Date: 05/07/2006

Number: 1

I have been looking at "along road" and "off road" milkweeds. There are virtually no larvae to be found on the off road milkweeds but 50-80% of the ramets of common milkweed of 6 inches or more contain evidence of extensive feeding and 40-60% of the crowns (meristems) contain larvae
- often 2-3.

In about two hours of driving slowing along remote dirt roads over the past few days, I've found almost 200 larvae. It has been cool and the degree days for larval growth have been minimal since the arrival of a small wave of monarchs during the 14th-19th of April. The cool weather has slowed growth but also has reduced activity of predators and parasites. The larvae are all at the tops of the plants, probably the warmest sites since the cupped leaves may gather a bit of incident radiation.

If I had the time an inclination, I'm confident that I could locate 40-100 larvae, and perhaps many more in some areas, per hour.
Altogether, the number of larvae is rather astonishing for this time of year but as I will point out in the Update, these numbers are not necessarily a good sign due to the extended development time of larvae starting at this latitude in April. I'm about to grab the camera to take a few pictures of a late second instar larva I've been following that is now at least 22 days old!

If it warms up soon, most of these larvae will disappear due to predation and dispersal.

If you are looking for monarch larvae, check those milkweed shoots emerging from the gravel along remote dirt roads.

Courtesy of Monarch Watch

Lawrence, KS

Latitude: 39 Longitude: -95.2

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