(no subject)

[soc_puppet]

Kinda stunned to learn today that relatives of the monarch butterfly are known for killing and eating larvae of their own species. Apparently it's a good way for the males to get extra milkweed juice in them? They can get it directly from the plants by scratching leaves and drinking the juice, but milkweed butterfly larvae have it more concentrated (and possibly easier to digest), and extra milkweed juice apparently makes male milkweed butterflies into super studs or something.

And I just. It's apparently been happening with milkweed butterflies in Asia, and I'm left to wonder, is this what's been happening to the monarch butterfly caterpillars around here? Because I've seen some over the past few years, but they've all been disappearing before I see any chrysalises! And I know that lacewing larvae can eat monarch butterfly eggs, but I thought that the caterpillars were still relatively immune to predation due to tasting like milkweed, which most other animals think tastes terrible? But if it's the actual grown butterflies doing the killing and eating, that would explain it.

Anyway, the article I saw didn't mention monarch butterflies specifically, so I may be jumping to conclusions that are fragile at best, but I am definitely perplexed as to where all the caterpillars have been going. Do I need to start raising them inside once they hatch? I'm prepared to do it!

Sigh.

Comments

[game_byrd]

I don't think butterflies have the mouthparts to eat caterpillars. But other caterpillars do.

If this is a thing that happens, then it's a thing that's been happening as long as caterpillars have been around. So the recent population crash among Monarchs has to be due to something else.

[soc_puppet]

Eat was, perhaps, not the correct word; "drink" is more accurate. Anyway, here's the article; the behavior has only been observed recently, and only in Asian subspecies, but it doesn't seem like one that would be very successful in the long term.

It's not just the general population crash; it's the fact that I've seen monarch caterpillars in our garden, eating milkweed we make sure to grow for them, and then... they disappear. Small ones, big ones, doesn't matter! I was keeping an eye on one that got to be a good inch long, really close to metamorphosis, and then it was gone, no chrysalis in sight. Monarch caterpillars are supposed to be safe from predators on account of their diet making them taste nasty, but if that's the case, where the fuck did the specific, extant caterpillars in my backyard go, as opposed to metaphorical, generalized caterpillars (who are likely prey to climate change and other human-caused environmental changes)? I've got photographs of a lacewing larvae sucking a monarch's egg dry, so that would be the other culprit I've got in mind, but otherwise I'm stumped.