That time nature came to visit
What’s eating my lime tree leaves? Said the Facebook message from my adult daughter, along with some photographs.
I had just arrived home from a working bee checking for new rabbit burrows on a walking trail on an old railway corridor full of remnant vegetation.
The photos were of a beautifully patterned larvae, a caterpillar, of a butterfly or moth, and some well chewed leaves.
The dead lesions or spots on the leaves are probably Alternaria brown spot, a fungal disease Alternaria alternata, which occurs in humid conditions.
The missing pieces on the leaves are caused by the feeding of the larvae, they are a chewing insect, but may also be caused by slugs, which hide under pots during the day and come out and feed at night.
If you have plants with chewed or missing leaves, or new vegetable seedlings that disappear over night with no apparent cause, look for slugs first, hiding somewhere nearby.
It took me awhile to identify the larvae using pictures on the internet SA Butterflies and Moths it is a Swallowtail butterfly larvae Papilio anactus, and they do like citrus, in this case the lime tree.
I then sent a photo of the butterfly to my daughter suggesting it is such a beautiful caterpillar and butterfly, you could just leave them, if the leaf damage isn’t too extensive.
Or pull them off with a twig into a container and move them to a large citrus tree down the road somewhere. My daughter and her husband both laughed over this suggestion, and upon reflection it wasn’t a very good idea for those people down the street with a citrus.
And don’t use any dusting powder or insecticidal spray as they are too dangerous for humans and dogs I said, and suggested, you could use a microbial insecticide like ‘Success’ which contains bacteria that attacks caterpillars and as such is safe for humans.
A few days later one of the larvae had made a chrysalis; following the insect’s life cycle is interesting, egg-larvae-chrysalis-adult butterfly, especially when it is in your garden.
My daughter decided to let the larvae stay on the young lime tree’s leaves and enjoy watching the Swallowtail butterfly life cycle progress. She thought it was well worth a few chewed leaves to let nature take its course and have some beautiful butterflies flying in the garden.
I like to think that nature came to visit, and was showing a young family her wonders, including showing Granddad (me), but of course nature was there all the time, we just need to look and take care.
Declaration of competing interest. I have no conflicts of interest to disclose.