These moths lay their eggs in the flower spikes of the Maca nut.
The larvae wipe out the crop. I got about 10 nuts last season.
There are some wonderful sprays to stop this, none which i will use. Angry stuff.
My question is, does BT spray affect all caterpillars and would it therefore kill maca moth larvae?
I’m gonna give it a shot but thought i’d run it by yuz.

BT will kill any caterpillar that eats it. thing is, if the larvae is inside the developing nut, will they end out eating it?

BG might be right, I don’t know how systemic BT is, if it is at all…

pain master said:

BG might be right, I don’t know how systemic BT is, if it is at all…

I don’t think it is systemic. The way it works say for brassicas is that you spray it on the leaves, the caterpillars eat the leaves thereby ingesting the BT which upsets their digestive system and they die. It is easily washed off so you need to reapply after rain. So I think the caterpillar would have to actually ingest the BT for it to be affective.

bluegreen said:

pain master said:

BG might be right, I don’t know how systemic BT is, if it is at all…

I don’t think it is systemic. The way it works say for brassicas is that you spray it on the leaves, the caterpillars eat the leaves thereby ingesting the BT which upsets their digestive system and they die. It is easily washed off so you need to reapply after rain. So I think the caterpillar would have to actually ingest the BT for it to be affective.

They don’t damage the nut, they eat the flower spike prior to fruit set.
I figure if i spray the flower spike and they eat the flower, they’ll die.
But will they die quickly enough to prevent the damage being done??
I dunno.

Longy said:

bluegreen said:

pain master said:

BG might be right, I don’t know how systemic BT is, if it is at all…

I don’t think it is systemic. The way it works say for brassicas is that you spray it on the leaves, the caterpillars eat the leaves thereby ingesting the BT which upsets their digestive system and they die. It is easily washed off so you need to reapply after rain. So I think the caterpillar would have to actually ingest the BT for it to be affective.

They don’t damage the nut, they eat the flower spike prior to fruit set.
I figure if i spray the flower spike and they eat the flower, they’ll die.
But will they die quickly enough to prevent the damage being done??
I dunno.

in that case I think it would kill the caterpillar and at the least interrupt the life cycle. The caterpillar doesn’t need to eat much of it so it might only eat one flower instead of multiple flowers?

bluegreen said:

pain master said:

BG might be right, I don’t know how systemic BT is, if it is at all…

I don’t think it is systemic. The way it works say for brassicas is that you spray it on the leaves, the caterpillars eat the leaves thereby ingesting the BT which upsets their digestive system and they die. It is easily washed off so you need to reapply after rain. So I think the caterpillar would have to actually ingest the BT for it to be affective.

That’s my understanding of it, too.

bluegreen said:

Longy said:

bluegreen said:

I don’t think it is systemic. The way it works say for brassicas is that you spray it on the leaves, the caterpillars eat the leaves thereby ingesting the BT which upsets their digestive system and they die. It is easily washed off so you need to reapply after rain. So I think the caterpillar would have to actually ingest the BT for it to be affective.

They don’t damage the nut, they eat the flower spike prior to fruit set.
I figure if i spray the flower spike and they eat the flower, they’ll die.
But will they die quickly enough to prevent the damage being done??
I dunno.

in that case I think it would kill the caterpillar and at the least interrupt the life cycle. The caterpillar doesn’t need to eat much of it so it might only eat one flower instead of multiple flowers?

Dr BG might have it here.

bluegreen said:

Longy said:

bluegreen said:

I don’t think it is systemic. The way it works say for brassicas is that you spray it on the leaves, the caterpillars eat the leaves thereby ingesting the BT which upsets their digestive system and they die. It is easily washed off so you need to reapply after rain. So I think the caterpillar would have to actually ingest the BT for it to be affective.

They don’t damage the nut, they eat the flower spike prior to fruit set.
I figure if i spray the flower spike and they eat the flower, they’ll die.
But will they die quickly enough to prevent the damage being done??
I dunno.

in that case I think it would kill the caterpillar and at the least interrupt the life cycle. The caterpillar doesn’t need to eat much of it so it might only eat one flower instead of multiple flowers?

Yeah i don’t know how quickly they eat, but you ho out one day and the lot is demolished, leaving a web through the spike. I reckon there are many eggs laid on each spike. There must be a whole mob of the moth which hits the tree at once, or the eggs were laid last season and don’t emerge until the flowers are ready. Anyway, i will spray and see what happens.