino Research Station, 0°29'967"S, 77°17'083"W, 300m Tropical Rainforest, At M.V. light at night, 30.vii -12 viii.2007" (typeset), b) "coll. CPDT Gillett, BMNH(E) 2007-65" (typeset), c) "DNA extract No: Meso1, deposited at MSPC" (handwritten), d) male genitalia card mounted, e) "Matthias Seidel Collection 2016", f) our yellow paratype label. Paratypes (2 males) at BMNH with label data: a) ECUADOR (Orellana), Payamino Research Station, 0°29'967"S, 77°17'083"W, 300m Tropical Rainforest, At M.V. light at night, 30.vii -12 viii.2007" (typeset), b) "coll. CPDT Gillett, BMNH(E) 2007-65" (typeset), c) "DNA extract No: Meso2, deposited at MSPC; no PCR amplification" (handwritten), d) male genitalia card mounted, e) our yellow paratype label. Paratype male at SLCC with label data: a) "PARAGUAY: Alto Parana, 1.XI.1990" (typeset), b) "Collection S. Le Tirant" (typeset), c) "supposedly mislabeled locality, des. Seidel 2016" (typeset), d) "MESOMERODON SPINIPENNE OHAUS, det. M.E. Jameson 2003" (typeset and handwritten), d) male genitalia card mounted, e) our yellow paratype label. Paratype male at IRSNB with label data: a) "ECUADOR (Orellana), Payamino Territory, 300m Tropical Rainforest, July 2007" (typeset), b) "DNA extract: Rut105, det. M.Seidel 2016" (typeset and handwritten), c) male genitalia card mounted, d) our yellow paratype label. Paratype male at ZSM with label data: a) "O.Ecuador, Puyo, A. Schulze, 6.V.35" (typeset and handwritten), b) " Mesomerodon spinipenne Ohs." (handwritten), c) "Staatssammlung München, 1975, Erwerb Coll. Machatschke", d) male genitalia card mounted, e) our yellow paratype label. Paratype female at NMPC with label data: a) "O.Ecuador, Puyo, A. Schulze, 6.V.35" (typeset and handwritten), b) "Ohaus determ., Mesomerodon spinipenne ♀ Ohs." (typeset and handwritten), c) "Staatssammlung München, 1975, Erwerb Coll. Machatschke", d) our yellow paratype label. Paratype female at ZSM with label data: a) "O.Ecuador, Sarayacu Feyer" (typeset), b) "Paratypus, Mesomerodon spinipenne Cotype ♀ Ohs." (typeset and handwritten), c) "Staatssammlung München, 1975, Erwerb Coll. Machatschke", d) "NOT a type specimen of Mesomerodon spinipenne , Ohaus, 1905, des. Seidel 2016" (typeset), e) our yellow paratype label. Paratype male at FMNH with label data: a) "ECUADOR: Pastaza; 300m confluence R. Macuma & R. Morona VII:17:1971, leg. B. Malkin" (typeset), b) "at light" (typeset), c) "on sand river bank" (typeset), d) male genitalia card mounted, f) our yellow paratype label. Paratype female at FMNH with label data: a) "ECUADOR: Pastaza; 300m confluence R. Macuma & R. Morona VII:17:1971, leg. B. Malkin" (typeset), b) "at light" (typeset), c) "on sand river bank" (typeset), d) " Mesomerodon spp??? DET. A.R.Hardy 1980" (typeset and handwritten), f) our yellow paratype label. Paratype female at FMNH with label data: a) "ECUADOR: Pastaza; 300m confluence R. Macuma & R. Morona VII:17:1971, leg. B. Malkin" (typeset), b) our yellow paratype label.

Description

(based on 11 males and 9 females). The holotype does not differ significantly from the generic description and suffices for the description of this cryptic species (see “Remarks”). Descriptive details specific to the holotype specimen are indicated. Length from apex of clypeus to apex of pygidium 18-22 mm (♂) (holotype: 19 mm) and 22-25 mm (♀); width at mid-elytra 11-12 mm (♂) (holotype: 11 mm) and 12-15 mm (♀). Color: Cream colored (holotype), tan, or ochre; ventral surface castaneous with weak metallic green reflections. Form: Elytral apices with one short spine (holotype) or swelling (females). Legs: Protarsomere 2 of male ventrally lacking well-defined striae at ventral apex (Fig. 25). Male genitalia (Fig. 22 a–c): Parameres with elongate, narrow projection (=stem) and with longitudinal, impressed fissure (Fig. 22a); stem gradually and weakly broadened toward apex, subapex lacking paired, spinose projections; ventral sclerite of phallobase with surface concave, apex quadrate (Fig. 22c); lateral view diagnostic (Fig. 22b).

Diagnosis.

Males of Mesomerodon barclayi sp. n. are differentiated from other Mesomerodon species by the following combination of characters: Protarsomere 2 ventrally lacking a striated region at the ventral apex (striated in M. spinipenne ; apical region lacking striae in M. gilletti [Figs 25-27]) and form of the male genitalia (Fig. 22 versus Fig. 24 in M. spinipenne and Fig. 23 in M. gilletti ). Females can only be confidently determined when associated to male specimens from the same collecting event.

Etymology.

It is our honor to dedicate this species to Max Barclay (Curator, Coleoptera , Department of Entomology), who invited the first and second authors to the 1st Scarab Symposium at the BMNH in 2014 where cooperation on this work was initiated. Max Barclay has led the way in making biodiversity science more accessible to scientists and citizens alike.

Distribution

(Fig. 18). Known from western (lowland) Amazonia areas in Ecuador and occurring in apparent sympatry with M. gilletti . Ohaus (1934, 1952) recorded M. spinipenne from Sarayacu, Ecuador. We recovered these specimens in ZMHB and ZSM and identified them as belonging to M. barclayi sp. n.

Locality data

(Suppl. material 1). 20 specimens from 9 collections.

ECUADOR: Morona-Santiago, Orellana, Pastaza

Temporal data.

Based on label data, this species is known to be active in the months of February, August, and November.

Natural history.

Based on label data, adult M. barclayi sp. n. is usually collected at light, thus suggesting activity and feeding at night. Individuals probably occur throughout the year. Immature stages are unknown. Specimens have been recorded at an elevation of 300 m.

Remarks.

As with other cryptic species, the overall body form of M. barclayi sp. n. is similar to other species in the genus. The form of the male genitalia (Fig. 22 versus Figs 23-24) however, is sufficient for identification of M. barclayi sp. n. When developing our species hypotheses, we examined this morphotype in terms of phenotypic, elevational, and seasonal variation within M. spinipenne or M. gilletti , but the consistency in the form of the male genitalia led us to conclude that it is a justified species. Apparent sympatry (in location and phenology) with M. gilletti also led us to carefully examine this species pair. Again, we found that consistency in the male genitalia form was sufficient for diagnosis of both species. Females of M. barclayi sp. n. cannot be identified unless associated with males from the same collecting event.