Xylothrips religiosus ( Boisduval, 1835 )

Liu, Lan-Yu, 2021, A review of the powderpost beetle genera Xylothrips Lesne, 1901 and Calophagus Lesne, 1902 (Coleoptera: Bostrichidae: Bostrichinae: Xyloperthini), European Journal of Taxonomy 746 (1), pp. 130-147 : 138-140

Xylothrips religiosus ( Boisduval, 1835)

Figs 1E–F , 3

Apate religiosa Boisduval, 1835: 460 .

Apate destructor Montrouzier, 1856: 33 . Synonymy in Lesne 1901: 624.

Apate lifuana Montrouzier, 1861: 267 . Synonymy in Lesne 1896: 335.

Apate geoffroyi Montrouzier, 1861: 266 . Synonymy in Borowski & Węgrzynowicz 2019: 82.

Apate religiosae – Fairmaire 1850: 50 (in part).

Diagnosis

The species is distinguished from X. flavipes by the slightly smaller size and darker body, and the often entirely dark brown, fronto-clypeal suture with a median fovea. The middle of the lateral and posterior parts of the pronotum behind the asperities of recumbent teeth with extremely fine, moderate to sparse punctures. Punctures stronger on the disc of the elytra, three pairs of tubercles on the upper margin of the declivity not as developed as in X. flavipes , the lateral callus not converging into the lateral margin of the declivity. Elytral suture slightly raised, not as swollen as in X. flavipes , the apical angles raised a little without tubercles beneath the margin.

Material examined

Borowski & Węgrzynowicz (2007) suggested that the type material of Apate religiosa could be in NHMUK and the Montrouzier types should be deposited in MNHN, but after the author examined 427 specimens of X. religiosus in NHMUK (plus one under X. geoffroyi ), she did not find any one bearing a ‘type’ label. Similarly, no type specimens of Xylothrips were found in MNHN. Hence, the type material was not located, but the species is well-known in the archipelagos of the South Pacific Ocean, and in Australia.

The author has examined numerous specimens identified by Lesne and Vrydagh, and more than 1170 specimens were checked at several museums ( RBINS, MIZPN, MNB, MTM, NHMUK, NMBS, NME, NMPC, NMS, NMW, SDEI, SNSD and ZSM) and in private collections ( LYL, MAIC and PZP), but detailed locality data were not recorded. The specimens were mainly from Papua New Guinea, New Caledonia and the archipelagos of the South Pacific Ocean.

Description

BODY. 5.5–8 mm long, about 2.2–2.35 times as long as wide, elongate. Entirely dark brown, except antennae, head and femora testaceous.

HEAD. Clypeus finely and densely punctured, almost glabrous in middle, concave in a wide arc in front with a tuft of erect, long and yellowish-red hairs on both sides of clypeus. Fronto-clypeal suture distinct, with median fovea. Frons with puncturation denser than on clypeus, slightly rough, covered by fairly long, fine pubescence directed upwards. First antennomere longer than wide, second antennomere shorter, each funicle segment with a rim of long hair on middle, total length of funicle as long as or shorter than first antennomere of antennal club, first two antennomeres of antennal club about 1.5 times as long as wide, last antennomere rather elongated, about 3 times as long as wide. Club matt, without clear sensory impression areas or erect hairs ( Fig. 1E ).

PRONOTUM. 1.25–1.35 times as wide as long, fairly strongly narrowed in anterior third, widest in basal part; a distinct upwardly-directed uncinate tooth on anterolateral angle and a series of upward-directed teeth behind form lateral border of rasp on anterior half of pronotum, teeth gradually smaller and less erect towards summit of pronotum, posterior border of rasp formed by small tubercles or granules, bearing dense, white, short, recumbent pubescence between and on teeth ( Figs 1E , 3A ); area above anterior margin between uncinate teeth densely, finely and more or less roughly punctured; median and posterior areas of pronotum shiny with fine, sparse punctures, posterolateral areas with denser punctures and short, white-yellowish hairs; sides evenly rounded behind rasp; a distinct ridge-like lateral carina extends to basal margin of pronotum to form tip of posterolateral angles ( Fig. 1F ).

