Onset of foraging and lifespan of Africanized honey bees (Apis mellifera) infected with different levels of Nosema ceranae spores in Neotropical Mexico

Nosema ceranae is a microsporidium pathogen widely spread around the world. Negative effects on foraging behavior and longevity of EHB colonies have been associated with this pathogen as well as possible population losses, but its effects have not been studied in tropical adapted honey bees. We studied the interaction between this pathogen and Africanized honey bees (AHB) in the Yucatan peninsula of Mexico where N. ceranae has only been detected since 2008. Non-infected and artificially infected workers with two different spore concentrations were introduced in observation hives to evaluate the onset and duration of foraging and longevity. The results showed precocious foraging, a reduction of the duration of foraging and a decrease in the longevity of infected bees compared with non-infected ones. However, the results indicate that although negative effects can be caused by N. ceranae in AHB, these were of a moderate magnitude compared with similar reports on EHB in temperate areas. Further research is necessary to evaluate the long-term effect of N. ceranae on AHBs in relation to colony dynamics to better understand the absence of significant colony losses associated with this pathogen in tropical and subtropical Mexico.