The first sign that what you were told isn’t true is Monarch butterfly migration. Monarch butterflies migrate in the spring from Mexico. They ARE coming from over 100 miles away to begin with! BUT – that being said, read on. Disease is a serious matter and you are wise to ask questions.
Ophryocystis elektroscirrha (OE)
is a protozoan disease that affects butterflies that use milkweed as a host plant. It infects many Monarchs all over the US in varying degrees. In the tip of Florida, about 85% of Monarchs have OE. In the eastern side of the US, 30% – 35% are infected with OE. In the western half of the US (west of the divide), about 2% – 3% are infected with OE.
OE is natural – even with an 85% infection rate, the southern tip of Florida has Monarchs flying year round. With an 85% infection rate, the Monarch butterfly population does not seem to be in danger in south Florida. But many Monarch butterflies die from OE; not a happy thought.
The reason the infection rate is so high in the tip of Florida is simple. First, there are Monarch and Queen butterflies year round in south Florida and second, the plants never freeze to the ground which means that spores are always present for caterpillars to eat. The cycle simply doesn’t have a rest. Further north, milkweed freezes to the ground, disintegrates, and spores wash into the soil. Monarch butterflies are not present with a large population year round. When fresh leaves grow in the spring in the north, new caterpillars are eating fresh leaves that few Monarchs have touched. Thus – fewer spores = fewer Monarchs with disease. But earlier in the spring, fewer butterflies in the wild are infected with OE. Later in the year, more are infected with OE.
Teachers often have big problems with OE when they bring in wild caterpillars. The caterpillar contracts the disease when it eats a spore – and the spore can be on the eggshell. Over 100 spores fit on one wing scale. When a caterpillar is brought in from the wild that has already eaten one or more OE spores, the butterfly already has the disease.
As Monarch butterflies fly around and land on milkweed plants, these spores fall onto the leaves. As caterpillars eat the leaves, they contract the disease.
When a female lays an egg, she may leave one or several scales on the eggshell. When the hatching caterpillar eats its eggshell, it may be eating from one to hundreds of spores.
Atlanta and OE; there is OE in Atlanta. If you go outside and catch a wild Monarch, there is a good chance it will have OE. Not as great a chance as someone further south of you bringing in a wild Monarch butterfly!
Our farm offers a free OE check for those who have problems with their caterpillars and butterflies. At times the scales that are mailed to us are covered with OE spores – even from New York or Michigan. The information sharing how to send some scales (it doesn’t harm the butterfly) is at the bottom of our OE page linked above.
is a bad Monarch butterfly disease
but it is ever present in nature. Many, if not most, butterfly farmers take OE serious. Using careful prevention and rearing techniques, their Monarch butterflies do not have OE. OE and other disease prevention is a basic part of our butterfly farm seminar and internship program
If you are buying Monarch butterflies for a butterfly release
in your area, ask the butterfly farmer questions about his/her butterfly rearing operation in reference to disease. Does he/she check the breeding stock for OE? Are the Monarch eggs washed with a disinfectant? Are the milkweed plants grown inside a greenhouse or screen house where wild butterflies cannot get to them to leave spores? If their plants are grown outdoors, are the leaves washed with a disinfectant before they are fed to butterfly caterpillars / larvae? If the farmer takes offense at your questions – I would wonder why. Disease is serious!
If you bring in Monarchs from the house next door to your house in Atlanta, there is a good chance you will bring in OE. The distance you bring them from doesn’t have anything to do with whether you bring in disease into your region of the US. When you’re buying Monarch butterflies, whether the butterflies have disease depends upon the care a farmer uses when raising his/her Monarch butterflies and with their milkweed, not with the distance they originated from your home.
Some diseases are inside the egg – the baby is born with the disease and nothing can be done. Luckily OE isn’t one of them! It HAS to be eaten for the caterpillar to contract the disease. When a butterfly breeder's rearing operation is focused on disease prevention, you eliminate OE from their butterflies.
On the webpage linked above, we share how we raise OE free Monarchs and help others to do the same, whether as a hobby, a teacher, or whatever. We wash our Monarch eggs with a bleach solution so that when the hatchling caterpillar eats its egg shell, it will be clean of any disease pathogens, including OE. We grow all our milkweed plants inside greenhouses (six of them) so wild Monarch and Queen butterflies cannot get to the plants to leave spores for our caterpillars to eat. (All university rearing operations that I am familiar with, raising moth and/or butterfly, wash their eggs in a disinfectant solution to kill all disease pathogens.)
The short answer to you question is that it doesn’t matter where they are coming from but how they are raised!
A microscope is used to
check butterflies for disease.
Monarch Butterfly cannot emerge
from its chrysalise due
to disease; OE
OE spores in a disinfectant
bleach solution kills