Date: 08/04/2012

Number: 1

The monarch butterflies migrated in early May to Northern Wisconsin 3-4 weeks ahead of schedule and in record numbers. The milkweed that had broken ground was only a couple of inches tall. The monarchs layed hundred of eggs. The 1st week of June we had heavy frost followed by high winds. The caterpillars that survived were 5th instars and many were in transition. There was a higher than usual mortality rate in all stages. I had approximately 120 chrysalises in June which is about half of what I have observed previous years in July. The temperature later in June climbed well into the 90's. Approximately 20% of the chrysalises dried out. Many of the caterpillars were darker than usual. I have observed more defined black lines in the caterpillars in September, but not during the Spring/Summer months.
Numbers of July and August eggs and caterpillars are way down. The monarch season seems to be out of sync in Wisconsin.
I have been involved in a monarch butterfly project for 13 years and have not experience this.

Arbor Vitae, WI

Latitude: 45.9 Longitude: -89.7

Observed by: Patricia
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