Diochus parvulus Kraatz, 1860

Caron, Edilson, Navarro, Bruna V. & Cajaiba, Reinaldo L., 2020, Diochus cleidecostae, a new species from the Brazilian Amazon and a discussion of the sexual dimorphism on sternum VIII (Coleoptera: Staphylinidae: Staphylininae: Diochini), Papéis Avulsos de Zoologia (Pap. Avulsos Zool., S. Paulo) 60 (31), pp. 1-6 : 3-5

Diochus parvulus Kraatz, 1860

( Figs. 5 , 10-14 )

Diochus parvulus Kraatz, 1860: 27 (original description, type locality: “ Bahia ”); Bernhauer & Schubert, 1914: 319 (catalogue, as valid species); Blackwelder, 1943: 456 (mention as synonym of D. nanus Erichson ); Blackwelder, 1944: 143 (catalogue, as synonym of D. nanus Erichson ); Herman, 2001: 2447 (catalogue, as synonym of D. nanus Erichson ); Irmler, 2017: 39 (re-description, as valid species).

Holotype (not seen) deposited in Senckenberg Deutsches Entomologisches Institut , Müncheberg, Germany ( SDEI) ( Irmler, 2017).

Material examined: “ Brasil, Pará, Uruará / Mata [Native vegetation], VI-2015, / Intermediário [collection information], / Pitfall banana / Reinaldo, Wully, Lucas, / Sidi, col.” [white label, printed in black] (1 ♂, dissected, DZUP). “ Brasil, Pará, Uruará / Pastagem [Pasture for extensive livestock], VI-2015, / Intermediário [collection information], / Serrapilheira [Forest litter] / Reinaldo, Wully, Idielson, / col.” [white label, printed in black] (1 ♀, dissect- ed, no head, DZUP).

Diagnosis and description: See Irmler (2017: 39-41).

Remarks: The specimens from Pará, identified as Diochus parvulus , have similar aedeagus (mainly parameres) and spermatheca as those illustrated by Irmler (2017) ( Figs. 10-14 ). However, similarly to Diochus santacatarinae , the male of D. parvulus has the sternum VIII with posterior margin emarginate at the middle, whereas the female has the sternum VIII with posterior margin broad curved and slightly acute at the middle.

The specimens of D. parvulus were collected using the winkler method in forest litter of pasture for extensive livestock and using pitfalls baited with banana in native vegetation ( Fig. 2 ).

Diochus parvulus was previously known from Venezuela, Ecuador, Paraguay, Argentina and Brazil (from the states of Amazonas, Mato Grosso, Rio de Janeiro and Santa Catarina). The species is recorded for the first time from the state of Pará.

Diochus cleidecostae Caron & Navarro sp. nov. ( Figs. 6 , 15-17 , 20-22 )

Type material: HOLOTYPE (♂, DZUP): “ Brasil, Pará , Uruará / Cap 5 [secondary vegetation with five years of

regeneration], VI-2015, / Intermediário [collection information], Serrapilheira [Forest litter] / Reinaldo, Wully, Sidi, col.” [white label, printed in black] ; “ HOLOTYPE / Diochus cleidecostae Caron & Navarro / det. E. Caron,2019” [red label, printed in black]. PARATYPES:the first label as the holotype; “ PARATYPE / Diochus cleidecostae Caron & Navarro / det. E. Caron, 2019” [yellow label, printed in black] (2 ♂, 2 ♀, DZUP and 1 ♂, 1 ♀, MZSP).“ Brasil, Pará, Uruará / Mata [native vegetation], IX-X-2015, / Verão [summer season], Pitfall-carne [fresh meat] / Reinaldo, Wully, Lucas, / Sidi, col.” [white label, printed in black] ; “ PARATYPE / Diochus cleidecostae Caron & Navarro / det. E. Caron, 2019” [yellow label, printed in black] (1 ♀, DZUP) .

Diagnosis: Within Diochus nanus-group, D. cleidecostae Caron & Navarro sp. nov. differs from D. apicipennis Cameron , D. nanus and D. perplexus Cameron by having an aedeagus with clearing trifurcate apex of parameres (parameres bifurcate at the apex in D. apicipennis , D. nanus and D. perplexus ), and differs from D. parvulus by having three apical long setae of parameres distributed on ventral and dorsal lobes, and without long setae on medial lobe (one of three apical long setae on medial lobe in D. parvulus ).

