Butterfly Farming Entomology Monarch (Danaus plexippus) Queen (Danaus gilippus)

Understanding O.E.: The Parasite Affecting Monarch Butterflies and How to Test for It

Ophryocystis elektroscirrha (O.E.) spores are much smaller than Monarch butterfly scales. The size of O.E. spores is typically in the range of 4 to 6 micrometers (µm) in length, which is about 0.005mm or 0.0002 inches, or one hundred times smaller than the butterfly’s scales.

A photo of a heavily infected Monarch Butterfly at 40X magnification, as might be used at school or home. Larger, apple seed/light bulb/corn kernel-shaped objects are butterfly scales. Inset is 400X view of O.E. spores, which are football-shaped.

Materials Needed

  • A clear sticker or transparent tape
  • Microscope slides
  • Microscope
  • Gloves
  • Forceps or tweezers

Steps for Gathering Samples

  1. Put on Gloves: Always wear gloves to minimize the risk of contaminating the sample or spreading the parasite.
  2. Capture the Butterfly: Gently capture the Monarch butterfly you wish to test. Handle it carefully to avoid causing it stress or harm.
  3. Apply the Sticker: Gently press a clear sticker or a piece of transparent tape against the butterfly’s abdomen, ensuring you’ve made contact with the scales.
  4. Remove and Place on Slide: Carefully peel off the sticker and place it onto a microscope slide.

Examining Under a Microscope

  1. Slide Preparation: Place the slide under the microscope, adjusting the focus until the sample is clear.
  2. Identification: Look for oval-shaped spores that are characteristic of O.E. They are usually quite distinct and easy to spot. There are very small, and require 400X magnification to see clearly. Butterfly scales are much larger than O.E. spores, but are also oval, so they can be mistaken for O.E. spores.
  3. Level of Infection: If you observe a high number of spores, the butterfly is likely heavily infected. A few spores indicate a lower level of infection.
  4. Record Findings: Make a note of your observations for future reference or for sharing with researchers.
Taken by Rob Wood with a Canon 80D DSLR through a Richter Optica HS-3 Biological microscope, at 400X. The large objects are scales, while the football-shaped objects are OE spores. Each spore contains 8 protozoa.

Conclusion

O.E. is a significant concern for Monarch and Queen butterflies, affecting their health, longevity, and even the broader ecosystem. While researchers continue to study this parasite, citizen scientists can also play a role. By understanding how to test for O.E., we can better gauge its prevalence and potentially help in conservation efforts… one day at a time!

Davis, A. K., Altizer, S., & Friedle, E. (2004). A Non-Destructive, Automated Method of Counting Spores of Ophryocystis elektroscirrha (Neogregarinorida: Ophryocystidae) in Infected Monarch Butterflies (Lepidoptera: Nymphalidae). The Florida Entomologist, 87(2), 231–234. http://www.jstor.org/stable/3496931

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