Microrhagus breviangularis, , 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 : 13-14

Distribution. Microrhagus breviangularis is known from USA: Florida, Indiana, and Wisconsin.

Biology. In Florida two specimens have been taken by Malaise trap placed in an unburned scrub oak/ saw palmetto ecosystem. One beetle was taken in a clear bottle trap baited with rotting fruit in Indiana. In Wisconsin, I found M. breviangularis in a variety of forest systems including northern hardwood swamp, northern mesic forest, southern hardwood swamp, and southern mesic forest. Nine specimens were taken from a Malaise trap placed in a deciduous forest in Ozaukee County. One larva was found in a moist, white rotten Quercus log in 2012. Other larvae were found in a rotten shagbark hickory ( Carya ovata (Miller) K. Koch ; Juglandaceae ) and another undetermined rotten log. 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 at least 2.5–3.0 cm beneath the surface. Larvae construct a pupal chamber near the surface and assume a U-shaped position. I observed no noticeable difference between previous instars and the prepupal larval form. Pupation requires about two to three weeks. Most recently, a few adults were collected from purple prism traps while surveying for the presence of Emerald Ash Borer beetle during mid-July through mid-September in northeastern Wisconsin.

Two adults emerged from separate pieces of rotten oak wood on 26 February 2013. Two other adults emerged on 8 February 2014. These adults were placed in a vial to observe their behavior. Adult M. breviangularis 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: “ U.S.A.: WI: Ozaukee Co., UW-Mil. Field Station , 43.38567ºN /- 88.02638ºW, WGS84, 02–09 July 2013, Daniel K. Young ” / “ HOLOTYPE:, Microrhagus , breviangularis, Otto , det. R.L. Otto, 2014 ” (♂ handwritten behind species name on label)[red printed label] . Allotype, female, with label data: “WI: Shawano Co., along Carroll Road , N44.78156º, W- 88.34259º, EABT013113, 11 August 2010, Robert L. Otto ” / “ Taken from EAB prism trap baited with manuka oil” / “ ALLOTYPE: Microrhagus , breviangularis, Otto , det. R.L. Otto, 2014 ” (♀ handwritten behind species name on label) [yellow printed label] . Holotype and allotype are in WIRC.

Paratypes. 22 adults and 10 larvae, from the following localities: 2 adults, FLORIDA: Seminole Co.: Econ Wild. Area , IV–15–2000, Trevor Smith ( FSCA) ; 1 adult, INDIANA: Montgomery Co.: Shades State Park , May 30–July 6, 2011, Kyle E. Schnepp ( KESC) ; 2 adults, 3 larvae, WISCONSIN: Dane Co.: Festge Park , 18 September 2012, 1 October 2013, Robert L. Otto ( GERP) ; 1 larva, LWRSWA– Mazomanie Unit , 23 September 2012 ; 2 adults, 6 larvae, Turville Point Preserve , 14 September 2013, Robert L. Otto ( GERP, WIRC) ; 2 adults, Door Co.: N45.08352122°, W087.16285209°, September 21 2009, September 22 2009, Robert L. Otto ( WIRC) ; 1 adult, Forest Co.: along Windsor Dam Road , 1 September 2009, Robert L. Otto ( GERP) ; 1 adult, along Spur Ln. , 9 September 2009, Robert L. Otto ( WIRC) ; 1 adult, along Ross Lake Rd. , 9 September 2009, Robert L. Otto ( WIRC) ; 7 adults, Ozaukee Co.: UW-Mil. Field Station , 43.38567ºN /- 88.02638ºW, WGS84, 02–09 July 2013, 16–22 July 2013, 06–13 August 2013, Daniel K. Young ( WIRC) ; 1 adult, UW-Mil. Field Station , 43.38295ºN /- 88.02534ºW, WGS84, 09–16 July 2013, Daniel K. Young ( WIRC) ; 1 adult, Shawano Co.: along Hazel Road , 9 August 2010, Robert L. Otto ( GERP) ; 1 adult, along Old WI-22, 19 July 2010, Robert L. Otto ( WIRC). Each specimen labeled: “ PARATYPE:, Microrhagus , breviangularis, 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 deposited in FSCA, GERP, KESC and WIRC. Larval paratypes are deposited in GERP and WIRC .

Etymology. The name of the new species is derived from the shorter hind angles of the pronotum.