Little Black Beetle Clusters In My Garden - Ask Extension
I have never seen these before and I don’t know if they are harmful or beneficial. They are on my green beans and giant sunflowers. They stay in sma...
Knowledgebase
Little Black Beetle Clusters In My Garden #711381
Asked August 09, 2020, 5:40 PM EDT
I have never seen these before and I don’t know if they are harmful or beneficial. They are on my green beans and giant sunflowers. They stay in small clusters (image) and also roam around. This is the 1st time I’ve planted sunflowers and I am wondering if they are linked. I wasn’t able to find anything on a beetle identification search. They don’t seem to be harming the plants (yet!)
County Oregon
Expert Response
The insects are green stink bug nymphs (youngsters). They have piercing-sucking mouthparts which can damage your bean pods.
During this heat, with temperatures 80F or above, applying any pesticide risks the plants' health. Even so, direct hits of insecticidal soap may be helpful against these nymphs if applied during the evening after temperatures have decreased.
If you have a limited number of the bugs, flicking them into soapy water is certainly safe for the plants, also very effective against these little suckers.
No one seems to be interested in writing about stink bugs on sunflowers. If the bugs are on the flower heads, they may damage the developing seeds. So, if the seeds are your reason for growing the plants, consider a periodic harsh water spray to blast the bugs off.
