Aphids? If so, a soapy spray may help to eliminate. You should isolate this one and check anything nearby. If the soapy water doesn't work, I'd go 'big guns' and use an appropriate 'name brand' spray to eliminate them.

Good luck,

Bob

Looks like aphids to me as well. Spray with water every 3-5 days and in two weeks they should be gone. Aphids are such soft bodied that even a hand held sprayer is strong enough to do a number on them.

tj