What are these bugs on my Hibiscus?

10 years ago

I've looked high and low - can't ID these nasty critters. I had two gorgeous Hibiscus in planters at my front door last summer, brought them in, and one started looking bad in Dec. - dropping leaves, leaves turning yellow etc. I found orange bugs (and later realized that there were black ones too) and assumed that they were spider mites. Sprayed with insecticidal soap to no avail and finally chucked the plant outside in the snow, as I didn't want the other one to get infected. (the insecticidal soap seemed to have no effect on these critters at all!) Fast forward two months - today I discovered that the other one is infected too. I got out my macro lens and took pics and those aren't spider mites! I don't know what they are though and need help identifying them and, I hope, KILLING them before they kill my second plant too. Please see the pictures: http://s1364.photobucket.com/user/duncanschreier/library/

Comments (3)

PaddyD
Original Author
10 years ago
Ok - figured out that they're thrips.

See: http://bugguide.net/node/view/216069/bgpage

The problem I'm having is that insecticidal soap doesn't seem to control them and Ontario has banned just about anything that might control them. Monterey Garden Insect Spray with Spinosad looks like it might work, but it's not available in Ontario. :( It is used on organic crops...available in the US, at Home Depot, if you order it online, but that doesn't help me, as they won't ship it over the border and my son, who is in the US this weekend, won't be there long enough to pick it up. It's nuts to spend $50/$60 to get it off eBay.

Anyone have any suggestions on dealing with these nasty little critters indoors? We're two months away from being able to put the plant outside, where I could do things like hose it off. It's too big to go in the shower.
jean001a
10 years ago
What are your prevailing daytime temps?
If warm enough to take outdoors even though only for a brief time, do so then bring it back indoors.
PaddyD
Original Author
10 years ago
Hi Jean, I'm in Toronto, where we've had a brutal winter that just doesn't seem to want to end. The last few days have been (just) above freezing, but not what I'd consider hibiscus temp! Definitely not an Oregon spring 'round here! (I lived in Corvallis for 7 years ;))

However, the good news is, that since I first posted I DRENCHED the plant with insecticidal soap and manually squashed every thrip I saw and since then, I've inspected it daily and haven't seen any more bugs! I will keep inspecting though - the life cycle of these little nuisances is several weeks.

It will go outside as soon as the weather is warm enough, but that may be a while. It's rather large and heavy and not something I can easily move in and out, so I'd prefer waiting until the nights are frost-free. That's generally not for another 6 weeks here.