New records and species of Tetranychidae and Tenuipalpidae (Acarina) from Utah and Idaho

Abstract

Twenty-three species of spider mites (Tetranychidae) are recognized for Utah and Idaho; three of these are described as new: Br y obi a ne or i bis, Pseudobryobia knowltoni , and Schizotetranychus agropyron. Eleven species of Tenuipalpidae are recorded. Spider mites and false spider mites are relatively well known in only a few regions of the United States such as Arizona and California where economic and native plants have been carefully surveyed. Therefore, it was believed opportune to publish the following records of tetranychoid mites from Utah and Idaho. These records were compiled from numerous collections made by George F. Knowlton, Professor Emeritus of Entomology at Utah State University, 1972-1975. Information on species other than these was taken from Pritchard and Baker (1955 and 1958) and Knowlton and Ma (1950). A total of 24 species of Tetranychidae were determined; Bryobia neoribis , Pseudobryobia knowltoni , and Schizotetranychus agropyron are described as new. Eleven species of Tenuipalpidae were recorded. Tetranychidae Donnadieu, 1875 Bryobia praetiosa Koch Bryobia praetiosa Koch, 1836:8; Pritchard and Baker, 1955:26; Wainstein, 1960:102; Tuttle and Baker, 1968:6. The clover mite (B. praetiosa) is one of the most common species and occurred as follows: Aesculus hippocastanum L. (horse chesnut) ex duff, Logan, Utah, 15 Apr 1973 and 2 May 1974; Agropyron desertorum (Fisch.) Schult. (crested wheatgrass), Duck Creek Camp (Kane Co.), Utah, 5 May 1973 and Holbrook, Idaho, 19 Oct 1972; Agropyron smithii Rydb. (western wheatgrass), Reese Valley (Chicken Creek Canyon), Utah (7,500 ft.), 19 May 1972; Artemisia nova A. Neis., Logan Canyon, Utah, 2 Jul 1973; Artemisia tridentata Nutt. (big sagebrush) ex duff, Logan, Utah, 14 Nov 1972; Chrysanthemum sp., Logan, Utah, 24 Oct 1973; Chrysothamnus nauseosus (Pall.) Britton (rabbitbrush), Logan Canyon, Utah, 5 Jun 1973 and Paradise, Utah, 6 Jun 1973; Chrysothamnus sp. ex duff, Snowville, Utah, 15 Nov 1972 and North Logan, Utah, 14 Nov 1972; grasses (not determined), 10 collections (some include duff) from Idaho and Utah, Feb-May 1973; Juniperus sp. ex duff, Black Pine Mt. (Curlew Valley), Idaho, 3 May 1974 and Juniper, Idaho, 15 Nov 1972; moss, Blacksmith Fork Canyon, Utah, 30 Apr and 2 May 1973; Ribes inerme Rydb. (gooseberry), Tony Grove Canyon (Cache Co.), Utah, 30 Jul 1974; and Sarcobatus vermiculatus Torr, (greasewood) ex detritus, Wildcat Hills (Box Elder Co.), Utah, 18 Apr 1974. It was reported by Knowlton and Ma (1950) in Utah on alfalfa, sweetclover, and rabbitbrush. Bryobia rubrioculus (Scheuten) Sannio rubrioculus Scheuten, 1857:104. Bryobia rubrioculus : Tuttle and Baker, 1968:7. Collections were made from Juniperus sp. ex duff, Black Pine (Oneida Co.), Idaho, 3 May 1973; Lonicera sp. (honeysuckle), Hyde Park, Utah, 16 May 1972; Populus tremuloides Michx. ex duff, Monte Cristo, Utah, 21 Jun 1973; Salix sp. ex duff, Mantua, Utah, 17 May 1973; and Sarcobatus vermiculatus Torr, (greasewood) ex duff, Wildcat Hills (Box Elder Co.), Utah, 18 Apr 1974. Bryobia neoribis , n. sp. Figs. 1-7 This species is related to Bryobia ribis Thomas, a European species, but differs in having more slender body setae, in having the inner coxal I seta about twice as long as the outer serrate seta, in having Agricultural Experiment Station, University of Arizona, Yuma Branch Station. Systematic Entomology Laboratory, IIBIII, Agr. Res. Serv., USDA, Beltsville, Maryland 20705.