Worms in all guavas

[yogananda]

I would love to know how to prevent worms from taking over my guava tree. Help?

[rainbowgardener]

Knysna is in South Africa, right? I don't know that most of us here will be of much help to you. It would help to know more about what kind of "worm" you are battling. Does it eat the leaves or the fruit?

If it is a leaf eater, you could look around for Neem oil. The Neem tree is a tropical that originated in India, so should be available where you are. Sprayed on leaves, it specifically targets leaf eaters, because it has to be ingested. It is not a poison that kills the worms or anything on contact and it doesn't harm anything that isn't a leaf eater.

PS. Welcome to the Forum; glad you found us!

[yogananda]

Thanks for such a prompt response! No, not the leaves, but only the guavas are effected.

[rockhound]

If only the fruit are affected it must be the larva of a moth or beetle.
Edit: Here is a link, scroll down to "Pests and diseases" good luck.
https://www.hort.purdue.edu/newcrop/morton/guava.html

[Little Homestead]

Guavas...drool. Can't say I blame the critters for wanting to eat them!

I wonder if the tree is too big to cover with a large row cover type of fabric while the fruit is developing?

No experience with growing guava, so I don't know how big the tree is. So you may be laughing at my ignorance.

[The Helpful Gardener]

Couldn't find specific info for S. Africa but the culprit in much of our area that fits is the guava fruit worm, Argyresthia eugeniella.

Rock was spot on; this is a moth. My recommendation would be treatment just prior to the appearance of the moth with BT var. kurstaki, as this is the strain that is deadly to moths. You will have to ascertain the timing in your area; I might suggest talking to a governemnt agricultural service or extension agent to help you determine when that is

HG

[rockhound]

Apparently in Hawaii, guavas are treated to cause them to bear at different times of the year. I don't know how all this might apply to growing them in Africa but here's a link with more info than I wanted to know...
https://www.extento.hawaii.edu/kbase/crop/crops/i_guava.htm
By changing the suffix in the url, other fruit info is available too. Good luck in solving your problem, please tell us how you made out.

[floridahillnursery]

Hello, I have had a simular problem with strawberry guava here in Florida. They would look great, turn ripe Then BLAMMO I would open them up to find several little white worms inside. I found that blossom spray worked well for me. The fly lays an egg on the blossom, the worm enters the fruit when small only to emerge when the fruit is ripe. YUCK, I think I ate one once. BLAAA

[The Helpful Gardener]

Seems Rocky and FL Hill may be talking about the same thing; blossom spray or cytokinin is a plant hormone that causes the bloom to set fruit earlier. I am guessing but an earlier set might disrupt the timing for the fly to lay eggs and get them included in the fruit...

I still think talking to a local ag specialist is the best bet; we are trying to apply FL and HI info to SA...

HG