Passalus (Passalus) lockerum Mattos and Mermudes, 2018

Mattos, Ingrid & Miras Mermudes, José Ricardo, 2018, A new species of Passalus (Passalus) from Atlantic Rainforest, with a key and checklist for the Brazilian Petrejus group (Coleoptera, Passalidae), Journal of Natural History 52 (37 - 38), pp. 2351-2367 : 2353-2362

publication ID	https://doi.org/ 10.1080/00222933.2018.1536813
publication LSID	lsid:zoobank.org:pub:A0A6251E-DFD0-4BB7-90EE-D7FA29AE8243
persistent identifier	https://treatment.plazi.org/id/76348783-FFE6-FFCC-DF6A-FE87ACF10370
treatment provided by	Felipe
scientific name	Passalus (Passalus) lockerum Mattos and Mermudes
status	sp. nov.

Treatment

Passalus (Passalus) lockerum Mattos and Mermudes View in CoL , sp. nov.

( Figures 1–6 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 )

Type material

HOLOTYPE ( Figures 1–6 View Figure 1 View Figure 2 View Figure 3 View Figure 4 View Figure 5 View Figure 6 ) male from BRAZIL: Rio de Janeiro, Cachoeiras de Macacu ( RPPN, Reserva Ecológica de Guapiaçu , REGUA, cruzamento das trilhas Marrom e São José), 21 March 2015, Mermudes et al. col. ( DZRJ) . PARATYPES, with same data of Holotype: 1

male, 4 female ( CEIOC) and 4 females ( DZRJ); 1 female, same locality (trilha da Pedra D’ água), 22 May 2010, Mattos col . ( DZRJ).

Etymology

The name is in honour of the Locke family, especially the conservationists Nicholas Locke and Raquel Locke, for their memorable enthusiasm and contributions to Atlantic Rainforest conservation.

Diagnosis

Frontal area ( Figures 2 View Figure 2 , 3 View Figure 3 (a)) fine and sparsely punctate, interstices shiny; anterior region with distinct coarse, rounded and shallow punctures, contiguous or not. Secondary median frontal tubercles merged, vestigial to small and subcontiguous at base. Aedeagus with parameres widely truncated at apex (dorsal view, Figure 6 View Figure 6 (a)), longitudinally subdivided, anterior margin feebly notched.

Description

Length 22–25 mm. Body slightly convex. Head ( Figures 2 View Figure 2 , 3 View Figure 3 , –4(a)) with anterior margin straight. Labrum with coarse and shallow setiferous punctures, interstices with microsculpture; anterior margin slightly concave and strongly setose. Frontal area ( Figures 2 View Figure 2 , 3 View Figure 3 ) fine and sparsely punctate, interstices shiny; anterior region with distinct coarse, rounded and shallow punctures, contiguous or not; more than twice as wide as long; lacking posterior elevation. Anterior and posterior frontal ridges feebly elevated, ending before reaching medial frontal tubercles. Secondary median frontal tubercles merged, vestigial to small and subcontiguous at base ( Figure 2 View Figure 2 (a)). Inner tubercles evident, smaller than lateral medial tubercles, these prominent. Central tubercle ( Figures 2 View Figure 2 (b), 3(a)) elongate and pyriform, with apex free and straight, strongly projected forward; base slightly wider, uniformly swollen. Lateral posterior tubercles feebly marked. Frontal fossae sparsely corrugated, deep; bridge robust and smooth. Postfrontal groove with large concave area, corrugated. Mentum ( Figure 4 View Figure 4 (a)), in median area with rare and isolated punctures, or completely smooth; at each side with lateral scars ample, deep and opaque; each lobe with coarse setiferous punctures. Antennae: apical club with three antennomeres, subequal in length; IX and VIII with similar width; VII–VI both projected, VI more widely projected.

