A Saturniidae bee mimic?

More Saturniidae moths were posed around my light tonight and one looked to be a different species within the genus Automeris. I poked it to see if its eyespot display differed from the other Automeris species I have seen (and poked). To my surprise it didn't reveal eyespots, nor did it fly away. Instead, it raised its wings up behind its back and fully displayed its yellow body with a black stripe. See photos below:

Before:

Post-poke:


To me it [vaguely] resembles a bumble bee. I have never heard of this behaviour or defensive strategy in Saturniidae moths, but it is incredibly interesting. Bees are common models in mimicry systems - especially in mimetic flies (e.g. Syriphidae). By resembling bees or wasps (sometimes relatively poorly) mimetic flies avoid persecution by birds so there is no reason to think that a similar strategy wouldn't work for these moths. Please leave a comment if you have any information about this species or thoughts of the defense mechanism !

I didn't get a look to see if it also has eyespots hidden in the wings. This would be interesting to know, because so many Saturniidae moths have eyespots. It is possible that this one does too and just doesn't use them. It would be interesting to know whether this species evolved from an ancestor that used the eyespot-defence. IF so then it raises some interesting questions:

· What conditions made individuals with the bee mimic defence better than ancestors with eyespots?
· Why don't more Saturniidae moths use a similar defence?

4 comments:

  1. There are some pretty amazing Hymenoptera-mimicking Lepidoptera here: http://bugguide.net/node/view/33289. Strange that you should find such discrete strategies (eyespots and Hym-mimicry) in the same family...

    My second thought was that it could just be warning colouration to indicate the presence of barbs or something else nasty, rather than Hym-mimicry per se...

    If this thing does have eyespots that would be pretty confusing, though. It would be like saying simultaneously "Look, I'm a big bad predator that will eat you, but also a little bee that will sting you!"

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  2. Looks like it relies heavily on camouflage when resting. Perhaps its "plan B" is simply changing appearance to look both bigger and strange/unusual/confusing.

    Did it move into this position in a flash, or more slowly? Did it vibrate its wings?

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  3. Katatrepsis: You're right, it is odd that there should be the 2 discrete strategies in 2 species that are probably [relatively] closely related - probably the same genus at least. Also, good point about the warning colours - I suspect that it is palatable though.

    XPreNN: I agree that it is a "plan B" type strategy, used when they are detected by a predator. The posture change is elicited by touch, and was done quickly ("in a flash") just like the eyespot display of other Automeris here in Costa Rica. The wings were not vibrating though.

    More thoughts/insights are welcome!

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  4. Hylesia lineata an urticant moth, all moth of this genus have this defensive behaviour and also other Saturniid like Dirphia...I don’t think it’s for look like a bee or a wasp ….

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