Description of a new species of Trogoderma Dejean, 1821 from Norfolk Island (Coleoptera: Dermestidae: Megatominae)

Abstract

Trogoderma norfolkiana sp. nov. from Norfolk Island is described, illustrated and compared with related species; a differential diagnosis is also provided.

http://zoobank.org/urn:lsid:zoobank.org:pub:519C91E0-774C-4AA2-9870-2F6C24B32B7C

Keywords:

• Dermestidae
• new species
• Norfolk Island
• taxonomy
• Trogoderma

Introduction

The genus Trogoderma Dejean, 1821 is one of the 62 genera established in the skin beetle family (Dermestidae). It has a world-wide distribution and currently includes more than 146 species (Háva 2013, 2014a). Some of the species such as Trogoderma cavum Beal, 1982, Trogoderma granarium Everts, 1898, Trogoderma glabrum (Herbst, 1783), Trogoderma inclusum LeConte, 1854 and Trogoderma halsteadi Veer and Rao, 1994 have been recognised as pests of stored goods (Hinton 1945; Burges 1959; Kantack & Staples 1969; Mroczkowski 1975; Beal 1991; Lawrence & Ślipiński 2010; Kadej 2012). This paper provides a detailed morphological description of mature Trogoderma norfolkiana sp. nov. The newly described species has been discovered on Norfolk Island, which is located between Australia, New Zealand and New Caledonia. Most of the known Trogoderma (66 species) from these countries were described in the nineteenth century. Only three species—Trogoderma millei Háva, 2013, Trogoderma caledonica Háva, 2014b and Trogoderma lescheni Háva, 2014b—have been discovered recently.

Material and methods

Morphological structures (genitalia, antenna, pygidium) were boiled for 3–10 minutes in 10% KOH, and placed in distilled water for c.1 hour to clean and soften the cuticle. The structures, such as: genitalia, antenna, pygidium were placed on glycerine mounts. These morphological structures were examined with a Nikon Eclipse E 600 phase-contrast microscope and a Nikon SMZ-800 binocular microscope. Photographs were taken with a Canon 500D attached to a Nikon Eclipse 80i and a Nikon D5100 camera attached to a Nikon SMZ-800. Image stacks were processed using Combine ZM (Hadley 2010).

The terminology used in this paper follows Beal (1982), Háva and Kadej (2006) and Háva (2014a).

The following abbreviations denote the depositories for the specimens of the new species:

DIBEC: Department of Invertebrate Biology, Evolution and Conservation, Institute of Environmental Biology, Faculty of Biological Science, University of Wrocław, Wrocław, Poland.

JHAC: Private Entomological Laboratory and Collection, Jiří Háva, Prague, Czech Republic.

NZAC: New Zealand Arthropod Collection, Auckland, New Zealand.

The following abbreviations were used in this study:

EL: length of elytron

EW: maximum width of elytron

HT: holotype

PL: median pronotal length

PT: paratype

PW: maximum width of pronotum

TL: length from anterior margin of pronotum to apex of elytron.

The type specimens possess the following red labels: ‘HOLOTYPE [or PARATYPE] Trogoderma norfolkiana sp. n. J. Háva & M. Kadej det. 2015’.

Systematics

Family Dermestidae Latreille, 1807

Subfamily Megatominae Leach, 1815

Tribe Megatomini Ganglbauer, 1904

Genus Trogoderma Dejean, 1821

Trogoderma norfolkiana sp. nov. (Figs 1–2)

Type locality

Norfolk Island.

Types

Holotype (female). Norfolk I. [= Nepean I.], Pine Val. 350, 1.xi.67, G. Kuschel lgt., beating [abdomen, genitalia and left antenna dissected] (NZAC). Paratypes (9 ♀♀): Norfolk I. [= Nepean I.], Anson Bay, 4.xi.1967, G. Kuschel lgt., ex Lagunaria patersonii (6 NZAC, 2 JHAC, 1 DIBEC); (2 ♀): Norfolk I. [= Nepean I.], Middle Gate, 3.xi.1967, G. Kuschel lgt., beating mixed bush (NZAC). [One specimen of paratypes without left elytra; second one in two parts – head with pronotum + rest of the body].

Diagnosis

Trogoderma norfolkiana sp. nov. can be distinguished from the New Caledonian species by the characters mentioned in the following key:

1. Dorsal integument of elytra unicolorous brown………………………………………………… 2

2. – Dorsal integument of elytra bicolorous.… …………………………………………… 4

3. Setation unicolorous, integument dark brown, form of body parallel and elongate ………… ………………………………………………..T. caledonica Háva, 2014b

4. – Setation bicolorous ………………………… ………………………………………….. 3

5. Elytral setation brown, split by irregular fasciae of yellow setation, which extends from anterior margin under humeral calli along suture to elytral apices (compare with Háva, 2013 ……….T. millei Háva, 2013

6. – Elytra covered mainly with brown setation; fasciae of white setation present around humeral calli, under humeral calli at half length of elytra and in two-thirds of length of elytra above elytral apices (Fig. 1A–B).T. norfolkiana sp. nov.