Pronotum ( Figures 1 View Figure 1 (a), 1(b), 2(a)) with fine and moderately sparse punctures; anterior margin straight at middle, distinctly curved before anterior angles; anterior and lateral marginal groove narrow and shallow, with a row of coarse punctures; anterior groove extends on 2/3 of anterior margin, sinuous. Sides of pronotum with irregular punctures, more dense on posterior half; distinct scars, marked by punctures, more evident near the scars. Prosternal process rhomboidal, opaque; apical third narrower, truncated and brilliant.

Elytra with humeri smooth and brilliant, inferiorly with rare, sparse and fine setae; first four striae with small punctures, these smaller than wide interstriae; from the fifth lateral striae with coarser punctures, bigger than interstriae. Mesosternum ( Figures 4 View Figure 4 (b), 5(a)), scars undelimited, elongate, shallow and opaque, slightly wider posteriorly. Metasternum ( Figure 5 View Figure 5 (a)) with lateral fossae very narrow and opaque; anterior lateral area with a group of confluent punctures, restricted at anterior angles; median lateral area smooth and shiny; disc of metasternum weakly delimited only by group of punctures contiguous, moderately coarser at the posterolateral area. Mesotibiae dorsally with sparse pubescence and laterally with two distinct medial spines. Metatibiae with pubescence sparse and with one diminute medial spine.

Aedeagus ( Figures 6 View Figure 6 (a–c)): subglobose, 1,5× longer than wide. Phallus (ventral view, Figure 6 View Figure 6 (c)) slightly elongate, distinctly sclerotized at ventral and lateral regions, finely punctate. Parameres and phallobase not fused, with evident suture (ventral view). Phallobase narrower than parameres (lateral view, Figure 6 View Figure 6 (b)), notched ventrally. Parameres widely truncated at apex (dorsal view, Figure 6 View Figure 6 (a)), longitudinally subdivided, anterior margin feebly notched. Phallobase almost as long as the parameres.

Dimensions (mm)

Total length = 22–25 mm (from anterior margin of labrum to apex of elytra); elytral length = 11–11.8 (on median line); pronotal length = 4–4.6 (on median line); pronotal width = 5–5.6; humeral width = 6–6.4.

Distribution

Passalus (Passalus) lockerum sp. nov. is found in lowland areas of Atlantic Rainforest at the Reserva Ecológica de Guapiaçu.

Remarks

The differences around length of frontal area are remarkable between the several Brazilian species of Section Petrejus , being shorter than wide in Passalus (Passalus) aculeatus and P. (P.) plicatus , twice as wide as long in P. (P.) nasutus and P. (P.) procerus and at least more than twice wider than long in P. (P.) armatus , P. (P.) coordinatus , P. (P.) fractus , P. (P.) nasutus and P. (P.) sicatus .

Still, some Brazilian Petrejus species differ from each other by the general pattern of mesosternum and metasternum. The integument of mesosternum is generally not punctate and smooth, but pubescent among the follow species: P. (P.) aduncus , P. (P.) coordinatus , P. (P.) fractus and P. (P.) nasutus . The other species, P. (P.) aculeatus , P. (P.) armatus , P. (P.) mucronatus , P. (P.) plicatus , P. (P.) procerus , P. (P.) sicatus , including Passalus (Passalus) lockerum sp. nov., show the mesosternum glabrous. Within this group, P. (P.) aculeatus , P. (P.) plicatus , P. (P.) procerus , and P. (P.) sicatus have pubescence on the metasternum. Finally, Passalus (Passalus) lockerum sp. nov. has remarkable differences on central tubercle morphology, which is elongate and pyriform 2(a), 3(a), 3(b), a distinct pattern in South American species of Petrejus .

