Monarch Butterfly

Monarch OE (Ophryocystis elektroscirrha) is a protozoan parasite that infects monarch butterflies (Danaus plexippus). It is transmitted mainly by spores shed by infected adult monarchs. The spores contaminate milkweed plants which monarch caterpillars consume & continue the cycle. Infected adult monarch butterflies have a reduced lifespan, deformed wings which impair flight and decreased reproductive success.

O.E. spores are typically found on the Monarch butterfly’s abdomen. They measure roughly 10µm & require a visual aid such as a microscope to be seen although a trained eye may be able to use a simple 15X pocket loupe. If more power is needed, a 10X hand lens together with a cell phone can act as a portable dissecting microscope with 50X or more.

Captive breeders of Monarch butterflies need to confidently raise OE-free monarchs by knowing you have the correct bleach ratio in ppm each time you disinfect your milkweed or rearing containers. This mixture will eradicate not only OE but also tachinid flies, NPV (Nuclear Polyhedrosis Virus) & Pseudomonas sp. bacteria.