Question
QUESTION: I live in Arizona. I have 3 Yellow Bells and a couple of Hibiscus plants that are being eaten by a bug I can't see. It starts out as a white spot about 1/32" on the top of the leaf. When I scraped it with a pin it came off BUT there was no sign of an insect,i.e worm  or bug. However, soon the leaf is half eaten, the edges are brown and dry and some of the leaves are curled. I have tried to see an insect mornin noon and night with no luck. The leaves still are being eaten. There are sections of a few leaves that have a brown "trail" that appears to be a worm. However when I scrape this it falls off and nothing comes out of it. I know the small white spots are the beginning as I watched 2 leaves go fom a white spot to being eaten almost totally AND still I can't find the insect to identify. So far I have used an insect killer that was for ants with directions for diluting for other insects..didn't dent then..I am using dish soap and water spraying leavs. May have worked a little. Help please

ANSWER: Jonathan,

When you say "half eaten" do you mean that half the leaf is gone or that it has dried up? The leaves turning brown and curling is usually a symptom of disease rather than an insect (aphids can cause this as well). If the leaves are missing I'd suspect something like slugs. Have these plants been outside, perhaps last summer? Post a follow up and I'll help you figure this out.

Jack DeAngelis
http://www.livingwithbugs.com



---------- FOLLOW-UP ----------

QUESTION: Half eaten..one day it is a full green leaf..the next day it is half gone,still green just half eaten..what about the white spots? and yes these shrubs are out doors for 7 years with no problems..the whole leaf is not brown..just the edges..also remember there are no visable insects..I know what aphids are and slugs are not there..The progression is just as I indicated..green healthy leaf..white spot appears..next leaf begins to get eaten..I want to know what the white spot is as this is where it starts..

Answer
There are only a few things that will consume that much leaf material. Slugs, earwigs and caterpillars will do this and since slugs typically feed at night I think this is the most likely culprit. I don't think the white spots have anything to do with the missing leaf material. There are no leaf-feeding insects that first appear as small spots. If you post a picture I may be able to get a better idea of what this looks like.

Jack DeAngelis