A Gardeners Forum Forums General Discussion The House Plant Forum Avocado tree pest infestation, please help

I started an avocado tree from a seed over a year ago, I think 7/17 is the date I put his seed in water, but I'd have to check. It's somewhere around there though.

Anyhow, he's already dropped all his leaves three or four times because of this bug he's infested with. They're tiny, white, non-flying and live only in the soil. I've never seen them on the stem or leaves. The first thing I did was remove his soil and put new soil in. He wasn't happy and dropped the last of his leaves, but the bugs appear to make him drop his leaves also. He had already started then when I switched soil it put him in shock. His leaves grew in again and he had a second shoot coming up on his stem.

They came back.

I drenched him in pesticide for a week or two straight and it ended up making him drop all his leaves (this was in the winter) but the bugs appeared to be gone. He grew his leaves back and was fine.

When they came back again I got a new bag of soil and switched out his other soil completely and sprayed the inside of his pot with pesticide. Again putting him in shock. His other little branch was drooping and he had leaves on him so I used a chopstick and pencil that was taped together to put in the dirt, tying him up to it so he wouldn't droop. The bugs were gone long enough this time for him to regain his strength and I was able to get rid of the chopstick so he could hold himself up. He had six beautiful leaves and was growing more when they came back YET AGAIN.

I know this is a long post, but I'm trying to give as much information as possible. He gets watered weekly on fridays and lives inside near the sliding glass door. He gets partial sunlight throughout the day, I didn't want him to be exposed to sunlight directly all day since he's just a baby and sensitive.

Also, sometimes I can see the bugs when I blow on the top of the soil. When they are out they freak out and burrow back under.

If I got ladybugs and a net to cover over him, do you think the ladybugs would eat the mystery pest? And what kind of bug do you think is infecting him? I've looked all over and the only common houseplant / avocado pests don't look anything like them. :[

Welcome, Amber.
Those are probably larva of one or another insect and may well be the larva of the fungus gnats you have. Aside from cutting back on soil watering, if these are the larva of the fungus gnats, you could but some mosquito dunks, one of the Bacillus thuringiensis bacteriums, on the soil and that could help. These are found in pond sections of your nursery.
But my favorite cure would be to take a squirt of dish detergent mixed with water and spray the soil surface daily for a couple weeks. Not saturating the soil just covering the top of it. And then continue this every time you see an issue.
Avocado babies are sensitive so every time you re-pot or do much of anything to change them, they will drop leaves.

Thanks for the reply. I have often called my little one a cat in a trees body, hah! He seems to have never-ending lives. Which I appreciate, I don't want to give up on him. Sound so silly.

How much dish detergent should be mixed with water? I've seen a few suggestions. I'll make sure to note the mosquito dunks, hopefully I can pick some of that up soon.

I use about a tablespoon of detergent per quart of water. But I don't really measure. I just squirt it in after filling the bottle with water. For soil you could up the dose a bit but not for the leaves if you are using the spray for those.
The detergent makes a sticky film that the bugs cannot fight through easily. It can also choke off their air a little. It is just the easiest/cheapest thing to use.

At the moment he has no leaves, so I won't need it for that. Plus, I've never seen them crawl on the stem or leaves. I'll start with that and if it doesn't clear up I'll go check out that other thing you suggested. Thank you very much. Fingers crossed this works!