When does subterranean swarming typically start?

Subterranean swarming typically occurs within one year after a new colony starts. This timing is crucial because it aligns with the natural life cycle of many subterranean insects, particularly termites. When a colony becomes well-established, it will reach a population density that triggers the reproduction phase, leading to the formation of new reproductive individuals. These winged termites, often called alates, emerge from their nests to swarm, seeking to establish new colonies.

The other options do not accurately reflect the biological patterns observed in subterranean insects. Swarming immediately after eggs are laid would not allow time for the necessary development and maturation of the colony. Swarming in the fall or at the start of winter contradicts the life cycle timing as swarming is typically associated with warmer conditions in spring or early summer when environmental factors are favorable for new colony establishment. Thus, the option indicating that swarming occurs within one year of the establishment of a colony is aligned with observed behaviors and the lifecycle patterns of these organisms.