Snyder, S. D., and R. E. Clopton. 2005. New Methods for the Collection and Preservation of Spirorchiid and Polystomatid Trematodes from Turtles. Comparative Parasitology 72: 102-105.

Hays, J., R. E. Clopton, D. L. Cappaert, and D. R. Smitley. 2004. Revision of the genus Stictospora and description of Stictospora villani, n. sp. (Apicomplexa: Eugregarinida: Actinocephalidae) from the Japanese beetle Popillia japonica (Coleoptera: Scarabaeidae) in Michigan, USA. Journal of Parasitology 90:1450-1456.

Clopton, R. E. 2004. Standard nomenclature and metrics of plane shapes for use in gregarine taxonomy. Comparative Parasitology 71: 130-140.   

Clopton, R. E. 2004. Calyxocephalus karyopera g. nov., sp. nov. (Eugregarinorida: Actinocephalidae: Actinocephalinae) from the ebony jewelwing damselfly Calopteryx maculata (Zygoptera: Calopterygidae) in southeast Nebraska: implications for mechanical prey-vector stabilization of exogenous gregarine development. Comparative Parasitology 71: 141-153.

Clopton, R. E., T. J. Cook, and J. L. Cook.  2004. Naiadocystis phykoterion n. gen., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae) from the mexican pygmy grasshopper Paratettix mexicanus (Orthoptera: Tetrigidae) in the Texas Big Thicket with recognition of three previously described species of Naiadocystis. Journal of Parasitology 90: 301-307.   

Smith A., and R. E. Clopton. 2003.  Efficacy of oral metronidazole and potassium sorbate against two gregarine parasites, Protomagalhaensia granulosae and Gregarina cubensis (Apicomplexa: Eugregarinida) infecting the Death’s Head Cockroach, Blaberus discoidalis. Comparative Parasitology 70: 196-199.

Leander, B. S., R. E. Clopton, and P. J. Keeling.  2003. Phylogeny of gregarines (Apicomplexa) as inferred from small-subunit rDNA and beta-tubulin. International Journal of Systematic and Evolutionary Microbiology 55: 345-354.

Clopton, R. E., and C. M. Nolte. 2002. Clitellocephalus americanus n. gen., n. sp. (Apicomplexa: Eugregarinida: Gregarinidae) from Cratacanthus dubius (Coleoptera: Carabidae: Harpalinae) in the Nebraska Sandhills and Clitellocephalus ophoni n. comb. (Apicomplexa: Eugregarinida: Gregarinidae) from Ophonus pubescens (Coleoptera: Carabidae: Harpalinae) in Sète, France. Journal of Parasitology 88: 750-757.

Clopton, R. E., and A. Smith.  2002. Efficacy of oral sulfadimethoxine against two gregarine parasites, Protomagalhaensia granulosae and Gregarina cubensis (Apicomplexa: Eugregarinida) infecting the Death’s Head Cockroach, Blaberus discoidalis. Journal of Parasitology 88: 786-789.

Clopton, R. E. 2002.  Phylum Apicomplexa Levine, 1970: Order Eugregarinorida Léger, 1900. Pages 205-288 in:  Illustrated Guide to the Protozoa, 2^nd edition, J. J. Lee, G. Leedale, D. Patterson, and P. C. Bradbury, eds.  Society of Protozoologists, Lawrence, Kansas.

Cook, T. J., J. Janovy, Jr., and R. E. Clopton.  2001. Epimerite-host epithelium relationships among eugregarines parasitizing the damselflies Enallagma civile and Ischnura verticalis.  Journal of Parasitology 87: 988-996.

Clopton, R. E. 2000.  Stylocephalus occidentalis n. sp.(Apicomplexa: Eugregarinida: Stylocephalidae) from Trimytis pruinosa (Coleoptera: Tenebrionidae) in the Nebraska Sandhills. Journal of Parasitology 86: 560-565.

Clopton, R. E., and R. R. Kula.  1999. Amoebogregarina nigra n. gen., n. comb. (Apicomplexa: Gregarinidae) From Adult Melanoplus differentialis (Orthoptera: Acrididae) in Southeastern Nebraska. Journal of Parasitology 85: 321-325.

Clopton, R. E. 1999.  Revision of the genus Xiphocephalus and description of Xiphocephalus ellisi n. sp.(Apicomplexa: Eugregarinida: Stylocephalidae) from Eleodes opacus (Coleoptera: Tenebrionidae) in the western Nebraska Sandhills.  Journal of Parasitology 85:84-89.

Lucarotti, C. J., T. L. Leclerc, and Clopton, R. E.  1998. Incidence of Leidyana canadensis (Apicomplexa: Eugregarinida) in Lambdina fiscellaria fiscellaria larvae (Lepidoptoera: Geometridae).  Canadian Entomologist 130: 583-594.

