Stenhomalus taiwanus, MATSUSHITA

Holt, Brian D., 2016, Stenhomalus taiwanusMatsushita (Coleoptera: Cerambycidae) is New to the USA, The Coleopterists Bulletin 70 (1), pp. 134-136 : 134-136

STENHOMALUS TAIWANUS MATSUSHITA ( COLEOPTERA : CERAMBYCIDAE ) IS NEW TO THE USA

BRIAN D. HOLT Alabama Department of Conservation and Natural Resources, State Lands Division Natural Heritage Section, 64 North Union St. Montgomery, AL 36130, U.S.A. [e-mail]

An unidentified species of Stenhomalus White has been intercepted at eastern ports in the USA in recent years. The first known interception occurred in Atlanta, Georgia in 1995, where two individuals were collected from wooden dunnage and the vouchers deposited in the Atlanta Port Collection. It is noted that the labels for the specimens are formatted differently and may represent two separate collections for that year ( Young 2010). The second report occurred on 5 July 2005 at the Nashville, Tennessee airport where a single specimen was collected from a shipment of woodware ( Young 2010). On 28 August 2009, Customs and Border Protection intercepted an adult Stenhomalus from a shipping container housing baskets at the Dundalk Marine Terminal, Port of Baltimore, Maryland. The individual was collected as a voucher and deposited at the Atlanta Port Collection. Each of the previously mentioned shipments originated from China (USCBP 2009; Young 2010). In 2012, a number of additional collections were confirmed from Vermont, Connecticut, and Clayton County, Georgia (Joel Floyd, in litt.).

Recent work on a checklist of the Cerambycidae of Alabama ( Holt 2013) yielded nine additional specimens of Stenhomalus , all representing domestic collections. Two specimens were photographed and the images distributed among cerambycid specialists, including Tatsuya Niisato who tentatively identified the specimens as either Stenhomalus cephalotes Pic or Stenhomalus taiwanus Matsushita. He stated that the host plants for S. taiwanus were species of Zanthoxylum L. ( Rutaceae ), a common stock source for Asian carvings and woodware. If the beetles were arriving in containers from China, they most likely represented S. taiwanus (T. Niisato, in litt.).

Four specimens were submitted to the USDA Animal and Plant Health Inspection Service – Plant Protection and Quarantine for identification verification. Unfortunately, one specimen was lost in transit. The remaining three specimens were examined by the USDA Agricultural Research Service ( ARS) Systematic Entomology Laboratory and identified as S. taiwanus ( Fig. 1 ), confirming the tentative identification previously made from photographs .

The holdings at several Alabama universities were accessed to check for unidentified, misidentified, or otherwise unreported specimens of S. taiwanus . Additional inquiries were made to institutions outside the state, including Mississippi Entomological Museum, University of Mississippi, USDA ARS in Mississippi (cerambycid specimens held at Colorado State University), University of Georgia, and the Florida State Collection of Arthropods. No additional specimens of S. taiwanus were located.

Collection data for all nine specimens collected in Alabama and Georgia are as follows: USA: ALABAMA: Colbert Co., 11.v.2009, Muscle Shoals off Woodward Ave., N34.73577 W-87.66717, at hotel lights, T. Wayne Barger (1); Colbert Co. , 19.viii.2014, Muscle Shoals off Woodward Ave., N34.73577 W-87.66717, at hotel lights, T. Wayne Barger (1); Jefferson Co. , 25.viii.2011, Birmingham- Southern College campus, N33.514 W-86.858, light trap, Peter Van Zandt (2); Lauderdale Co. , 12.vi.2013, Rogersville at Joe Wheeler State Park , N34.80470 W-87.33051, beaten from Vitis sp. , Brian D. Holt (1); Montgomery Co. , 28.vii.2012, Montgomery at Capital Heights off Hwy 9, N32.38480 W-86.27395, at porch light, Brian D. Holt (1); Montgomery Co. , 1.viii.2012, Montgomery at Capital Heights off Hwy 9, N32.38480 W-86.27395, at porch light, Brian D. Holt and A. Nicole Holt (1); Montgomery Co. , 9.vi.2014, Montgomery at Capital Heights off Hwy 9, N32.38480, W-86.27395, Brian D. Holt (1). GEORGIA: Gwinnett Co., 29.viii. 2012, Lawrenceville, William D. Newton (1). New country record .

All specimens are held in the author’ s collection excluding the one lost in transit for identification. An overview of the collection locations is depicted in Fig. 2 .

THE COLEOPTERISTS BULLETIN 70(1), 2016 135

In the eastern United States, S. taiwanus most closely resembles our native Obrium maculatum (Olivier) ( Fig. 1 ). It differs from O. maculatum by the presence of erect and decumbent setae on the dorsum and long setae apically on the third and fourth antennomeres ( Gressitt 1935).

Stenhomalus taiwanus is native to Korea, Japan, Taiwan, and China (Joel Floyd, in litt.). As stated previously, Zanthoxylum serves as a host, and S. taiwanus has been recorded from several species including Zanthoxylum ailanthoides Siebold & Zuccarini , Zanthoxylum piperitum (L.), and Zanthoxylum bungeanum Maximowicz ( Makihara 1977; Iwata 1991; Zhang et al. 2009). The genus Zanthoxylum is represented by approximately 225–250 species across Africa, the Americas, Asia, and Australia ( Weakley 2013). In Alabama and Georgia, where the domestic collections of S. taiwanus were made, two species of native Zanthoxylum are present: Zanthoxylum clava-herculis L. and Zanthoxylum americanum P. Miller ( Kral et al. 2011) . Given the number of recent domestic collections of S. taiwanus and the beetle’ s apparent preference for species of Zanthoxylum as a host, it is not unreasonable to believe this species is currently established in the southeastern United States.

Figures

Fig. 1. Habitus comparison of Stenhomalus taiwanus (left) and Obrium maculatum (right).

Fig. 2. Collection locations for Stenhomalus taiwanus in Alabama and Georgia.