Evaluation of Pesticide Effects on Honeybee Health and Colony Collapse: Findings from a Beekeeper Survey in the Beni Mellal-Khenifra Region, Morocco

Abstract

Since it first appeared in 2022, the phenomenon referred to as Colony Collapse Disorder (CCD) has affected several regions of Morocco to varying degrees. In order to assess the possible impact of pesticides on the appearance of this syndrome, we conducted a study aimed at evaluating the impact of pesticide use on the emergence of this syndrome through a year-long survey involving 160 beekeepers in the Beni Mellal–Khenifra Region (BKR) who also experienced an unprecedented desertion of hives during the same period. The majority of surveyed beekeepers practice mixed (45%) or migratory beekeeping (42%) and provide supplementary feeding (83.75%) to support their bees. Nearly 37.5% of the hives are located near crops treated with pesticides, exposing the bees to these chemicals. The results showed that the majority of beekeepers reported a cessation of queen laying (74.38%), high mortality rates among worker bees (81.25%), drones (65.63%), and queens (61.88%). Abnormal behaviors such as immobility with trembling (42.50%), reduced flights (47.50%), and disoriented navigation (28.75%) were also observed. Correlation analyses indicate that proximity to treated crops significantly increases the risk of queen laying cessation (Odds Ratio 6.0) and a reduction in waggle dances (Odds Ratio 2.41). Extended foraging flights show a borderline statistical significance (Odds Ratio 2.33), suggesting a disruption of natural food sources. These results highlight the potential impact of pesticides on colony health and bee behavior, pointing out the need to adapt beekeeping practices and implement protective measures against pesticides.