Summary about Disease
Ophryocystis elektroscirrha (OE) is a protozoan parasite that infects monarch and queen butterflies. It primarily affects the larval and pupal stages, but the effects are most visible in adult butterflies. Infected butterflies often have difficulty emerging from their chrysalis and may exhibit deformities. The parasite reduces flight ability, lifespan, and reproductive success.
Symptoms
Adult butterflies may have:
Small size
Pale color
Deformed wings (misshapen, tattered, or with missing scales)
Distended abdomens (due to a high parasite load)
Inability to fly or fly weakly
Reduced lifespan
Failure to emerge completely from the chrysalis
Infected larvae and pupae may appear normal externally but carry the parasite.
Causes
Infection occurs when monarch or queen butterfly larvae ingest OE spores present on milkweed plants. These spores are shed by infected adult butterflies as they lay eggs. Transmission can also occur from the mother butterfly to her eggs (vertical transmission).
Medicine Used
There is no direct "medicine" or drug treatment for OE infection in monarch butterflies in the wild. Management focuses on preventing transmission through habitat management and selective breeding in captive populations.
Is Communicable
Yes, OE is highly communicable among monarch and queen butterflies. Transmission occurs primarily through the ingestion of spores shed by infected adults onto milkweed, and from mother to offspring.
Precautions
Habitat Management: Regularly mow or cut back milkweed to remove older leaves that may be heavily contaminated with OE spores. Consider planting new milkweed patches each year.
Raising Monarchs in Captivity (if applicable):
Use healthy monarchs as breeding stock.
Disinfect enclosures and equipment regularly with a bleach solution (diluted bleach).
Provide fresh, clean milkweed daily.
Isolate and test suspect individuals.
Release only healthy butterflies.
Citizen Science: Participate in monitoring programs that track OE prevalence in wild monarch populations.
How long does an outbreak last?
OE is a persistent issue, not an outbreak in the typical sense of a short-lived disease event. Prevalence fluctuates seasonally and geographically. It can be a constant threat to monarch populations in areas with high spore loads on milkweed. The impact is more pronounced during generations that are more reliant on existing milkweed patches versus newly emerging growth.
How is it diagnosed?
OE is diagnosed by microscopic examination of the scales from the abdomen of adult butterflies. The scales are collected using clear tape, placed on a microscope slide, and examined for the presence of OE spores.
Timeline of Symptoms
Larval Stage: Larvae ingest spores, but symptoms are not usually visible.
Pupal Stage: The parasite replicates rapidly. Deformities and other effects start developing inside the chrysalis.
Adult Stage: Symptoms are most apparent upon emergence. Severely infected butterflies may fail to emerge. Those that do emerge exhibit deformities, reduced flight ability, and shortened lifespans.
Overall: The impact of the infection intensifies as the butterfly develops through each stage.
Important Considerations
OE is a significant stressor on monarch populations, especially those already threatened by habitat loss and other environmental factors.
Efforts to reduce OE prevalence are crucial for monarch conservation.
Citizen scientists and butterfly enthusiasts can play a valuable role in monitoring OE and implementing preventative measures.
It is important to differentiate OE symptoms from other possible causes of butterfly deformities or weakness.