7. Body parallel, pubescence on elytra bicolorous; elytral integument brown with two broad yellow transverse bands (in some specimens bands can be connected and then create one large yellow macula); antennal club brown ………………… T. vulneratum Fauvel, 1903

8. – Body oblong-ovate, pubescence on elytra unicolorous ……………………….……… 5

9. Integument of elytron black or dark-brown with large apical red spot; antennal club black ……………………………………………… ……………….….. T. asperatum Fauvel, 1903

10. –Each elytron dark-brown with small humeral red spot; antennal club brown ……………… ……………………………………………… …. T. lescheni Háva, 2014

Figure 1 Trogoderma norfolkiana sp. nov. Holotype: A, habitus, dorsal; B, habitus, ventral. Paratype: C, habitus, dorsal; D, habitus, ventral.

Of the nine Trogoderma species (including cosmopolitan) recorded from New Zealand, T. norfolkiana sp. nov. closely resembles Trogoderma granulatum Broun, 1886 and Trogoderma maestum Broun, 1880, but can be distinguished from these species by the following characters: in T. norfolkiana sp. nov. elytra with white, narrow transverse fasciae, not reaching elytral sutures; in T. granulatum Broun, 1886 elytra with white, broad transverse fasciae, reaching elytral sutures; whereas in T. maestum Broun, 1880 elytra with numerous white small, circular spots.

The newly described species is also similar to Trogoderma signatum Sharp, 1877 (New Zealand), but differs from it by the morphology of the antenna: in T. signatum last antennomeres distinctly thinner than the two preceding antennomeres IX–X; whereas in T. norfolkiana sp. nov. the width of last three antennomeres is nearly equal (Fig. 2B).

Figure 2 Trogoderma norfolkiana sp. nov. Holotype : A, female genitalia; B, left antenna, dorsal; C, sclerites of bursa copulatrix (only one pair of sclerites is shown on the picture); D, pygidium.

Among 51 Trogoderma species (including cosmopolitan) described from Australia, T. norfolkiana sp. nov. is similar to Trogoderma maurulum Blackburn, 1903 but differs from it by the following characters: in T. maurulum integument of pronotum is black covered with unicolour light brown pubescence; elytral integument brown with one narrow and poorly marked fascia of white pubescence; female’s last antennomere twice as long as wide; whereas in T. norfolkiana sp. nov. integument of pronotum is dark-brown covered with whitish pubescence along anterior margin and in angles near latero-posterior margins; elytral integument dark-brown with whitish pubescence forming three indistinct bands of variable width and shape; width and length of last antennomere is nearly equal.

Description

Body convex and elongated (nearly twice as long as wide) (Fig. 1A–D). Measurements for holotype: length from anterior margin of pronotum to apex of elytron 3.0 mm, median length of pronotum 0.6 mm, maximum width of pronotum 1.3 mm, length of elytron 2.4 mm, maximum width across elytra 1.5 mm. Dorsal and ventral pubescent suberect, whitish and brown. Head slightly visible from above; integument of head dark-brown; punctures of frons crater-like and shallow; diameter of each puncture equal to about 1.5 times diameter of facet of eye. Median ocellus is present. Eyes tan, large and convex with medial margin slightly sinuate. Antennal fossa occupying nearly all of hypomeron except for small projecting triangular area at antero-medial angle (ratio of length of antennal fossa to length of lateral margin of pronotum (hypomeron) is 0.8 : 1.0); floor of fossa microscopically punctate. Antenna has 11 antennomeres (Fig. 2B). Antennal club with five antennomeres; shorter than the flagellum (Fig. 2B). All antennomeres brown (but antennomeres VII–XI slightly darker (Fig. 2B)), and are covered with erect brown hairs. Pronotum dark-brown with punctation shallower than those on head; surface between punctures smooth and shining; lateral margins raised (slightly visible from above); covered by whitish and brown pubescence (Fig. 1A, C). Whitish pubescence present along anterior margin and in angles near latero-posterior margins (Fig. 1A, C). Elytra dark-brown; entire area is distinctly punctured; punctation deeper than those on pronotum. Pubescence of elytra consisting of whitish and brown hairs (Fig. 1A, C). Whitish pubescence forming three indistinct bands of variable width and shape. First band present around humeral calli in the anterior part of elytra. Second incomplete, under humeral calli at nearly half length of elytron, extending from lateral margin to half width of elytron (not reaching the sutura). Third band incomplete, close to apices of elytron in two-thirds of elytral length. Abdominal ventrites I–V with surfaces of integument dark-brown, sparsely punctured, and covered by light brown (tan) pubescence (Fig. 1B, D). Visible ventrite I with two oblique striae on each side extending from anterior margin of ventrite. Legs brown; trochanters, coxae and femora are dark-brown; tibiae and tarsi are lighter than other parts. Tibiae without tibial teeth on dorsal margin. Pygidium as in Fig. 2D. Female genitalia as in Fig. 2A. Bursa copulatrix with five sclerites (Fig. 2A, C). Male unknown.

Variability

Colour of integument brown to dark-brown; size varies as follows: TL 2.6–3.2 mm, PL 0.5–1.0 mm, PW 1.0–1.6 mm, EL 2.0–2.6 mm, EW 1.3–1.8 mm.

Etymology

The specific epithet is derived from the island where the species was discovered—Norfolk Island—a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia.

Associate Editor: Dr Cor Vink.

Acknowledgements

We express our gratitude to Dr Richard Leschen (NZAC) for the loan of types. This study was funded by the Internal Grant Agency [grant number B0118/004], Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague and Department the Institute of Environmental Biology, Faculty of Biological Science, University of Wrocław [grant number 1076/S/IBŚ/2015].