Pollination efficiency of Apis mellifera (Hymenoptera: Apidae) on Cosmos sulphureus (Asteraceae) capitula at Dang (Ngaoundéré, Cameroon)

To study the foraging activity of Apis mellifera (Hymenoptera: Apidae) on Cosmos sulphureus (Asteraceae) and to evaluate its impact fruits yields, C. capitula were observed Dang (Ngaoundéré, Cameroon) from September November 2016 August October 2017. Each year, observations made every day, 06.00 am 6.00 pm 540 divided in four treatments: 120 left free polliniation, protected insects ; 200 protected, then uncovered, exclusively visited by A. rebagged 100 uncovered without insect or any other organism visit. The behaviour capitula, pollination efficiency, fruiting rate, percentage mature achenes normal (well developed) evaluated. results show that among 10 species recorded after two seasons observation, was most represented with 95.57 % 1128 visits. This bee harvested intensely nectar pollen florets. akenes treatments unprotected significantly higher than those insects. Through efficiency a single capitule visit, increased 50.58 %, 14.37 40.52 respectively. installation colonies close fields is recommended increase honey as well production hive product.