An excerpt from the environmental audio dispatch 'Voces de la Selva' reports on native bee conservation in Mexico's southern rainforests:
"While European honeybees often struggle in the humid understory of the Lacandon Jungle, native stingless bees (*Melipona beecheii*) thrive within multi-layered agroforestry plots. To safeguard these fragile colonies against invasive phorid flies without resorting to chemical pesticides, research teams seal the internal joints of the wooden nesting boxes with a blended paste of crushed copal resin and fine river sediment. This natural formulation hardens rapidly, effectively blocking fly larvae while preserving an optimal internal humidity level of roughly seventy-five percent. In contrast, local producers previously attempted to deter pests by burning dried brush near the hives, a technique that inadvertently raised hive temperatures and lowered annual honey production by thirty percent."
According to the audio report, what specific method do researchers use to protect the native bee hives from invasive flies?
- ABurning dried brush in adjacent plots to deter pests through smoke accumulation
- BApplying low-toxicity chemical pesticides along the external canopy layer
- Sealing the interior joints of nesting boxes with a paste of crushed copal resin and river sedimentAnswer
- DIntroducing European honeybees to outcompete fly populations in the humid understory