Many have shared the complaint “something is chewing holes in my plant” and I have yet to get a straight answer…..
Roses, lupine, dahlia, eggplant and petunias alike share the damage symptoms of this pest’s appetite for disaster. What the mysterious part is that the aftermath of a meal is clear, but who or whom is causing this damage is not. I have received tons of complaints from customers as well as had it happen in my own backyard. The latter led me to dive into some research.
My first theory was that this insect only comes out to feed at night and that’s simply why no one ever sees them on plants.
I have noticed two types of damage exhibited. Notches at the edges of the leaf as well as holes in the center of the leaf. I found that the different damage is caused by different pests.
The notches, for a wide variety of plants is most likely caused by the leaf cutter bee (Megachilidae). This pest causes very mild damage that, unless a great population has arrived there is no need for any human intervention. The leaf cutter bee does not actually eat the plant, so using a pesticide may not be effective. Since they are bees they are beneficial to us in terms of being pollinators. And since they have wings and don’t stay in one place for too long could possibly be why no one catches them in the act.
Now the holes in the center have caused me great displeasure and with as much damage as is on my eggplant I can’t help but feel that it is effecting my fruits. With such a large portion of leaf missing I don’t believe it can photosynthesize like it should.
These are not my photos but an example of what damage I am dealing with. After spending a few days back and fourth on a few websites I have found that the insect with the most similar habits is the caterpillar. They chew as they move around that is why some of the irregular holes are located mid leaf and some carry off the the edge. The safer methods of control are: handpicking, insecticidal soap and bactillus thuringiensis kurstaki (Btk). An excellent control of leaf-eating caterpillars such as cabbage worms and tomato hornworms, but has no activity against insects that do not eat treated leaves. After the insects eat the bacteria, their guts rupture and they die. Bt is therefore one of the safest natural pesticides you can use in terms of controlling caterpillar pests of vegetables or fruits without harming beneficial insects.
Plant problem diagnosis