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Monarch Butterfly Series - December caterpillars

lcurtx's picture
Sun, 01/01/2012 - 12:37am — lcurtx
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Library topic: 
Entomology -insects
Library shelf: 
Educational articles
Location: 
Kingwood TX
United States
See map: Google Maps

The Monarch migration for Fall 2011 has completed.  The droughts, pesticides, and habitat destruction continue to impact the survival of the Monarch eastern population and the great migration.  Millions of monarchs annually make the migration to the Winter sanctuaries to escape the freezing temperatures in Eastern US and Canada.   Some of these Monarchs travel 2,000 miles and wait in Mexico until Spring where they return to Texas to lay their eggs on Texas milkweed.   Texas is the most important state.  Texas is where the 1st generation eggs are laid.  To lay eggs, the Monarchs must successfully find lots of Texas milkweed.  Monarchs live short times and have 4 generations each year.  The 4th generation migrates back to Mexico.

The interesting thing is not all 4th generations returned to Mexico.   Instead some of the 4th generation stopped and deposited eggs in the Houston area during December.   There is of great interest in documenting where December Monarchs are being seen.  As a result, a couple grad students will be visiting the Houston area to study this closer in January.  In addition, a special interest is being taken regarding OE infection rates in the Houston Monarch overwintering population.   Is the OE rate worse in Spring or in the Fall?   Is the problem getting worse?

Still some areas did not see any caterpillars at all on their milkweed all year long in the Houston area.  Normally if a Houstonian planted milkweed they would get eggs.  This has been the case for two years now.  The numbers of Monarchs successfully reaching and surviving the winter in Mexico is at it's lowest.

Currently caterpillars are documented in the following areas with diminishing milkweed supplies:

Kingwood, Humble, Friendswood, Alvin, Sugarland, Freeport and Galveston

Where are you seeing Monarch adult butterflies, caterpillars or eggs?   What variety of milkweed (Asclepias)?

Be sure and document your Monarch sightings on Journey North.   http://www.learner.org/jnorth/monarch/index.html

To learn more about Texas milkweed see:   http://www.asclepias.org

To learn more about OE see:  http://monarchparasites.uga.edu/whatisOE/index.html

Happy Winter Monarch Watching,

Linda C.

Photos

Comments

Fri, 01/06/2012 - 9:07am — Visitor

I have lots of caterpillars - Kingwood

A second site I monitor in Kingwood now has 36 caterpillars which has 34 caterpillars on one plant and two on a second plant. I have located more milkweed. Some milkweed survived the couple light freezes we have had so far this winter. I lost most of my milkweed in my yard in Kingwood with about 15 surviving caterpillars. The caterpillars are growing slower in the cold wet weather some how still surving. Predators seem to not be present, so no impact and giving caterpillars a chance. Weather seems to be mild for several more days. I will rearing most caterpillars at some point and then doing non-fatal OE testing and data collection on all butterflies. NOTE: My Texas native milkweed has finally decided to go dormant. No eggs deposited on the native. All locations reporting caterpillars have been tropical milkweed aka Asclepias Currassivica.