Crypturgus hispidulus Thomson, 1870

Digirolomo, Marc F. & Sevigny, Joseph L., 2023, A palearctic bark beetle, Crypturgus hispidulus Thomson (Coleoptera: Curculionidae: Scolytinae), new to North America discovered in New England, U. S. A., Zootaxa 5325 (3), pp. 429-435 : 431-433

Crypturgus hispidulus Thomson, 1870

Figures 2A , 3A

Crypturgus hispidulus Thomson, 1870: 338 .

Crypturgus maulei Roubal, 1910: 203 .

Diagnosis: Crypturgus hispidulus may be distinguished from other members of the genus by the combination of a subreticulate pronotum, long erect interstrial setae on the disc and sides of the elytra (which may be absent in particularly worn specimens), width of strial punctures and interstriae approximately equal, and females lacking a spongy patch on the elytral declivity. It is very similar to C. pusillus ( Fig. 2B , 3B ), which has a slightly shinier pronotum, nearly glabrous elytral disc, and smaller strial and interstrial punctures.

Morphology: Length 1.1–1.3 mm, 2.7 times as long as wide; color dark brown. Frons convex; surface reticulate, punctures fine; vestiture sparse, inconspicuous. Pronotum 1.1 times as long as wide; widest slightly behind middle, sides moderately arcuate, converging equally anteriorly and posteriorly, anterior margin slightly more narrowly rounded than posterior margin; surface of disc subreticulate and shining, becoming more reticulate toward margins; punctures moderately coarse, deep, separated by 1–2x their diameter; vestiture hairlike setae originating from punctures, evenly distributed. Elytra 1.8 times as long as wide, 1.8 times as long as pronotum; sides varying from straight and parallel on more than basal two-thirds to slightly arcuate and wider on apical two-thirds, evenly rounded behind; striae not impressed, punctures subequal in width to interstriae, deep; interstriae shining, interstrial punctures conspicuous, diameter about 0.5x as wide as strial punctures. Declivity convex, moderately steep; strial punctures on declivity smaller than on elytral disc. Elytral vestiture consisting of conspicuous, erect, uniseriate interstrial setae about as long as interstrial width, and finer strial setae subequal in length to interstrial setae but more recumbent. Females similar to males.

Distribution: Transpalearctic – Asia: China, Japan (Iturup, Kuril Islands, ownership disputed with Russia), North Korea, Russia, Turkey; Europe: Austria, Belarus, Bulgaria, Czechia, Denmark, Estonia, Finland, Germany, Hungary, Italy, Latvia, Lithuania, Netherlands, Norway, Poland, Russia, Slovakia, Slovenia, Sweden, Switzerland, Ukraine (Bright 2021; Jurc 2003; Krivolutskaya 1973, Kumbaşli et al. 2018).

