Pyemotes tritici (Acari: Pyemotidae): a parasitoid of Agrilus auroguttatus and Agrilus coxalis (Coleoptera: Buprestidae) in the southwestern United States of America and southern Mexico

The straw itch mite, Pyemotes tritici Lagreze-Fossat and Montane (Acari: Pyemotidae), was discovered parasitising the goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), an invasive exotic species to California, United States of America, and the Mexican goldspotted oak borer, Agrilus coxalisWaterhouse (Coleoptera: Buprestidae), during surveys for natural enemies for a classical biological control programme for A. auroguttatus. Pyemotes tritici caused low levels of mortality to each species of flatheaded borer, but it will likely not be a good candidate for a biological control programme because it is a generalist parasitoid with deleterious human health effects. The straw itch mite, Pyemotes tritici LagrezeFossat and Montane (Acari: Pyemotidae), a common ectoparasitoid of Coleoptera, Lepidoptera, and Hymenoptera, was found parasitising the goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), in southern California and southeastern Arizona, United States of America and a congener, the Mexican goldspotted oak borer, Agrilus coxalis Waterhouse, in southern Mexico. Agrilus auroguttatus and A. coxalis were described in 1905 and 1889, respectively (Waterhouse 1889; Schaeffer 1905); synonymised by Hespenheide (1979); but then restored to species status by Hespenheide et al. (2011). Analyses of mitochrondrial DNA from populations in Arizona, California, and Mexico supported the species status of A. auroguttatus and A. coxalis (Coleman et al. 2012b). Agrilus auroguttatus is a flatheaded phloem and wood borer that has been linked to continuing southern California oak (Quercus Linnaeus (Fagaceae)) mortality (Coleman and Seybold 2008). The beetle was hypothesised to have been introduced to California from southeastern Arizona on infested firewood (Coleman and Seybold 2011; Coleman et al. 2012b). The movement of infested firewood within California has also likely led to satellite infestations elsewhere in San Diego County as well as in Riverside County (Idyllwild) (Coleman et al. 2012a; Jones et al. 2013). T. W. Coleman, United States Department of Agriculture Forest Service-Forest Health Protection, 602S. Tippecanoe Ave., San Bernardino, California 92408, United States of America M.I. Jones, Department of Entomology, University of California, Davis, California 95616, United States of America; and Department of Environmental and Forest Biology, State University of New York, 105 Illick Hall, 1 Forestry Dr. Syracuse, New York 13210, United States of America M.S. Hoddle, Department of Entomology, University of California, Riverside, California 92521, United States of America L.J. Haavik, Department of Entomology, University of California, Davis, California 95616, United States of America; and Natural Resources Canada – Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste. Marie, Ontario, Canada P6A 2E5 J.C. Moser, United States Department of Agriculture Forest Service, Southern Research Station (Emeritus), Pineville, Louisiana 71360, United States of America M.L. Flint, Department of Entomology, University of California, Davis, California 95616, United States of America S.J. Seybold, United States Department of Agriculture Forest Service, Pacific Southwest Research Station, Chemical Ecology of Forest Insects, Davis, California 95616, United States of America Corresponding author (e-mail: twcoleman@fs.fed.us). Subject editor: Justin Schmidt doi:10.4039/tce.2014.38 Received 16 January 2014. Accepted 14 March 2014. First published online 1 July 2014. Can. Entomol. 147: 244–248 (2015) © 2014 Entomological Society of Canada and Her Majesty the Queen in Right of Canada, as represented by the Minister of Natural Resources in Canada, 2014. Parts of this work were produced by U.S. Government employees and such parts are therefore not subject to copyright protection in the US. 244