Description: Male: Maximum body length: 3.00 mm; maximum elytral width: 0.56 mm. Body light brown to

brown, elytra darker ( Fig. 6 ); appendices yellowish, antennae slightly darker than other appendices; antennomere 11 with apical half lighter than basal half. Head: Head longer than wide, length 0.40 mm, width 0.34 mm; eyes prominent, 0.11 mm long; temples twice as long as eyes; EL: HL = 0.28; temples parallel, PW: EW = 1.18; posterior angles rounded. Dorsal surface of head slightly microsculptured, vertex impunctate midline, convergent row of four punctures from anterior edge of eyes to middle of vertex, postocular area and at posterior marginal area more setiferous punctures. Antennae slightly longer than head; antennomere 1 nearly as long as 2-3 combined; 2 as long as 3; 3 one-fourth longer than 4; 4-10 wider than long, with same length, slightly increasing in width; 10 around twice wider than long; 11 nearly wid- er than 10 and length of 9-10 combined ( Fig. 20 ). Gular plate with sides divergent towards anterior margin. Thorax: Pronotum longer than wide, 0.50 mm long and 0.44 mm wide; anterior and posterior angles rounded; anterior third strongly convergent. Dorsal surface of pronotum glossy; adjacent to wide impunctate midline with row of three punctures; interstice between anterior pair twice as wide as interstices between posterior pairs; four additional punctures laterad; several setiferous punctures along lateral margin. Elytra wider than long, 0.44 mm long, 0.56 mm wide; sides divergent towards posterior margin; posterior margin slightly emarginate. Elytra glossy, setiferous punctures in irregular rows; first row of five punctures adjacent to suture line; two additional rows laterad; interstice between two rows on disc much closer than between row at suture and first row on disc.Hind wings developed.Tarsal formula 5-5-5; fore tarsomeres 1-4 strongly dilated; mid and hind tarsomeres 1-4 clearing decreasing in length; mid and hind tarsomeres 5 nearly the length of 3-4 combined. Abdomen: Abdominal segments III-VI with sides subparallel, VII-VIII clearing convergent to posterior margin; densely pubescent. Posterior margin of tergum VIII truncate at middle two-fourths. Posterior margin of sternum VIII emarginate at the middle. Tergum X separating tergum IX in two equal parts. Tergum IX with elongate ventral struts. Posterior margin of sternum IX emarginate at the middle. Posterior margin of tergum X rounded. Aedeagus twice as long as wide ( Figs. 21-22 ); seminal vesical of endophallus diagonal, 0.62 times as long as central lobe; basal inner duct shortly looped; complex of sclerotised apical forceps; central lobe with acute and crossed apical hooks. Parameres well-developed, each widened and forming large plate at the apex, trifurcate; three apical long setae, two on ventral lobe and one on dorsal lobe ( Figs. 15-16 ).

Female: Similar to male, except for posterior margin of sternum VIII broadly rounded; tergum IX without ventral struts; sternum IX consisting of pair of hemisternites; spermatheca small with capsule of subspherical shape; bursa copulatrix in lateral position to coiled approximately circular duct ( Fig. 17 ).

Biological notes: The specimens of D. cleidecostae sp. nov. were found in forest litter secondary vegetation (five years of regeneration) and native vegetation ( Figs. 1, 2 ).

Etymology: The specific name “cleidecostae” is formed from a personal name and treated as noun in the genitive case (ICZN, 1999, art. 31.1). The specific name honors the Brazilian coleopterologist Dr Cleide Costa, from MZSP and specialist of immature insects.

Key to males of the Neotropical species of Diochus belonging to the D. nanus -group (Adapted from Irmler, 2017, through the couplets 27 to 29)

Figures

Figures 4-6. Habitus (dorsal). (4) Diochus santacatarinae Irmler; (5) D. parvulus Kraatz; (6) D. cleidecostae Caron & Navarro sp. nov., paratype (female). Scale bars:1 mm.

Figures 7-17. Dissected parts,microscope photographs.(7-9) Diochus santacatarinae Irmler:(7) Paramere;(8) Apex of aedeagus;(9) Spermatheca;(10-14) D.parvulus Kraatz: (10) Paramere; (11) Spermatheca; (12) Apex of paramere, focusing on ventral lobe; (13) Apex of paramere, focusing on median lobe; (14) Apex of paramere, focusing on dorsal lobe. (15-17) D. cleidecostae Caron & Navarro sp. nov.: (15) Paramere (dashed line indicates lost seta); (16) Apex of paramere; (17) Spermatheca.Scale bars:0.06 mm.

Figures1-3. (1) Municipalityof Uruará,state of Pará,northern Brazil(PF,primary forest;SF-15,secondary forest with15 years of regeneration;SF-5,secondary forest with five years of regeneration;Ag = agriculture;Pa = pasture for extensive livestock). (2) Detail of primary forest. (3) Detail of agriculture (cocoa plantations,Theobroma cacao L.).

Figures 18-22. Dissected parts, drawings.(18-19) D. santacatarinae Irmler: (18) Sternite 8 of male, ventral; (19) Sternite 8 of female, ventral; (20- 22) D. cleidecostae Caron & Navarro sp. nov.: (20) antenna; (21) Aedeagus, dorsal;(22) Aedeagus,ventral.Scale bars:0.5mm.