by Paul Cherubini » Mon Sep 08, 2008 7:04 pm
No it's not too late. During the 2nd week of Sept. in 1989 I found a full grown monarch caterpillar up at Malta, Montana. And during the first week of Sept. in 1992 I found another one just a few miles east of Billings, Montana.
You might have better luck spotting caterpillars near sunset and also in the morning when the caterpillars are more actively crawling over the upper parts of the milkweeds. During the middle of the day and during the afternoon the caterpillars tend to hide in nearby grass or other concealed areas. Also, look at the undersides of the milkweed leaves as sometimes they are hidden under there. And look for caterpillar droppings as that is another clue that they are present.