Help! Aphid infestation
 

Hey alls,

I have a greenhouse shelf from Target that has two levels of grow lights on it.

I normally do some kind of watering in the tent every day so it gets regular airflow by being opened up and having stuff moved around, but for the most part it is all set up to go automatically, so when I left town for a week and asked a housemate to look after my houseplant collection, I told her she didn't need to bother with the greenhouse.

Well, I came back today and first thing I noticed was an aphid infestation on one of my kohleria plants!!! It is a sprawling plant and is in a steady growth phase, so leaves are brushing up against other plants.

What can I do about this? I'm hoping to avoid something drastic like neem oil, but I do have hydro peroxide, alcohol, sulpher...

I am beside myself--I've been doing so great with my plant collection, lately!

Small infestations a few days of hand squishing works. Larger infestations I have some organic insecticidal soap but it has caused damage on some of the flowers and new growths of my orchids when I’ve had to use it.

Le sigh. Insecticidal soap it is. I just trimmed back the leaves I spotted the little sob's on, but there were so many of them...

How did this happen?

Hello Zinda!
Aphids are famous for going from "not noticed" to "swarms" all of a sudden, especially this time of year.
Insecticidal soap is probably your least-toxic option. Peroxide, alcohol, sulfur and such are more likely to damage the plant and less likely to kill the aphids. These products are all "chemicals" too.
Don't let the word "insecticidal" spook you. This is just soap that has been especially formulated to NOT damage the plant. Look for a product that has "potassium salts of fatty acids" as the active ingredient. Again, this is just soap, by its chemical name. Dish soap has been specially formulated to clean dishes, and is more likely to damage the plant. "Insecticidal Soap" is made for plants. It kills bugs on contact, there is no residual or systemic effect. It is just soap and water, but made to use on plants. It kills aphids.
Follow the label directions. You'll need to thoroughly spray the whole plant. After about half an hour you can rinse it off with plain water, this also helps lessen the chance of phytotoxicity. You'll need to repeat this 2-3 times a week for several weeks, then give it a rest but keep a close eye out for more bugs. You may need to continue to spot treat for awhile. Also keep an eye on your other plants. It's easier when you catch it early on, and now you know what to look for.
Here's a link to an article with a good explanation as to why you should use "insecticidal soap" instead of "Grandma's home remedy dish soap formula"
Control Houseplant Insect Pests Safely With Insecticidal Soap | News

:waving

A number of aphid species can reproduce asexually. Even in the case of sexual species, it just takes one pregnant winged female sneaking in. I usually don’t notice them either until their numbers are high.

Thanks, guys! I'll spray tomorrow when I can take everything outside and let the sun, wind and maybe rain help out a bit.

I'm more concerned about my carnivores at this point--I believe pretty much any chemical treatment can kill sundews and butterworts...my babies...