A strategy for protecting wildlife nesting sites from Africanized honey bees

Since 1994, agricultural producers in the Everglades Agricultural Area (EAA) of south Florida have supported a program using barn owls (Tyto alba) as a sustainable means of rodent control.  Based on the placement of man-made... [ view full abstract ]

Since 1994, agricultural producers in the Everglades Agricultural Area (EAA) of south Florida have supported a program using barn owls (Tyto alba) as a sustainable means of rodent control.  Based on the placement of man-made nesting boxes on field perimeters, the project has successfully enhanced barn owl populations, with over 90% of nesting boxes ultimately housing nesting or roosting.  However, beginning in 2005, honey bees were observed to have colonized some of the nesting boxes, using them as hives.  By the year 2012, two out of every three boxes the eastern EAA were taken over by the bees, which were identified as invasive Africanized honey bees (AHB).  A hybridized form of European (EHB) and African honey bees, AHBs swarm much more frequently than EHBs, and are also less rigorous in selection of potential hive sites.  AHBs also respond to perceived threats to their hives in much greater numbers and for much greater distances than EHBs, posing a legitimate threat to humans and wildlife species that may unknowingly  venture too close.  To deal with this threat, a replicated field study was implemented to test the effectiveness of a push-pull IPM strategy, monitoring 150 boxes over a two year period.  Using an encapsulated permethrin insecticide inside the nesting box to prevent AHB scouts from identifying boxes as potential hive sites (push), along with a pheromone-baited swarm trap in the vicinity of the nesting box to attract the bees (pull), this strategy has proven very effective in protecting nesting box take-over by AHBs.  The permethrin insecticide, with extremely low mammalian and avian toxicity, has no detectable negative effects on the birds, and may even have benefits, as in reducing parasitism by hemophagous insects such as mosquitoes and lice.  Additionally, wild AHB swarms attracted to swarm traps may be easily removed for safety reasons and perhaps even converted to commercial quality hives by re-queening with European honey bee queens.  This strategy has also proven beneficial in other situations, such as that faced by macaws and other cavity nesters in the Brazilian rainforests.