Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae) Found in South Dakota, U.S.A.

Hippodamia variegata (Goeze) is a Palaearctic coccinellid that was first reported from North America in Québec, Canada (Gordon 1987). It has radiated into much of eastern North America (Wheeler and Stoops 1996; McCorquodale 1998; Ellis et al. 1999; Gardiner and Parsons 2005; Day and Tatman 2006), and its geographic range expansion had progressed to western Wisconsin by 2009 (Williams and Young 2009). We have monitored populations of lady beetles in eastern South Dakota over the past several years through 2009, but H. variegata was not detected (Hesler and Kieckhefer 2008; Hesler and Petersen 2008; unpublished data). Herein we document the presence ofH. variegata in South Dakota from continued collection efforts in 2010. Number of specimens collected and their depository are given between brackets with JGLC = J. G. Lundgren Collection and NCARL = North Central Agricultural Research Laboratory. New State Records. SOUTH DAKOTA, Brookings County: Eastern South Dakota Soil and Water Research Farm (ESDSWRF), 44.3 N, 96.8 W, Elymus trachycaulus (Link) Gould ex Shinners (Poaceae)), 18-V-2010, slender wheatgrass plot, J. G. Lundgren [3 adults JGLC]; ESDSWRF, 2 km north of Brookings, alfalfa plot B13, 26-V-2010, E. A. Beckendorf and P. A. Rozeboom [2 adults NCARL]; NCARL, 1 km north of Brookings, 26-V-2010, spring wheat plot A12, G. McNickle [1 adult NCARL]; ESDSWRF, 2 km north of Brookings,1-VI-2010, alfalfa plot B8, E. A. Beckendorf and P. A. Rozeboom [1 adult NCARL]; NCARL, 1 km north of Brookings, 3-VI-2010, alfalfa plot A15, E. A. Beckendorf and P. A. Rozeboom [1 adult NCARL]; NCARL, 1 km north of Brookings, 16-VI-2010, winter wheat plot A13, E. A. Beckendorf and P. A. Rozeboom [1 adult NCARL]; Brookings Prairie, 1 km south of Brookings, 16-VI-2010, E. A. Beckendorf and P. A. Rozeboom [1 adult, specimen lost]; NCARL, 1 km north of Brookings, 21-VI-2010, spring wheat plot A12, G. McNickle [1 adult NCARL]; ESDSWRF, 2 km north of Brookings, 22-VI2010, spring wheat plot C2, E. A. Beckendorf and P. A. Rozeboom [1 adult NCARL]; NCARL, 1 km north of Brookings, 22-VI-2010, winter wheat plot A13, E. A. Beckendorf and P. A. Rozeboom [1 adult NCARL]; 2 km north of Brookings, 23-VI-2010, alfalfa, G. McNickle [3 adults NCARL]; 2 km north of Brookings, 24-VI-2010, oats field B7, L. S. Hesler [1 adult NCARL]; ESDSWRF, 2 km north of Brookings, 24-VI-2010, alfalfa plot B7, G. McNickle [3 adults NCARL], 2 km north of Brookings, 25-VIII-2010, alfalfa, G. McNickle [1 adult NCARL]. Hippodamia variegata was associated with English grain aphids and bird cherry-oat aphids in wheat, and with pea aphids in alfalfa in our survey. Previous surveys in other areas of North America recorded H. variegata from wheat and alfalfa (Ellis et al. 1999; Day and Tatman 2006). Potential prey in slender wheatgrass and the prairie was undetermined in our survey, but H. variegata has also been associated previously with plant species that occur in prairies (Ellis et al. 1999). The detection of H. variegata in South Dakota was unexpected this soon, as the nearest records of this species occurred approximately 400 km away in western Wisconsin in 2009 (Williams and Young 2009). The collections of 21 H. variegata during summer 2010 indicate that this species is now well established in Brookings County, South Dakota. In addition to weekly sampling of lady beetles in crop fields in Brookings County during the summer of 2010, other surveys for lady beetles in South Dakota did not find H. variegata at a nature preserve in Minnehaha County on 4 June or one in Beadle County on 31 July, suggesting a still limited local distribution. Additional surveys are needed to determine the extent to which H. variegata is present in South Dakota and to follow its geographic dispersion. Hippodamia variegata was released in Nebraska and several other Midwestern states, but not South Dakota, from 1987 to 1994 for intended biological control of the Russian wheat aphid (Flanders et al. 1991; Prokrym et al. 1998). However, the releases were deemedunsuccessful in establishingH. variegata (Ellis et al. 1999). As H. variegata was not released