New North American records: UNITED STATES: MAINE: Cumberland Co., Portland, Peak’s Island , 43.65608°, - 70.19087°, 7 Jul 2022, M.F. DiGirolomo, beating foliage of recently windthrown Picea rubens (1, DFOC) ; Franklin Co., Farmington , 6 Jun 2006, funnel trap, PSB Survey (1, MFS) ; Kingfield, Mt. Abraham , 44.9774°, -70.3058°, 19–28 May 2021, F.G. Guarnieri, funnel trap, α-pinene (1, MFDC) ; 1–7 Jun 2021, F.G. Guarnieri, funnel trap, α-pinene (1, MFDC) ; Hancock Co., 3.2 km SSE Ellsworth , 44.52016°, -68.39542°, 85 m, 22 May–4 Jun 2013, S. Bonstedt, black cross-vane panel trap, BSF#51541 (2, CMNH 642637-38 ) ; 1.3 km NE Somesville , 44.36794°, -68.32085°, 17 m, 21 May–4 Jun 2013, S. Bonstedt, black cross-vane panel trap, BSF#51549 (1, CMNH 642639 ) ; 4.2 km SSE Southwest Harbor , 44.24409°, -68.30743°, 33 m, 3–19 Jun 2014, S. Bonstedt, black cross-vane panel trap, BSF#56605 (1, CMNH 639311 ) ; 19 Jun–1 Jul 2014, S. Bonstedt, black cross-vane panel trap, BSF#56606 (2, CMNH 639315 &17) ; 0.8 km N Trenton , 44.44554°, -68.37176°, 25 m, 22 May–4 Jun 2013, S. Bonstedt, Lindgren funnel trap, BSF#51459 (1, CMNH 642640 ) ; 6.3 km SSE Winter Harbor , 44.34011°, -68.0611°, 19 m, 25 May–8 Jun 2016, G. Gamester, R. Nyce, black cross-vane panel trap, BSF#67506 (1, CMNH 701653 ) ; Penobscot Co., 4.8 km SE Hermon , 44.79078°, -68.85939°, 51 m, 15–24 May 2017, J. Nicolelli, Lindgren funnel trap, BSF#72896 (1, CMNH 710290 ) ; Piscataquis Co., T6 R10 WELS, Baxter State Park , 46.19475°, -69.06703°, 12 Jun 2014, M.F. DiGirolomo, modified funnel trap, EtOH, α-pinene, ipsenol, ipsdienol (1, MFS) ; Somerset Co., Bigelow Preserve , 45.1706°, -70.2526°, 14 May–2 Jun 2021, F.G. Guarnieri, funnel trap, α-pinene (1, JPBC) ; 2–10 Jun 2021, F.G. Guarnieri, funnel trap, α-pinene (1, JPBC) ; NEW HAMPSHIRE: Carroll Co., Bartlett Experimental Forest , 44.07414°, -71.29091°, 29 Jul 2020, K.J. Dodds, green funnel trap, syn-2,3-hexanediol, 3-hydroxyhexan-2-one, 3-hydroxyoctan-2-one, EtOH (1, DFOC) ; 17 May 2021, K.J. Dodds, green funnel trap, syn-2,3-hexanediol, 3-hydroxyhexan-2-one, 3-hydroxyoctan-2-one, EtOH (1, DFOC) ; Jun 2021 – 20 Apr 2022, K.J. Dodds, emergence chamber, Picea rubens (4, NMNH; 9, DFOC) .

Biology and hosts. As with other members of the genus, C. hispidulus typically gain entry to the host cambium from existing galleries of other beetle species, and has been found associated with Polygraphus poligraphus L. and Pityogenes chalcographus (L.) ( Nikulina et al. 2015). It has not been reported as a pest in any of the literature searched. Eurasian hosts include Abies sibirica , Larix decidua , Picea abies , Picea ajanensis , Picea obovata , Picea jezoensis , Pinus brutia , Pinus koraiensis , Pinus mugo , Pinus nigra , Pinus pumila , Pinus rotundata , and Pinus sylvestris (Stark 1952; Krivolutskaya 1973; Grüne 1979; Pfeffer 1995; Kumbaşli et al. 2018). It is common on fallen spruce trees ( Nikulina et al. 2015). In North America it has been found emerging from Picea rubens logs, and beaten from the foliage of recently windthrown P. rubens trees.

To accommodate C. hispidulus in Wood’s (1982) key to North American Crypturgus , couplet 1 may be modified as follows:

1. Pronotal disc subreticulate, lines radiating from punctures only; female without spongy area on elytral declivity......... 1a

1’. Pronotum uniformly, strongly reticulate; female with a spongy area on elytral declivity............................. 2

1a(1). Elytral disc and sides with interstrial rows of long, erect setae ( Fig 2A ); strial punctures about same width as interstriae ( Fig. 3A ); 1.1–1.3 mm .................................................................... Crypturgus hispidulus

1a(1)’. Elytral disc nearly glabrous (short, fine hairs may be present), fine setae restricted mostly to the elytral margins ( Fig 2B ); strial punctures about 0.5x width of interstriae ( Fig 3B ); 1.0– 1.2 mm ................................. Crypturgus pusillus

Figures

FIGURE 2. Dorsal habitus of Crypturgus spp. A Crypturgus hispidulus B Crypturgus pusillus. Scale bar: 0.5 mm.

FIGURE 3. Elytral disc of Crypturgus spp. A Crypturgus hispidulus B Crypturgus pusillus. Arrows indicate width of striae and interstriae.