Monarch butterflies and caterpillars have various predators in spite of their defenses. They also have to deal with parasites and diseases. This page will show photos and videos of some situations that didn’t turn well for the insect. Please also check this page for issues around pesticides.
YELLOWJACKETS AND BALD-FACED HORNETS
These insects are predators that feed their young with other insects including caterpillars. However their own diet as adults is sugars such as nectar from flowers. From what I could observe they would not bother the large Monarch caterpillars feeding on the same Swamp Milkweed plants that they were collecting nectar from. Which doesn’t mean that they did NOT prey on young caterpillars though.
|Bald-faced hornet on
|Yellowjacket on Swamp milkweed
|Parasitic tachinid fly
THE CHRYSALIS UNDER AN INUKSHUK STONE
One morning I found a Monarch chrysalis under a stone of the inukshuk in my garden. That stone structure is around 1.5 meter (4.5 ft.) away from a Swamp milkweed clump, but it sits on a raised bed of stones held in place by a large wooden border.
How this caterpillar was able to crawl across all those obstacles to reach almost the top of the one meter (3 ft.) high inukshuk is a mystery!
The chrysalis didn’t look right. It had what seemed like a hole and a transversal crack in the middle on one side.
Its dark color seemed to indicate it was near emerging as a butterfly, but instead it turned completely black after a few days while remaining intact (no parasitic larvae came out of it). And after a few weeks, it had vanished.
|Chrysalis has a hole and a crack
|Long trip full of obstacles
for a small caterpillar
|Monarch caterpillar crawled near top of inukshuk
THE EMPTIED CATERPILLARS
I also found a dead caterpillar hanging down from the underside of a Dusty Miller leaf near the Swamp milkweed clump where it came from, so it was in the ‘J’ stage. Its internal juices were sucked out and all that was left was a flat skin.
There was also this dark, shriveled and shrank Monarch caterpillar with some silk attached to its end. Was it killed by a spider?
|'J' phase dead Monarch caterpillar
|Monarch caterpillar was
emptied of its juices
|Monarch caterpillar killed by spider?