Parasites & Natural Enemies
Background and Life Cycle of Ophryocystis elektroscirrha
Introduction | Background on Ophryocystis elektroscirrha | Research Projects
Ophryocystis elektroscirrha is a protozoan parasite that was first recovered from monarch and queen butterflies in Florida in 1966 (McLaughlin and Myers 1970). New infections occur when larvae ingest parasite spores as they feed on contaminated egg shells or milkweed leaves. Most spores are transmitted from infected adults to their offspring (vertical transmission), although horizontal transmission may also occur. Following ingestion, spores lyse in larval guts. Emerging sporozoites then penetrate the intestinal wall, enter the hypoderm, and undergo two phases of vegetative, asexual replication. After host pupation, the parasite undergoes sexual reproduction and forms dormant spores around the scales of the developing adult butterfly (McLaughlin and Myers 1970). Most spores form on the adult abdomen, although spores also develop on the wings, head, and thorax (Leong et. al. 1992; S.M. Altizer, personal observation).
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| Life Cycle of O. elektroscirrha |
Heavily infected adults have difficulty emerging from their pupal cases and expanding their wings, although adults with low parasite loads appear normal (McLaughlin and Myers 1970; Leong et al. 1992). High parasite doses decrease larval survivorship from hatching to eclosion, and heavily captive adults are smaller and shorter-lived than uninfected adults (Altizer and Oberhauser 1999).
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| Clusters of O. electroscirrha spores form dark blotches under the cuticle of developing pupae (L) about 3 days before eclosion. A monarch dissected out of its pupal case (R) shows that most spores form in the abdomen of infected butterflies. |
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| Heavily infected captive monarchs (L) often are too weak to emerge from their pupal cases or expand their wings. Spores of O. electroscirrha (R) appear as small brown ovals next to the larger butterfly scales. |
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References
Alonso-Mejia A. Brower L.P. 1994. From model to mimic: Age-dependent unpalatability in monarch butterflies. Experientia (Basel) 50(2). 176-181.
Altizer, S. and Oberhauser, K. 1999. Effects of the protozoan parasite, Ophryocystis elektroscirrha, on the fitness of monarch butterflies (Danaus plexippus). Journal of Invertebrate Pathology. In press.
Bowers, R.G, Begon, M. and Hodgkinson, D.E. 1993. Host-pathogen population cycles in forest insects? Lessons from simple models reconsidered. Oikos 67(3) 529-538.
Brewer, J. and Thomas, G.M. 1966. Causes of death encountered during rearing of Danaus plexippus (Danaidae). Journal of the Lepidopterists' Society. 20(4). 235-238.
Brower, L. 1988. Avian predation on the monarch butterfly and its implications for mimicry theory. American Naturalist 131. S4-S6.
Brower, L.P. Calvert W.H. 1985. Foraging dynamics of bird predators on overwintering monarch butterflies Danaus plexippus in Mexico. Evolution 39(4). 852-868.
Brower L.P. Seiber J.N. Nelson C.J. Lynch S.P. Holland M.M. 1984. Plant-determined variation in the cardenolide content, thin-layer chromatography profiles, and emetic potency of monarch butterflies, Danaus plexippus reared on milkweed plants in California (USA): 2. Asclepias speciosa. Journal of Chemical Ecology 10(4). 601-640.
Calvert, W.H. 1996. Fire ant predation on monarch larvae (Nymphalidae: Danainae) in a central Texas prairie. Journal of the Lepidopterists' Society. 50(2) 149-151.
Faeth, S.H. and Simberloff, D. 1981. Population regulation of a new leafmining insect, Cameraria sp., at increased field densities. Ecology 62(3): 620-624.
Fink, L.S. and Brower L.P. 1981. Birds can overcome the cardenolide defense of monarch butterflies (Danaus plexippus) in Mexico. Nature 291(5810). 67-70.
Frick C. Wink M. 1995. Uptake and sequestration of ouabain and other cardiac glycosides in Danaus plexippus (Lepidoptera: Danaidae): Evidence for a carrier-mediated process. Journal of Chemical Ecology 21(5). 557-575.
Jaenike, J. 1998. On the capacity of macroparasites to control insect populations. American Naturalist 151(1) 84-96.
Leong KLH. Kaya H.K. Yoshimura M.A. Frey D.F. 1992. The occurrence and effect of a protozoan parasite Ophryocystis elektroscirrha (Neogregarinida: Ophryocystidae) on overwintering monarch butterflies Danaus plexippus (Lepidoptera: Danaidae) from two California winter sites. Ecological Entomology 17(4). 338-342.
Leong KLH. Yoshimura M.A. Kaya H.K. and Williams, H. 1997. Instar susceptibility of the monarch butterfly (Danaus plexippus) to the neogregarine parasite, Ophryocystis elektroscirrha. Journal of Invertebrate Pathology. 69(1) 79-83.
McLaughlin, R.E. and Myers, J. 1970. Ophryocystis elektroscirrha sp. n. a neogregarine pathogen of the monarch butterfly Danaus plexippus (L.) and the Florida quen butterfly Danaus gilippus berenice Cramer. Journal of Protozoology. 17. 300-305.
Ritland, D.B. Brower L.P. 1993. A reassessment of the mimicry relationsihp among viceroys queens and monarchs in Florida. Natural History Museum of Los Angeles County Science Series (38). 129-139.
Sakai, W.H. 1994. Avian predation on the monarch butterfly, Danaus plexippus (Nymphalidae: Danainae), at a California overwintering site. Journal of the Lepidopterists' Society 48(2). 148-156.
Urquhart, F.A. 1987. The Monarch Butterfly: International Traveler. Nelson-Hall, Chicago, IL. 232 pp.
Zalucki, M.P. Brower, L.P. Malcolm, S.B. 1990. Oviposition by Danaus plexippus in relation to cardenolide content of three Asclepias species in the Southeastern USA. Ecological Entomology 15(2). 231-240.
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