I have an indoor meyer lemon tree (outdoor in the summer) which is having it's leaves eaten by some sort of bug. I've never caught the culprit so it must be a night time critter. Any ideas for me?
If something is eating the foliage at this time of year, it must be on the plant or in the soil. During summer, grasshoppers will often eat lemon tree foliage. But the grasshoppers wouldn't likely be found indoors for more than a few days. More likely, slugs or snails are causing the damage. These pests do feed at night and hide in the soil or under debris during the day, then crawl up the plant at night to feed. You could try placing slug traps on the soil surface to see if you catch any.