Passalus (Passalus) lockerum sp. nov. is similar to Passalus (P.) coordinatus by median frontal secondary tubercles being vestigial, but the former easily differs by having the inner tubercles in the midline of the frontal area. Also, the frontal area is distinctly punctate, with coarse punctures, the mesosternal scars are elongate, shallow and opaque, and the mesotibiae have two spines. In Passalus (P.) coordinatus the inner tubercles are near the medial frontal tubercle, with frontal area smooth. It also differs from Passalus (P.) fractus Kuwert, 1891 , which has the central tubercle with groove in the posterior half and the scars of the mesosternum indistinct.

Thus, Passalus (Passalus) lockerum sp. nov. ( Figure 1 View Figure 1 ) is similar to the other Brazilian species of Section Petrejus , by the central tubercle swollen, with apex free, and projected forward. However, the new species is easily distinguished from other species by presence of: (1) secondary median frontal tubercles small and contiguous at the base ( Figure 2 View Figure 2 (a)); (2) central tubercle pyriform and swollen at base ( Figure 2 View Figure 2 (a)); (3) scar of mesosternum ( Figure 4 View Figure 4 (b)) undelimited and opaque, elongated, slightly wider posteriorly; (4) aedeagus ( Figure 6 View Figure 6 ): subglobose, 1,5× longer than wide; (5) parameres and phallobase not fused, with evident suture (ventral view); (6) phallobase narrower than parameres (lateral view, Figure 6 View Figure 6 (b), notched ventrally; (7) parameres widely truncated at apex (dorsal view, Figure 6 View Figure 6 (a)), longitudinally subdivided, anterior margin feebly notched.

For details and comparison between Passalus (Passalus) lockerum sp. nov. and the other species, see the key below.

Key to the Brazilian species of Petrejus View in CoL group

1 Apex of central tubercle concave in dorsal view, and broadly free at apex. Length 40–51 mm .................................................................................................................... P. armatus Perty View in CoL

1 ʹ Central tubercle with other shape. Length <33 mm ................................................................ 2

2 Secondary mediofrontal tubercles well developed, sometimes fused at the base ...... 3

2 ʹ Secondary mediofrontal tubercles lacking or vestigial. .......................................................... 6

3 Central tubercle wider in the middle, anterior and posterior region attenuated......... 4

3 ʹ Central tubercle evenly wide, more or less flatly dorsally, and sometimes grooved...... ...................................................................................................................................... P. procerus Hincks View in CoL

4 Meso- and metepisternum glabrous................................................................................................. 5

4 ʹ Meso- and metepisternum pubescent........................................................ P. aduncus Ericson View in CoL

5 Anterior angles of pronotum obtuse or rounded. ............................ P. sicatus Burmeister View in CoL

5 ʹ Anterior angles of pronotum straight or acute............ ........... P. mucronatus Burmeister View in CoL

6 Humerus without tuft of hairs, at most part only with dense and short pubescence. 7 6 ʹ Humerus with distinct tuft of hairs, or at most part with long and abundant hairs. 10

7 Frontal ridges starting almost at the end of the central tubercle........................................... ........................................................................................................................... P. coordinatus (Kuwert) View in CoL

7 ʹ Frontal ridges starting far from the central tubercle ............................................................... 8

8 Central tubercle grooved...................................................................................................................... 9

8 ʹ Central tubercle not grooved............................................................................................................ 10

9 Central tubercle, at least in the proximal half, with fine dorsal longitudinal groove...... ...................................................................................................................................... P. fractus (Kuwert) View in CoL

9 ʹ Central tubercle transversely grooved only in the base................ P. plicatus Percheron View in CoL

10 Central tubercle with apex free, not projected............................... P. nasutus Percheron View in CoL

10 ʹ Central tubercle with apex distinctly projected. .................................................................... 11

11 Central tubercle apex with obtuse angle, and projected forward and upward.............. .......................................................................................................................... P. aculeatus Percheron View in CoL

11 ʹ Central tubercle elongate and pyriform, with apex free and straight, strongly projected forward; base slightly wider, uniformly swollen.............................................................. ............................................................................... P. lockerum Mattos and Mermudes View in CoL , sp. nov.