Microrhagus lecontei, , Otto, 2015

Otto, Robert L., 2015, Eucnemid larvae of the Nearctic region. Part V: Fifth instar larval descriptions for eight species of Microrhagus Dejean, 1833 (Coleoptera: Eucnemidae: Melasinae: Dirhagini), with descriptions of four new species and notes on their biology, Insecta Mundi 2015 (421), pp. 1-46 : 20-21

Distribution. Microrhagus lecontei has been taken in USA: Indiana, Kansas, and Wisconsin.

Biology. Two beetles were taken from a Lindgren funnel trap set in Tippecanoe County, Indiana. One beetle was taken from a black panel trap baited with EtOH in Morgan Co., Indiana. In Kansas, beetle specimens have been taken from a Malaise trap and a canopy trap. In Wisconsin, I found M. lecontei in a variety of forest systems including floodplain forest, northern hardwood swamp, northern mesic forest and northern wet-mesic forest. All larvae were extracted from a very wet, grey rotten Quercus (Fagaceae) log in 2013. The heavily rotten log was located 6.06 meters from the shoreline of Lake Waubesa at McDaniel Park in McFarland. The plant community was classified as a floodplain forest dominated with green ash ( Fraxinus pennsylvanicus Marshall ; Oleaceae ) with silver maples ( Acer saccharinum Linnaeus ; Aceraceae ), basswood ( Tilia americana Linnaeus ; Tiliaceae ) and oaks as associates. Searching in conifers has yielded no larvae, which may indicate this species is a deciduous specialist.

I observed larvae tunneling along the wood grain, leaving no trails behind them. Many larvae were extracted near the surface, no more than 2.5 cm beneath the surface. Fourteen larvae, ranging from third to fifth instars were extracted from very wet pieces of wood. The striking feature observed in some larvae were enlarged areoles present on some abdominal segments. These enlarged areoles may be attributed to an adaptive strategy of boring into a wetter log as they constantly regulate water between themselves and the surrounding wet wood fibers. Some of the younger larvae have smaller areoles, compared to some of the fifth instars. Like many other observed species, larvae of M. lecontei construct a pupal chamber near the surface and assume a U-shaped position. I also observed no noticeable difference between previous instars and prepupal larval form. Pupation requires about two to three weeks. Most recently, many adults were collected from purple prism traps from late-June through mid-September in northeastern Wisconsin. During the mid to late 1970’s, collectors in Wisconsin have found M. lecontei in Malaise traps deployed in much of Wisconsin during their survey work on Gypsy Moths ( Lymantria dispar Linnaeus ; Erebidae ).

Eight adults emerged on 8 February 2014. All adults were placed in a small Ziploc® bag to observe their behavior. Like other eucnemid species, adult M. lecontei are capable of snapping into the air when placed on their backs. Adults were also observed to quiver their extended antennae while in captivity.

Type material. Holotype, male, with label data: “WI: Forest Co., along State Highway 55, N45.69989º / W88.86191º, 28 July 2009, Robert L. Otto ” / “ Taken from EAB prism trap baited w/ manuka oil” / “ HO- LOTYPE:, Microrhagus , lecontei, Otto , det. R.L. Otto, 2014 ” (♂ handwritten behind species name on label)[red printed label] . Allotype, female, with label data: “WI: Forest Co., along Double Bend Road , N45.74162° / W88.76381°, 20 August 2009, Robert L. Otto ” / “ Taken from EAB trap baited w/ manuka oil” / “ ALLOTYPE:, Microrhagus , lecontei, Otto , det. R.L. Otto, 2014 ” (♀ handwritten behind species name on label) [yellow printed label] . Holotype and allotype are in WIRC.

Paratypes. 24 adults and 14 larvae, from the following localities: 1, INDIANA: Morgan Co.: July 11–Aug. 3, 2010, Kyle E. Schnepp ( KESC) ; 2, Tippecanoe Co.: Ross Hills, Lindgren , June 7–28, 2013, col. Gareth S. Powell ( GSPC) ; 1, KANSAS: Douglas Co.: 2 mi NW Baldwin , 38° 48.586’N, 95° 12.560’W, 12–26–VI–2006 ( SEMC) ; 1, Jefferson Co.: The Falin Property, 1.5 km N jct. 94th Street and Kingman Rd. , 39° 13.38’N, 95° 24.24’W, 10–25–VII–2004 ( SEMC) ; 8 adults and 14 larvae, WIS- CONSIN: Dane Co.: McDaniel Park , 22 September 2013, 27 September 2013, Robert L. Otto ( GERP, WIRC) ; 1, Fond du Lac Co.: T46N R9E sec 16, 2–8 August 1977 ( WIRC) ; 1, Forest Co.: along Borske Rd , 17 August 2009, Robert L. Otto ( WIRC) ; 1, along Ross Lake Rd, 19 August 2009, Robert L. Otto ( WIRC) ; 1, along Old Hwy 55, 24 August 2009, Robert L. Otto ( WIRC) ; 1, Iowa Co. : T6N R5E sec. 1, 6–12 July 1976 ( WIRC) ; 1, Jackson Co.: T21N R4W sec. 33, 6–12 July 1976 ( WIRC) ; 1, Oconto Co.: along Mosling Rd , 22 June 2010, Robert L. Otto ( WIRC) ; 1, Oneida Co.: T46N R9W sec. 16, 12–19 July 1977 ( WIRC) ; 1, Ozaukee Co.: 43.38295ºN /- 88.02534ºW, WGS84, 09–16 July 2013, Daniel K. Young ( WIRC) ; 1, 43.38567ºN /- 88.02638ºW, WGS84, 27 August –3 September 2013, Daniel K. Young ( WIRC) ; 1, Shawano Co.: along State Highway 32, 21 July 2010, Robert L. Otto ( WIRC). Each specimen labeled: “ PARATYPE:, Microrhagus , lecontei, Otto , det. R.L. Otto, 2014 ” (either ♂ or ♀ handwritten behind species name on each label)[yellow printed label] placed beneath the top label or inside the alcohol vial with the larval specimen. Larvae are of indeterminate sex. Adult paratypes are deposited in GERP, GSPC, KESC, SEMC and WIRC. Larval paratypes are deposited in GERP and WIRC .

Etymology. The name of the new species is dedicated to John LeConte, the father of American Coleopterology.