Green and Black “Topa Worms” Probably Cankerworms

Share the knowledge


One of our readers sent us an email describing some worms that they had found on their trees. She said that they had always called them Topa worms and the tree a Topa tree. They said that these worms are black and green and they literally strip the trees of the leaves until all of the leaves are gone from the tree. They are not sure where these worms came from or if they will die after the leaves are all gone. They did not send a picture, but there is a possibility that these are cankerworms.

Cankerworms are very destructive inchworms that are the larvae of geometrid moths. There are two different types of cankerworms, spring and fall cankerworms. Their names are given for the seasons that they emerge. This could be why our reader is just now seeing these worms on their trees. They are usually green with black spots, but can also be brown.

These worms feed on the larger leaves of many different trees such as elms, oaks, ash, and hackberry. They prefer the much larger shade trees that have very big leaves. They feed on the leaves and will continue until all of the tissue and veins are gone. If they are feeding on the much older trees, there will be very little effect on them. The more mature trees will only show slower growth in the leaves. If they are feeding on younger trees however, the trees will become very weak and start to die.
In summary, our reader wanted to know what were the black and green “worms” that were eating her Topa trees.  Without a picture we can’t be sure, but there is a good possibility that they are cankerworms. These worms can eventually kill younger trees by eating all of their leaves. They will feed on the leaves until there are no more. Then they will move onto another tree. Our reader wanted to know where they came from. These worms come out during different seasons and these are more than likely the fall cankerworms since they are just now seeing them. If our reader wants them to go away, they can always pick them off the trees that they are eating and place them on another tree. Once they are ready to become moths, they will disappear.


All About Worms is always free, always reader-supported. Your tips via CashApp, Venmo, or Paypal are appreciated! Receipts will come from ISIPP Publishing.

CashApp us Square Cash app link

Venmo us Venmo link

Paypal us Paypal link

Note: Some links on this site are partner links. That means that we earn a tiny bit if you purchase something through them, at no extra charge to you. This helps offset the cost of keeping this resource free for everybody (it doesn't cover our costs, but every little bit helps! :~) )
Green and Black
Article Name
Green and Black
One of our readers sent us an email describing some worms that they had found on their trees.

Share the knowledge

Author: Previous Author

Leave a Reply

Your email address will not be published. Required fields are marked *