Clopton, R. E. 1998.  Revision of the genus Torogregarina and description of Torogregarina sphinx n. Sp. (Apicomplexa: Eugregarinida) from a Missouri river bank beetle, Bembidion laevigatum (Coleoptera: Carabidae), in southeastern Nebraska. Journal of Parasitology 84: 823-827.

Clopton, R. E. and C. J. Lucarotti.  1997. Leidyana canadensis N. Sp. (Apicomplexa: Eugregarinida) from larval Eastern Hemlock Looper, Lambdina fiscellaria fiscellaria (Lepidoptoera: Geometridae). Journal of Eukaryotic Microbiology 44: 383-387.

Janovy, Jr., S. D. Snyder, and R. E. Clopton.  1997. Evolutionary constraints on population structure: the parasites of Fundulus zebrinus (Pisces: Cyrinodontidae) in the South Platte River of Nebraska. Journal of Parasitology 83: 584-592.

Clopton, R. E. 1995.  Leidyana migrator n. sp. (Apicomplexa: Leidyanidae) from the Madagacar hissing cockroach, Gromphadorhina portentosa (Insecta: Blattodea).  Invertebrate Biology 114: 271-278.

Clopton, R. E. and R. E. Gold. 1996.  Host Specificity of Gregarina blattarum among Five Species of Domiciliary Cockroaches. Journal of Invertebrate Pathology 67: 219-223.

Clopton, R. E. 1995.  Domadracunculus janovyii n. gen., n. sp., (Apicomplexa: Actinocephalidae) described from adults of Ischnura verticalis (Odonata: Zygoptera) in Texas. Journal of Parasitology 81:256--260.

Clopton, R. E. and R. E. Gold. 1995.  Effects of pH on excystation in Gregarina cuneata and Gregarina polymorpha (Eugregarinida: Gregarinidae). Journal of Eukaryotic Microbiology  42: 540-544. 

Percival, T. J., R. E. Clopton and J. Janovy, Jr.  1995. Hoplorhynchus acanthatholius N. Sp. and Steganorhynchus dunwoodii N. Gen. N. Sp. (Apicomplexa: Eugregarinorida) described from Coenagrionid Damselflies.  Journal of Eukaryotic Microbiology 42: 406-410.

Janovy, Jr., R. E. Clopton, D. A. Clopton, S. Snyder, A. Efting and L. Krebs.  1994. Species density distributions as null models for ecologically significant interactions of parasite species in an assemblage. Ecological Modeling 77: 189-196.

Clopton, R. E. and R. E. Gold. 1993.  Distribution and Seasonal and diurnal activity patterns of Eutrombicula alfreddugesi (Acari: Trombiculidae) in a forest edge ecosystem. Journal of Medical Entomology 30: 47--53.

Clopton, R. E. and J. Janovy, Jr. 1993 Developmental niche structure in the gregarine assemblage parasitizing Tenebrio molitor. Journal of Parasitology 79:701--709.

Clopton R. E., T. J. Percival  and John Janovy, Jr.  1993. Nubenocephalus nebraskensis N. Gen., N. Sp. (Apicomplexa: Actinocephalidae) described from Argia bipunctulata (Odonata: Zygoptera). Journal of Parasitology 79: 533--537.

Ferdig, T.,  M. A. McDowell, R. E. Clopton and Janovy, J. Jr.  1993. Patterns of morphological variation of Salsuginus yutanensis (Monogenera: Ancyrocephalidae) over space and time. Journal of Parasitology 79: 744-750.

Clopton, R. E. and R. E. Gold. 1992. Bite-Count evaluation of the repellency of N,N-Diethyl-3-methylbenzamide to larval Eutrombicula alfreddugesi (Acari: Trombiculidae).  Journal of Medical Entomology 29: 858-863.

Clopton R. E., T. J. Percival and John Janovy, Jr. 1992. Host Stadium Specificity in the gregarine assemblage parasitizing Tenebrio molitor.  Journal of Parasitology 78: 334--337.

Clopton R. E., T. J. Percival and John Janovy, Jr. 1992.  Gregarina coronata N. Sp. (Apicomplexa: Eugregarinida) described from adults of the Southern Corn Rootworm, Diabrotica undecimpunctata howardi.  Journal of Protozoology 39: 417--420. 

Janovy, Jr., R. E. Clopton and T. J. Percival.   1992. The Roles of ecological and evolutionary influences in providing structure to parasite species assemblages.  Journal of Parasitology 78: 630-640.

Clopton R. E., T. J. Percival and John Janovy, Jr. 1991.  Gregarina niphandrodes N. Sp. (Apicomplexa: Eugregarinorida) from adult Tenebrio molitor (L.) with oocyst descriptions of other gregarine parasites of the Yellow Mealworm. Journal of Protozoology 38:472--483.

Clopton R. E.  1991. A review of the Scaritinid Beetles (Coleoptera: Carabidae) of Nebraska.  Transactions of the Nebraska Academy of Science 18: 53--65.