In matters of antennae, I imagine that surface area correlates with sensitivity. The male Hercules Moth Coscinocera Hercules must find his mate within a very short timeframe.
Adult females emerge from the chrysalis without mouth-parts, her 4-5 day life does not include feeding. After she emerges and her wings unfold and dry, she emits pheromones to attract a male. After mating, she will fly away, lay her eggs on the underside of the leaves of a food plant and die shortly after.