The photo, above, shows how they should normally look, however, last week, they looked like this….
Definitely not normal looking and manyM of the outer leaves were skeletonized, and it got worse. All four of my yellow bell shrubs had the same symptoms. So, did my orange jubilee shrubs, which are closely related.
To be honest, I was a bit stunned to see the damage. You see, I had grown these beautiful shrubs for over 14 years and have never seen this before – not even in landscapes I managed or when consulting.
What was interesting is that other shrubs right next to my yellow bells and orange jubilee weren’t in the least bit affected. So, what is eating my leaves?
I looked at the symptoms – the skeletonized leaves, the fact that many of my leaves were ‘rolled’ and little black dots (insect poop) told me that my shrubs were suffering from ‘leaf rollers,’ which are tiny caterpillars that roll the leaf around them while they eat. It is hard to spot the caterpillars themselves, but the damage they cause, usually makes it easy to diagnose.
Now that I noticed my yellow bells and orange jubilee shrubs being affected – I have noticed these same shrubs being affected in my neighborhood, along freeways and other areas. I don’t know why leaf rollers are affecting these shrubs all of a sudden after all these years. I suspect it is the higher than normal rainfall we experienced this summer, but I don’t know for certain.
Regardless of why leaf rollers are affecting these beautiful shrubs – there are ways to get rid of them. Here are a few different options:
1. Prune off the affected growth and dispose of the leave in the trash can (not in your compost pile).
2. Treat your shrub using a biological pesticide that contains BT (Bacillus thuringiensis), which is ingested by the caterpillars. BT basically ‘eats’ its way from the caterpillar’s stomach outward. I use Safer Brand 5163 Caterpillar Killer II Concentrate, 16 oz.
3. You can use an insecticide spray to kill the leaf rollers.
4. Lastly, there are systemic insecticides that are applied around the plant and are taken up by the roots – but, their use can lead to the build-up of resistant insects and can have other negative environmental effects.
**Whenever using any pesticide – follow directions carefully. For my shrubs, I will prune back the damaged growth and not apply pesticides. However, if the leaf rollers continue to attack, then I may decide to use a product with BT.
**If your bougainvillea leaves are showing signs of being chewed – they may have been visited by ‘bougainvillea looper caterpillars.’ For more information on how to recognize and treat these caterpillars, click here.