Thrips and Neem Oil

[Chinghsi]

Hi, I have a persistent problem of Thrips on one of my Dendrobriums. They somehow survive the insecticide sprays, and re-emerge after a few weeks in the blooms. I do not wish to use too much insecticides, and have gotten a bottle of Neem oil. Wonder if it is alright for me to spray the Neem oil solution into the blooms as flowers are where the thrips hide in. Thanks!!

[camille1585]

From my experiences with thrips, they are very difficult to get rid of. I doubt the neem oil will do much (I don't use the stuff anyways). Thrips and mealies are the 2 critters that I only treat with chemicals. What type of insecticide were you using? For thrips you need a systemic, because they tend to hide deep in the plant, where contact insecticides can't kill them. If you do treat with a systemic, make sure to treat 2 or 3 times about 10-15 days apart, to get all the freshly hatched larvae. One that works well is a systemic with imidacloprid as the active ingredient. It's also has the advantage of being relatively "safe" to use in the house, compared to other systemics.
Good luck getting rid of the thrips!

[Chinghsi]

Originally Posted by camille1585

From my experiences with thrips, they are very difficult to get rid of. I doubt the neem oil will do much (I don't use the stuff anyways). Thrips and mealies are the 2 critters that I only treat with chemicals. What type of insecticide were you using? For thrips you need a systemic, because they tend to hide deep in the plant, where contact insecticides can't kill them. If you do treat with a systemic, make sure to treat 2 or 3 times about 10-15 days apart, to get all the freshly hatched larvae. One that works well is a systemic with imidacloprid as the active ingredient. It's also has the advantage of being relatively "safe" to use in the house, compared to other systemics.
Good luck getting rid of the thrips!

Hi, the first time I sprayed, I used Thiacloprid (baby bio house plant insecticide), and I used Imidacloprid (Confidor) on the second occasion. Yesterday, being the third time I am spraying, I rotated back to Thiacloprid. I think I did not eradicate the pest because I always thought I have killed all of them after each spray, and spray again only when I see them again. I think I will spray again in another week or so.

[Jerry Delaney]

Camille is absolutely right in using a systemic. None of the chemicals used in these post are ovacidal which means that even if you manage to kill most of the adult thrips when spraying, the eggs present will start a new population if only a single spraying is used. Also, thrip eggs take about 2 weeks to hatch in WARM weather which means it may take even longer in cool weather. You being in Singapore, maybe it doesn't make so much difference. Camille's recommendation of using a systemic should allow for enough carryover to get the next generation. Good luck!