Isoplastus fossor Horn, 1880: 295 Brown 1937b: 174 Daffner 1988: 302 Daffner 1988: 302 Isoplastus uncus Wheeler, 1977: 77 Daffner 1988: 302 Systematics and distributions of the genera Cyrtusa Erichson, Ecarinosphaerula Hatch, Isoplastus Horn, Liocyrtusa Daffner, Lionothus Brown, and Zeadolopus Broun of the United States and Canada (Coleoptera: Leiodidae: Leiodinae: Leiodini) Peck, Stewart B. Cook, Joyce Insecta Mundi 2013 2013-06-28 2013 310 1 32 6MZMM Horn, 1880 Horn 1880 [192,576,1249,1274] Insecta Leiodidae Isoplastus Animalia Coleoptera 8 7 Arthropoda species fossor  ( Fig. 2, 17)      Isoplastus fossor Horn, 1880: 295;  Brown 1937b: 174;  Daffner 1988: 302. Lectotypemale in MCZC, type number 3191, seen; designated by  Daffner 1988: 302. Type locality: District of Columbia.     Isoplastus uncus Wheeler, 1977: 77;  Daffner 1988: 302, synonymy.  Typemale in MCZC, type number 32322, seen. Type locality: Fortin de las Flores, Veracruz, Mexico.   Diagnosis.Length (pronotum + elytra) = 1.18–2.00 mm; greatest width = 0.78–1.39 mm. Reddish brown, shiny. Head finely, sparsely punctate. Antennomere 2 clearly longer and broader than 3; antennomere 7 thin, about half width of 8; apical antennomere distinctly narrower than 9. Sides of pronotum rounded, posterior angles obtuse. Pronotum finely, sparsely punctate. Elytral strial punctures coarse, finer anteriorly, separated by one diameter or less, except anteriorly; interstrial punctures minute, sparse. Metasternum strongly, densely punctate. Legs as in generic diagnosis. Abdominal sternites III–VIII each with transverse row of small punctures on apical half; sternite III rugose. Median lobe of aedeagus ( Fig. 2) broad, angled about 90 degrees in lateral view; paired apices each divided at tip. Parameres ( Fig. 2) extend beyond apex of median lobe. Armature of inverted internal sac as in Fig. 2.   Distribution.North American distribution ( Fig. 17):  CANADA. ONTARIO, QUEBEC.  UNITED STATES. ALABAMA, ARKANSAS, ARIZONA, DISTRICT OF COLUMBIA, FLORIDA, GEORGIA, INDIANA, KENTUCKY, LOUISIANA, MICHIGAN, MISSISSIPPI, NORTH CAROLINA, OKLAHOMA, SOUTH CAROLINA, TEXAS, VIRGINIA. Extra-limital distribution: Mexico(doubtful, see Remarks). Previously recorded in North America ( Horn 1880, Brown 1937b, Daffner 1988) from:  CANADA. ONTARIO. Arnprior. QUEBEC. Aylmer.  UNITED STATES. MICHIGAN. Detroit. DISTRICT OF COLUMBIA.  Seasonality.Adults have been collected from February to November, and mostly in June to August, with the early and late season records from southerly locations in Floridaand Texas.  Bionomics.Adults have been collected in habitats ranging from open pine forest and juniper thicket to mature mixed and bottomland beech-magnolia forest. Taken mostly by flight intercept traps but also by sweeping and ultraviolet light traps.   Remarks. We question the above synonymy and think it needs re-examination. We suspect that  I. uncusis actually a valid species, and we have seen several undescribed species of  Isoplastusfrom Mexicoand southward.  New material examined.We have seen 434 specimensfrom the following localities.  CANADA. ONTARIO. L3C6 Wolford Township, 44° 52’03”N, 75°43’50” W. Tilbury.  UNITED STATES. ALABAMA. Dale Co.Ft. Rucker Military Reservation. Jefferson Co., Hoover. ARKANSAS. Little Rock Co., Little Rock. Logan Co., Magazine Mountain. ARIZONA. Cochise Co., Chiricahua Mts., Turkey Creek. FLORIDA. Alachua Co., Gainesville. 10 kmSW Gainesville. Jackson Co., Marianna, Florida Caverns State Park. Sneads, Three Rivers State Park. Leon Co., 20 miN Tallahassee, Tall Timbers Station. Liberty Co. 14 kmN Bristol, Appalachicola Bluffs and Ravines Preserve. Suwanee Co., Suwanee River State Park. GEORGIA. Greene Co., Oconee National Forest. INDIANA. Tippecanoe Co. KENTUCKY. Edmonson Co., Mammoth Cave National Park. Metcalfe Co., 0.5 miNE East Fork. LOUISIANA. Catahoula Parish, Walters, Catahoula National Wildlife Refuge. Grant Parish, 18 kmN Alexandria, Stuart Lake Camp. Natchitoches Parish, Kisahatchie Bayou. West Feliciana Parish, Feliciana Preserve. MISSISSIPPI. Pontotoc Co., 32 kmSW Tupelo, Tockshish. NORTH CAROLINA. Northampton Co., 7 kmS Jackson. OKLAHOMA. Latimer Co., Red Oak. Wagoner Co., 3 miW Wagoner. SOUTH CAROLINA Anderson Co., Pendleton. Oconee Co., 12 miNE Walhalla. Pickens Co., Calhoun. TEXAS. Bell Co., 1 kmW Youngsport. Brazos Co., Lick Creek Park, College Station. Ellis Co., 3.6 miNW Italy. Hays Co., 6 miNW Dripping Springs. 6.5 miSW Hunt. Kerr Co., Kerrville. Montgomery Co., 4.5 miN Montgomery. Polk Co., 20 kmS Coldspring. Sabine Co., 9 miE Hemphill, Beech Bottom. San Augustine Co., Piney Woods Conservation Center. San Jacinto Co., 5 kmS Coldspring. Shelby Co., 20 kmSE Shelby. Tyler Co., 5 miE Spurger. Wood. Co., Godwin Woods, 3.5 miSW Hainesville. VIRGINIA. Fredericksburg. Warren Co., 4 kmNNW Linden. 4400754301 MCZC Mexico Fortin de las Flores Flores 8 7 32322 1 Veracruz type