Monarch Migration Update (4/18/94)

Monarch Butterfly Migration Update
April 18, 1994

DATE # SEEN PLACE 4/7 1 Junction City, Kansas 4/7 1 Palmdale, California 4/7 5 Carrollton, Texas 4/8 4 Mableton, Georgia 4/9 5 Ridgeland, Mississippi 4/10 2 Chattanooga, Tennessee 4/11 1 Marrietta, Georgia 4/13 4 Edmond, Oklahoma 4/13 5 Rogers, Arkansas

>From Dr. William Calvert, Austin, Texas: "Monarchs have now (as of 4/15) re- populated the southern 1/3 of eastern North America, in a line extending through Georgia, Tennessee, Arkansas and Okalahoma. There are still virtually none in west Texas, however! In central Texas monarch eggs and caterpillars are plentiful."

When will monarchs arrive further north? The chart below shows the length of time at each stage of the monarch's life cycle. Remembering that adult monarchs are not thought to live more than 4 weeks, and it has been 3 weeks since they departed the wintering colonies, when do you think monarch sightings will be reported from Nebraska? North Dakota? Pennsylvania? Maine?

STAGE #DAYS AVERAGE (range) Eggs 3- 5 4 Larvae 9-18 12 Pupae 9-18 12

TOTAL 21-43 27

(Note: Temperature controls the rate of development. Monarchs develop faster when the weather is warm than when it's cool. Keep a close eye on the weather when predicting the rate of migration to points north!)

Nature Notes:

"Do both female and male monarchs migrate north? Both sexes do return north after wintering in Mexico, but probably more females arrive than do males. It seems that smaller males are more likely to mate in the colonies, and not make it back north. The reason for this isn't known. However, some males do migrate north and mate. These males have an advantage, in that they are more likely to fertilize the females' eggs. This is because females mate several times, and the last male fertilizes the most subsequent eggs. This is what I do my research on." Dr. Karen Oberhaueser, entomologist, University of Minnesota

"Sighted one monarch last Thursday, April 7, 1994 in my front yard in Junction City Kansas (130 miles west of Kansas City). That has been the only one I've seen so far, although with temps in the 70's the past 2 days and now a cold front blowing in from the north I'm sure more will drop out of migration flight." Chuck Otte, Junction CIty Kansas Internet: cotte@oz. oznet.ksu.edu

"While in Alabama during our spring break we saw about 10 monarchs. We were near the Gulf shores."

"Today is April 13th. We saw a monarch in our backyard. It is very breezy here in Tulsa, Oklahoma and the monarch did nnot land where we could get a good look at it. Our home is located near the Arkansas River and wwe will go down to look for more milkweed and monarchs."

"I've lived in the Mississippi Valley of Illinois most of my life (33 years) and I remember back as far as when I was 5 or 6 and sighted monarchs every spring. We then lived next to an abandoned farm and the milkweeds were thick there. One year I remember that all you could see in the field were hundreds, or maybe thousands, of monarchs. That field is gone now, but I have planted milkweed in my yard and hope to send a sighting report in mid-May!" Thomas Boll

Copyright 1994, Journey North. All Rights Reserved.

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