What is this yellow/black bug on my sunflowers? Home › Forums › Flower-Garden Questions › Annuals and Perennials › What is this yellow/black bug on my sunflowers? This topic contains 0 replies, has 1 voice, and was last updated by Anonymous 8 years, 2 months ago. Viewing 1 post (of 1 total) Author Posts August 27, 2008 at 7:33 pm #28393 Anonymous Here is the flickr picture (beautiful picture btw). I have hundreds of these bugs!! Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic.