Sluggin' Along: Swimming Ladybug - Hemolymph Hypothesis

While refilling the birdbath a few weeks ago, I noticed that a Ladybug had fluttered too close to the stream of water and had landed in the bath. Thinking that the ladybug might drown, I put down the hose and rushed to the bath. I dipped my finger into the water and lifted out the ladybug. It was still alive! Then I dropped it into the water and it swam around calmly before crawling out onto the dry stone. It then proceeded to dry itself off in the sun. I felt like a silly, ever-worrying human. Of course God has equipped His creatures to deal with varying conditions.

This particular ladybug is properly known as a Multicolored Asian Lady Beetle (Harmonia axyridis).

Ok, so this is the state in which I found the ladybug...

On my finger...

Back in the water...

Time to dry off...

Then the ladybug engaged in some curious behavior. Ladybugs are capable of "reflex bleeding" or "autohaemorrhaging", in which they secrete a sticky yellow substance containing isopropyl methoxy pyrazine, a chemical present in their hemolymph (blood). A ladybug releases this foul-smelling chemical from its legs when it feels threatened. This specimen brought the thick yellow fluid up and started to rub the white portions of its pronotum with it. However, I'm not convinced that the ladybug was doing this because it felt threatened. If my presence had triggered the reaction, I'd expect it to have reflex bled on my finger when I picked it up earlier. This seemed more of a reaction to being wet. Moreover, the hemolymph didn't remain on the ladybug's pronotum. You can see globs of it on the stone. Also, the ladybug flexed its elytra, revealing its abdomen. If it felt threatened, I wouldn't expect it to make itself so vulnerable like that. So, my hypothesis is that the hemolymph might act not only as a defense mechanism, but a waterproof agent as well, or at least something that soaks up the water, removing it from the ladybug's head and pronotum.