ELYTRA. 1.8–1.95 times as long as pronotum, 1.4–1.55 times as long as wide, parallel-sided at disc and widest at middle of declivity. Elytra shining, with sparse, fine and shallow punctures on disc, becoming deeper and larger towards lateral and posterior parts, upper half of declivity with strongest punctures. Entirely glabrous, with tiny white hairs along lateral and apical margins. Upper margin of elytral declivity with three pairs of tubercles, middle one largest and most strongly projecting, with pointed tip, other two forming short ridges with round ends, infero-lateral callus not extending to lower lateral margin of elytra ( Fig. 3C–D ). Elytral suture raised from middle of disc, gradually more swollen and thickest at upper margin of declivity, apex of declivity slightly projected.

ABDOMEN. Ventral side vestiture with dense, white or reddish yellow pubescence, last ventrite with narrow pleural pieces along margin.

LEGS. Dense, short golden hairs on ventroposterior margins of posterior femora. External face of pro- and mesotibiae narrowly grooved, not narrowed towards apex. Segments 2 and 3 of anterior tarsi distinctly wider than others.

Male

HEAD. Frons transversely convex, densely and very finely punctured, a small shining callus in middle ( Fig. 3A ); yellow, erect pubescence covers areas from callus to eyes and fronto-clypeal suture, short and recumbent toward middle and gradually longer towards eyes, with a tuft of long, erect hairs next to inner margin of eyes. Clypeus with a transverse band of upwardly directed hairs towards base with a narrow median line and a tuft of long, erect hairs on both sides of clypeus ( Fig. 1E ).

Female

HEAD. Frontal crown of hairs very thick, forming arc of a circle or a very wide V, fairly distant laterally from eyes. Clypeal tufts of hairs as long as those on frons.

Remarks

Montrouzier (1861) described Apate lifuana and Apate geoffroyi from the Lifu and Art Islands of New Caledonia, respectively. Waterhouse (1888) transferred Apate lifuana to Xylopertha , noting that material he examined bore the name religiosa Dej. Lesne (1896) later synonymised Xylopertha lifuana with Xylothrips religiosus .

Borowski & Węgrzynowicz (2019) synonymised Apate geoffroyi with X. religiosus without examination of the type material, but inferred that Montrouzier misinterpreted the differences between the sexes.

Lesne (1901) mentioned that specimens with reduced marginal tubercles of the elytral declivity are found in New Caledonia, and that one specimen from the Cape York peninsula, Australia was notable for the much stronger elytral punctures than found in other specimens, the very fine, but very distinct, punctures in the middle of the pronotal disc, and the weaker projection of the lowermost marginal tubercle of the elytral declivity. Variations in the punctures on the posterior half of the pronotum and in the development of the marginal tubercles of the elytral declivity were often found during the present study.

Biology

In Tahiti, X. religiosus has been recorded from the breadfruit tree ( Moraceae : Artocarpus altilis (Parkinson) Forsberg ), and in the ‘bourao’ ( Malvaceae : Hibiscus tiliaceus L.). In Melanesia, the species attacks many trees, even the hardest ones, but its multiplication is reduced by a clerid beetle of the genus Cylidrus . The adults fly in the evening and are attracted to light ( Lesne 1901).

Distribution

Indonesia, Papua New Guinea, Australia, New Caledonia and the archipelagos of the South Pacific Ocean. This species has been introduced to USA, Africa and Europe ( Borowski & Węgrzynowicz 2019).

Figures

Fig 3. Xylothrips religiosus (Boisduval, 1835), ♀ (LYL). A. Frontal view. B. Dorsal view. C. Declivity. D. Lateral view of declivity. E. Lateral view. Scale bars = 1 mm (upper scale for B, E; lower scale for A, C–D).

Fig. 1. A–B. Calophagus pekinensis Lesne, 1902, ♀ (SNSD). A. Anterolateral view showing the antennae, with two strips of golden hairs on sides. B. Lateral view of head and pronotum showing absence of lateral carina on pronotum. C–D. Xylothrips flavipes (Illiger, 1801), ♂ (LYL). C. Frontal view showing the antennae, matt without sensory areas. D. Lateral view of head and pronotum showing clear lateral carina on pronotum. E–F. Xylothrips religiosus (Boisduval, 1835), ♂ (LYL). E. Frontal view showing the antennae, matt without sensory areas. F. Lateral view of head and pronotum showing clear lateral carina on pronotum. Scale bar = 1 mm.