Swallowtail caterpillars have an bright orange/red fleshy organ called an osmetrium. It looks like a serpent tongue that they stick out when they are disturbed to scare off predators. Osmetria give off a bad smell when stuck out – from two chemicals released from it. I came across this one on an Satuma orange tree in my backyard garden. When I touched the branch – look what happened!
Jacqueline D'Elia Computer geek that loves writing, photography, and building wordpress sites. Earned a BS in Horticulture at Texas A&M. She gardens in Houston Texas and enjoys growing organic food in her raised bed garden. You can follow her garden antics on Twitter @JDElia. Her day job? Selling real estate at RE/MAX Vintage in Houston.
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great photos Jackie!
Thanks Trisha.
UNBELIEVABLE! I learned something new today. Wonderful Photos!
Thank you Lucy. I was surprised – I had no idea that swallowtails did this. I learned something too!
Crazy photo! What a shot! love it!
That is so awesome!!!! Poor thing looks like Adams Familys’ Cousin It of the caterpillar world. LOL
Great photos. The public needs to know about this phenomenon of swallowtail caterpillars and be prepared to look for it in their home gardens. The Ft. Bend Co. Master Gardeners have an Entomology committee that actively helps educate gardeners about the critters in their gardens and studies hard to learn more about Nature’s insects, etc.
Beautiful photos. I always learn something from your posts. Thank you for all you do to help gardeners
Thanks for the beautiful photos! I plant dill just for the caterpillars which love that plant and have noticed the same reaction/smell when transferring the dill caterpillars to another plant. They can be quite feisty – and, if I were a predator, I’d leave them alone as well since the smell is quite distinctive!
I think I have the same critters eating up my young grapefruit tree. Last year they attacked my young lime tree. I won’t disturb them because they will be butterflies one day, but it is annoying to loose all those leaves! I blogged about it as well. Thanks for sharing.
You can put this citrus oil on the tree for that reason. It will not kill the caterpillars only keep them from gettting on the tree.
Thanks for the tip, Paula!
I have 2 and they have been eating my orange tree leaves. Not very pleasant odor… Nothing seems to kill them, now what do we do?
Why would you want to kill them? Rarely do they do enough damage to affect the health of the tree. The butterflies they do become are beautiful.
Just removed one from my Satsuma Orange. They must like them.
What a fantastic sequence of photos Jackie. Winston Churchill would be proud
These are great caterpillars to find.
Found one of these on our lime tree today. Thanks for identifying it!
Your photos are absolutely amazing. I am really intrigued by butterfly’s and have been shaping my garden over the past three years so I really appreciated your post.