Knowledgebase
Yellow spots & holes on Cistena purple leaf (Purple Lesf Sand Cherry) #876788
Asked July 11, 2024, 9:25 AM EDT
I have 2 bushes on the front east side of my home. Sections of the leaves have yellow spots and holes. Other sections have holes. I found one small insect on a leaf. Is this eating my bushes and causing the yellowing? If yes, what is it and how do I treat them. If no, what is causing this and how do I treat the bushes? Thank you
Weld County Colorado
Expert Response
Hi, Nicole,
Thanks for contacting Ask Extension. My name is Kathy, and I will be helping you today.
Thank you for the pictures. They were very helpful in understanding your issue.
From the picture with the larva, the problem appears to be from pear slugs, which are the larval stage of pear sawflies.
This CSU Fact Sheet discusses them in more detail, including pictures that confirm the identification of the slug and the damage it causes.
CSU Fact Sheet 5.560 – Pear Slugs
https://extension.colostate.edu/topic-areas/insects/pear-slugs-5-560/
CSU Fact Sheet 5.547 Insect Control: Soaps & Detergents
https://extension.colostate.edu/topic-areas/insects/insect-control-soaps-and-detergents-5-547/
There are several choices for control. First, a forceful jet of water spraying the leaves can dislodge them.
There are also several insecticides which may control them, as well as soap or detergent sprays. These are listed and discussed in the 2 Fact Sheets above. If using one of these methods, always read and follow the manufacturer’s instructions. Pay particular care with these, since the treatment may harm beneficial insects as well as the pear slug.
Please review the attached information, and if you have any additional questions or this or any other gardening issue, feel free to contact Ask Extension again.
Thank you,
Kathy
