Monarch OE Check Without a Microscope

“Can I check a Monarch for OE without a microscope?”

You can, but the check will show ONLY if the Monarch (or Queen) butterfly is heavily infected with OE spores. If the butterfly is medium to lightly infected with OE, this test is of no value. Spores will not be visible. The only reason this works is that the massive number of spores (thousands) on the glass is enough to darken a spot on the glass. The human eye cannot see individual spores.

If a butterfly is crippled from OE, it will have enough spores on it for this test to work.  Again, light to medium infected butterflies cannot be tested this way.  It requires a microscope to see spores for those butterflies.

The below image is two images merged together.  Both images are of the same slide.  The top slide has tape on it.  The bottom slide has the tape removed.  The dark spots on the bottom slide are thousands and thousands of OE spores without scales.

Check a Monarch butterfly for heavy OE without a microscope
Check a Monarch butterfly for heavy OE without a microscope

Tools needed:
~ Butterfly
~ Tape
~ Clear glass (drinking glass, saucer, or any CLEAR piece of glass)
~ Bright light or window

(Before you begin, if the glass is something you do not intend to keep, draw a circle the size of a dime on the glass. The only reason for the circle is to help you locate the exact spot on the glass where you had pressed the scales once you remove the tape.)

Four simple steps:
1. Firmly press the tape to the abdomen of the butterfly. Be gentle but firm. A good number of scales should be removed from the abdomen. This doesn’t harm the butterfly. The images to the left give a good indication of the number of scales that should be on the tape.
2. In the middle of the circle, firmly press the scales part of the tape against the glass. Rub your finger firmly over the tape.
3. Remove the tape from the glass. Dispose of the tape in the garbage can.
4. Hold the glass up to the light or bright window and look at the area where the scales had been pressing against the glass. Important: you are looking at the glass WITHOUT the tape at this point.

If a dark smudge is seen where the scales were on the glass, the butterfly is heavily infected with OE.

During the last three days of the chrysalis stage of a Monarch or Queen’s life cycle, the OE parasite begins to create spores. It does this between the outer layers of the chrysalis. When the adult emerges, the spores are then on the outside ONLY of the butterfly. Inside the adult butterfly, it is OE free. Spores are not attached to the butterfly. Scales are attached by small scale stalks.

When tape is pressed to the butterfly’s abdomen, attached scales are pulled loose as well as OE spores that are loosely sitting on and between the scales. Scales stick to the tape. Spores that are on top of scales are trapped between the glass and scales when the tape is pressed against the glass. When the tape is removed, many of those spores will stay on the glass. This is the dark smudge that is left on the glass.

If enough spores are on the glass to create a dark smudge, the butterfly was very heavily infected with OE. It has a huge number of spores on its body.

(It does not harm a butterfly for scales to be removed. This is part of a natural part of the adult life of a butterfly. Scales are constantly falling from butterflies as they fly, mate, and live a normal life.)

If a freshly emerged Monarch has blurry or smudged appearing white patches on its abdomen, it often means it has many OE spores on its abdomen. The spores are covering the white scales enough to make them appear somewhat out of focus. Without the spores, the white scales are crispy white in appearance. A wild caught butterfly or older butterfly may be totally OE free and have blurry white patches simply from losing white scales from the bumps of life. Crispy white patches of scales should be expected only on freshly emerged Monarch butterflies.