Assasin Bugs

I get a lot of calls on the GardenLine where people are usually panicked about some hideous-looking orange and black spider on their plants. "What is it, and how do I kill it?" That's the normal inquiry. But you don't have to do anything. They are Assasin Bugs, and they are considered a true beneficial insect.

If you see a bug (or many of them) like the picture below on your shrub/flowering plant, just leave 'em be. They are there to help you, by eating aphids. Here's a great picture from one our listeners, who sent the digital picture wondering what it was and if it was hurting anything.

Normally, I see one or two of these amazing creatures at a time, but seldom have I ever seen this many in one concentrated setting. If you'll look real closely at the plant that the assassin bugs have gathered on, there are also plenty of tiny, yellow aphids on the stem of the plant. Again, that is what they are after.

There is an interesting dichotomy when it comes to assassin bugs versus aphids and a point of "no control". As you see by the picture, there are plenty of assassin bugs that could feast on the aphids quite effectively for that "true" beneficial control. However, when you see an assassin bug or two and there is a huge infestation of aphids, they likely won't be able to control them in that small of a number.

So, do you kill the assassin bug when you try to kill the aphids? NO! The easiest thing to do is pick off the assassin bug and move it to another plant, then treat for the aphids on the plant in question. Ladies, if you don't like handling bugs, then get your son or a neighbor's son to do the moving for you. They'll consider it a challenge and you know they love dealing with bugs. You should never kill assassin bugs just because your aphid infestation is really bad.

By the way, any liquid insecticide will work on the aphids, as will soapy water or even a water blast from the garden hose. If you use soapy water, please rinse the plant off with plain water a couple of hours later, so you don't suffocate the respiration process with a soapy film. And if a blast of water from the garden hose is more your speed, just remember the aphids will find their way back to the plant, usually in 48 hours.