Hi Dan,

This is a tough one to identify just based on leaf damage. It could be a number of things. 

Have you purchased a new plant recently? Or were all 7 plants outside last summer?  That might help distinguish if the pest came in with a new plant, or not. If not, I suspect it's a generalist feeding insect (meaning it will feed on a wide variety of plants in Colorado). 
Is there webbing present around a lot of the damage? Or was webbing found only in one area?

Based on the feeding pattern and the presence of webbing, I suspect it may be a species of caterpillar. Many species feed at night which is why you aren't seeing them during the day.

Over the course of winter, have you seen any moths in your house? Have you noticed any insect droppings? They might look like tiny black dots or pellets. 

Have you looked under the surface of the soil? If you are willing, you could gently move some the soil around the plants (perhaps ones with the most recent feeding damage), to see if you any find the presence of an insect. If you can't find the insect during the day, it is likely living the soil. 

Please send more picture of any other signs you find. Based on your answers, we can try to narrow down to what is feeding on your plants. 

Knowing what the pest is will inform control options. 

Thanks,

Lisa 

Lisa Mason
Horticulture Specialist, Entomologist
Colorado State University Extension in Arapahoe County

Hi, Lisa.

I put glue traps in the plant pots last evening and got a number of the insects shown in the attached picture. I did not get any in the pot with the plant with the most damage.

Hi Dan,

Thank you for the additional pictures!!

Based on the damage, there may be several different things going on. Some may have occurred while the plants were outdoors. 

• The pillbugs (roly-polys) on the sticky trap are NOT likely responsible for the leaf damage. They also wouldn't create webbing. Pillbugs feed on decaying matter in the soil mostly. They can feed on new, tender plants but those plants need to be at ground level. They wouldn't be able to climb high on the plant. Their mouthparts are also too small to do that type of damage. 
• The photos with a large of amount of leaf missing is consistent with caterpillar damage, or possibly slugs. When I zoomed in closely to those photos, the edges appear to have a brown line around them? This suggests the caterpillar damage occurred awhile ago. Could it be possible that the caterpillar damage occurred outdoors and the other damage occurred more recently? 
• The photo with the three small circles missing is from a different insect. I am not sure exactly what, but could have been from an earwig, or a variety of other insects that feed on leaves. How extensive are the leaves with small holes? The brown edging also suggests the damage occurred awhile ago. If so, the insect is likely not present anymore unless you see newer damage. 
• The photo of the twig appears to be sooty mold. The sooty mold developed from small insects that leave "honeydew" a sugary substance. Aphids are an example of an insect that leaves honeydew, but I don't see any plant damage consistent with aphids or or other honeydew-producing insects. Finding sooty mold on the branch suggests that there were other insects present on the plant at one point, but that insect may not be a problem now since we aren't seeing any other damage.
• The webbing could be from a number of things. When did that start appearing? My first instinct was spider mites, but I don't the classic flecking/stippling on the leaves. The leaves would be spotty gray/brown colors. 

The best course of action is going to be the following:

• Based on your photos, it doesn't appear that any of the plants are declining in health. Likely a number of insects have visited the plant (some still might be), but nothing that is causing the plant to decline in health. Do you agree? This is good news! 
• Insecticides are probably not going to be effective since we need to have a target pest to treat. For instance, if you had spider mites preset on the plant, you could try insecticidal soaps. For products like this to work, the insects need to come into direct contact with product (same with Neem oil). Applying general insecticides to a plant won't provide any control and some products may limit if you can eat the fruit. 
• You mentioned the damage is getting worse and spreading. Which part of the damage is getting worse?
  Consider removing the heavily damaged leaves and carefully cleaning off the webbing. If you continue to get more of one type of damage, that might help use narrow the focus on which pest continues to be the problem. If you start to notice more discolored leaves, please send in photos. 
• Keep your plants as healthy as possible. Healthy plants can withstand pest problems. Some best care practices available here. 
• When bringing plants indoors next fall, examine them closely for signs of pests. Consider wiping down leaves with a damp paper towel, or lightly spray them with water to remove any tiny insects on the plant. 

Hope this helps! Please reach out if you continue to see more new damage. I'll try to help you narrow down to a specific pest that is causing problems. 

Thanks!

Lisa

Lisa Mason
Horticulture Specialist, Entomologist 
Colorado State University, Arapahoe County

Thanks, Lisa.

Hi Dan,

Are the new chewed up leaves similar to caterpillar damage (entire chunks of leaf missing), or smaller holes missing in the leaves?

Thanks,
Lisa

Entire chucks of leaves missing
Sent from my iPhone



Hmmmm.... I am still trying to figure out what might be causing new damage. 

Have you seen any signs of slime trails from slugs? Slugs can leave that type of damage. You could try making a slug trap. 

Directions from our fact sheet on slugs:

Slugs are attracted to chemicals produced by many fermenting materials. These materials can be used to make attractant traps (pans or small containers (e.g. a tuna can) of beer or sugar-water can attract, trap and drown slugs. A single baiting can remain effective for several days, as long as sufficient liquid remains. However, because the range of such traps is only a few feet, place them throughout the plant to reduce slug populations. Alcohol is not an attractant to slugs.

If the feeding damage is from slugs, hopefully the traps could catch most of them in your plants. You could try one plant (with the new damage), and if successful, add containers to your other plants. 

Thanks,
Lisa

Lisa,

No slugs or worms in the beer traps this morning. 

Hi Dan,

Just checking in: Are you still seeing new damage? Have you seen any insects? 

Lisa

I have grow lights on them and the trees are now putting out new growth. I have not seen damage on the new leaves yet, though I see some damaged old leaves.

Hi Dan,

Okay, glad you are seeing new growth! I am sorry we weren't able to pin down the exact cause of what was eating the leaves, but keep me posted if you do see new signs or symptoms. 

Thanks,

Lisa

Lisa Mason
Colorado State University Extension