Susceptibility of Apis mellifera to Bacillus thuringiensis Berliner, nuclear multiple polyhedrosis virus, azadirachtin, pyrethrins, and abamectin

In recent years, the density of Apis mellifera L. has declined due to a phenomenon known as Colony Collapse Disorder. The irrational use of pesticides is considered one of the causes. However, the primary focus in this area is on synthetic insecticides. Hence, this research aimed to assess the toxicity of commercial doses of Bacillus thuringiensis Berliner, nuclear multiple polyhedrosis virus (NPVs), azadirachtin, pyrethrins, and abamectin against A. mellifera . In contact and ingestion bioassays, the highest toxicity was achieved with abamectin (100% mortality). Pyrethrins exhibited a mortality rate of 53.2% whereas NPVs did not result in any mortality. Although untreated bees preferred control over treated diet in repellency bioassays, no significant differences between treatments were observed. We concluded that abamectin and pyrethrins are the most harmful to bees by contact and ingestion toxicity.