End of season diminishing of food sources may challenge insects. This beetle is dealing with it on a Pteronia incana plant, an asbos (ash bush), late in September.
There is yellow-green to be seen at the stem-tip, new flowerhead growth for next week or so, as well as (fairly) open, yellow florets ready for today. Hairy bristles on developing fruit represents yesterday's flowers. This is proof of consistency in production on the plant's part; no shirking or malingering.
Insects play their part as well, by being numerous in most healthy veld environments and by getting hungry at regular, short intervals (Vlok and Schutte-Vlok, 2015; Manning, 2007; Manning and Goldblatt, 1997; iNaturalist).