Xyleborus affinis Eichhoff, 1868

Smith, Sarah M., Beaver, Roger A. & Cognato, Anthony I., 2020, A monograph of the Xyleborini (Coleoptera, Curculionidae, Scolytinae) of the Indochinese Peninsula (except Malaysia) and China, ZooKeys 983, pp. 1-442 : 1

Xyleborus affinis Eichhoff, 1868 Fig. 88A, B, I

Xyleborus affinis Eichhoff, 1868b: 401.

Xyleborus affinis fuscobrunneus Eichhoff, 1878b: 372. Synonymy: Schedl 1959: 504.

Xyleborus affinis mascarensis Eichhoff, 1878b: 372. Synonymy: Wood 1960: 71.

Xyleborus affinis parvus Eichhoff, 1878b: 372. Synonymy: Wood 1960: 71.

Xyleborus sacchari Hopkins, 1915a: 64. Synonymy: Wood 1982: 830.

Xyleborus subaffinis Eggers, 1933a: 36. Synonymy: Schedl 1959: 504.

Xyleborus societatis Beeson, 1935a: 120. Synonymy: Beaver 1991: 94.

Xyleborus proximus Eggers, 1943: 66. Synonymy: Schedl 1963a: 331.

Type material.

Holotype Xyleborus sacchari (NMNH). Holotype Xyleborus societatis (BPBM).

New records.

Cambodia: Kampong Speu, Aoral Wildlife Sanctuary, 11°42'10.75"N, 103°52'54.9"E, 200 m, dry dipterocarp forest, 16.xi.2013, O. Košulíc (MNHP, 1). China: Hainan, Changjiang, Bawangling Natl For. Park, 19.117N, 109.080E, 119 m, 5.xii.2016, Tian-Shang, Lv-Jia (RABC, 1). S Yunnan, Xishuangbanna, 20 km NW Jinghong, vic. Man Dian (NNNR), 22°07.80'N, 100°40.0'E, 740 m, rubber plantation, 23.v.2008, A. Weigel (NKME, 1); as previous except: 23 km NW Jinghong, vic. Na Ban (NNNR), 22°09.49'N, 100°39.92'E, transit zone, 730 m, 15.vi.2008, A. Weigel (NKME, 1); as previous except: forest, EKL, 26.iii.2009, L. Meng (RABC, 1); as previous except: 28 km NW Jinghong, vic. An Ma Xi Zhan (NNNR), 22°12'N, 100°38'E, 700 m, forest, EKL, 30.x.2008, A. Weigel (RABC, 1). India: Meghalaya, Nokrek N. P., 3 km S Darbokgiri, 25°27'N, 90°19'E, 1400 m, 26.iv.1999, Dembický, Pacholátko (RABC, 1). Tamil Nadu, Pondicherry, 10 km N. Auroville, 2.ii-2.iii.2011, F. Burger (NKME, 1). Laos: Vientiane, Ban Van Eue, 15.ii.1966, native collector (BPBM, 2); as previous except: 15.v.1966 (BPBM, 1). Myanmar: Yangon Division, Highland Lodge, 16°51.29'N, 96°08.29'E, 11.v.1998, J. Slovinsky, ex uv light trap in semi-tropical urban rainforest (CASC, 1). Vietnam: Dong Nai, Cat Tien N.P., 11.43771, 107.42253, 142 m, 21.ii.2017, VN84, A.I. Cognato, T.A. Hoang, ex 6-15 cm diameter branches (MSUC, 3). Lao Cai, Hoang Lien N.P., 22.35, 103.77, 1500 m, 21.v.2019, VN152, S.M. Smith, A.I. Cognato, ex FIT (MSUC, 4). Ninh Binh, Doi Vac, Cuc Phuong, 10-16.ix.2013, J.B. Heppner (FSCA, 2).

Diagnosis.

2.2-2.5 mm long (mean = 2.32 mm; n = 5); 2.56-3.14 × as long as wide. This species is distinguished by the protibiae obliquely triangular, broadest at distal 1/3; declivity shagreened, dull (specimen must be dry); small size; declivital interstriae 1 and 3 armed with sparse uniformly sized small granules, interstriae 2 sparsely granulate at declivital summit; and declivity not appearing sulcate.

Similar species.

Xyleborus cognatus , X. ferrugineus , X. festivus , X. perforans , X. pfeilii , X. volvulus .

Distribution.

Probably native to tropical America ( Wood 1977; Gohli et al. 2016), but now in temperate and tropical regions around the world. Less common in the Oriental region than in Africa and the Americas, but sometimes locally abundant. Recorded in the study region from Cambodia*, China* (Hainan, Yunnan), India (Meghalaya*, Tamil Nadu*, no state recorded), Laos*, Myanmar*, Nepal, Taiwan, Thailand, Vietnam*.

Host plants.

Strongly polyphagous ( Schedl 1963a, as Xyleborus mascarensis Eichhoff; Wood 1982).

Remarks.

The biology of the species is reviewed by Schedl (1963a). Schneider (1987) notes that more than one generation may inhabit the same gallery system, and describes the oral mycangia. Seasonal changes in numbers caught in traps have been related to temperature and rainfall in Africa ( Beaver and Löyttyniemi 1991; Madoffe and Bakke 1995), and in Central America ( Rangel et al. 2012). Flight height preference in Amazonia is described by Abreu et al. (2001). Laboratory rearing techniques, and the occurrence of delayed dispersal and alloparental care are discussed by Biedermann et al. (2009, 2011). Although its attacks are secondary, the species can be of economic importance due to its abundance and wide host range.

Figures

Figure 88. Dorsal, lateral and declivital view of Xyleborus affinis, 2.2 - 2.5 mm (A, B, I), X. bidentatus, 3.4 - 3.5 mm (C, D, J), X. cognatus, 2.8 - 3.1 mm (E, F, K), and X. ferrugineus, 2.5 - 3.1 mm (G, H, L).