HELP: Something eating my Yucca Cane

[iamGavinJ]

Hi,
I was tending to my Yucca Cane this morning and noticed small piles of dried pulp on some of the leaves. I trimmed one of the leaves which looked quite unwell and found the core of the leaf had been eaten and hollowed out by a bug.

I was unable to find the offending freeloader but the gnawed out track looks to go quite deep down into the stem. I guess it's living somewhere down in there.

I'm not much of a green thumb, though I try, and I do love my indoor plants. What should I do?

Please help.

 

[Marck]

Hi Gavin:

This looks like evidence of a beetle infestation. Either the Yucca Snout Weevil (Scyphophorus yuccae) or the Agave Snout Weevil (Scyphophorus acupunctatus), which also eats Yucca sp. has infested your plant. The adult weevil has emerged from an exit hole in the leaf, but it is likely that the bore hole goes into the stem.

These weevils can kill Agave and Yucca, so action is essential. Cut away and dispose of any infested plant material, put it in a sealed plastic bag so that no more adult weevils can emerge. Further infestations can sometimes be prevented by using toxic pesticides. I don't take the use of such chemicals lightly, but the choice is yours. Such pesticides are bad for the environment and for human health. Sometimes the wisest course is to replace the plant, perhaps with a different species that is not pest suceptible.

The UC IPM (Integrated Pest Management) Website is a great resource for plant pest issues, in California and also elsewhere.

Managing Pests in Gardens: Trees and Shrubs: Invertebrates: Agave and yucca weevils—UC IPM

Information about managing pests of gardens and landscapes, from UC IPM.

ipm.ucanr.edu

 

[iamGavinJ]

Hi Gavin:

This looks like evidence of a beetle infestation. Either the Yucca Snout Weevil (Scyphophorus yuccae) or the Agave Snout Weevil (Scyphophorus acupunctatus), which also eats Yucca sp. has infested your plant. The adult weevil has emerged from an exit hole in the leaf, but it is likely that the bore hole goes into the stem.

These weevils can kill Agave and Yucca, so action is essential. Cut away and dispose of any infested plant material, put it in a sealed plastic bag so that no more adult weevils can emerge. Further infestations can sometimes be prevented by using toxic pesticides. I don't take the use of such chemicals lightly, but the choice is yours. Such pesticides are bad for the environment and for human health. Sometimes the wisest course is to replace the plant, perhaps with a different species that is not pest suceptible.

The UC IPM (Integrated Pest Management) Website is a great resource for plant pest issues, in California and also elsewhere.

Managing Pests in Gardens: Trees and Shrubs: Invertebrates: Agave and yucca weevils—UC IPM

Information about managing pests of gardens and landscapes, from UC IPM.

ipm.ucanr.edu

Thanks @Marck appreciate the help.

 

[Chuck]

It is also possible that the plant is infested with Common Stalk Borer. I guess the easiest way to determine which of the above it is, is to smell the hole going into the main stalk of the plant. The Agave Weevil doesn't kill the plant but the bacteria it carries does and this bacteria has a very bad odor to it. The larvae of the Agave Weevil eats the bacteria-infested core of the plant and Bt, although it will kill the larvae, will not help because the bacteria is what kills the plant, not the larvae. If it is CSB the remedy is Bt injected into the hole and into the core of the plant. If there is a bad odor I don't know if there is a remedy or not. Here in Texas ranchers rather welcome both of them as they kill Spanish Dagger plants and other plants detrimental to livestock.