Amegilla sp. (Hymenoptera: Apidae) Visitors to Cotton (Gossypium hirsutum, Malvaceae) Flowers and Their Role in Crop Pollination at Djoumassi (North, Cameroon)

Abstract

Aims: To evaluate the impact of a single flower visit of Amegilla sp. on the production of Gossypium hirsutum.
 Study Design: A randomized complete block design was used in a split plot scheme of 437 m2 delimited and divided into eight subplots, each measuring 8*4.5 m2.
 Place and Duration of Study: Locality of Djoumassi, Benoue Division, in the city of Garoua, the North Region of Cameroon from June through October 2018 and 2019.
 Methodology: The experiments were carried out on 540 flowers labeled at bud stage and divided in four treatments: two differentiated according to the presence or absence flowers protection regarding insect visits; the third protected and uncovered when flowers were opened, to allow Amegilla sp. visits and the fourth with the flowers protected, uncovered when they were opened, then rebagged without any visit.
 Results: Among 21 insect species recorded on G. hirsutum flowers, Amegilla sp. ranked second and harvested nectar and pollen. Throughout the pollination efficiency of a single flower visit, Amegilla sp. provoked a significant increase of the fruiting rate, the mean number of seeds per boll and the percentage of normal seeds by 14.89%, 12.93% and 7.01% respectively.
 Conclusion: The conservation and installation of Amegilla sp. nests close to G. hirsutum fields is recommended to improve its boll production and seed quality.