Black Wind

The Black Wind is an annual migration of Ghoarz Flies from their habitat in the Baria Canyon to their mating grounds on the Cyranatic Islands. Due to the flies' near-microscopic size and their massive numbers, this migration appears visually to be a literal black wind that blows across Aquitilla every year; much folklore and superstition has stemmed from this bizarre sight and the agricultural threat posed by it.

History
Many mentions of the Black Wind have been found in numerous Oarspur sources, which is unsurprising given their ancestral location and the Wind's source. They implicate the migration in several natural disasters, including: They also believed that the Black Wind acted as a portent for events not tied to the natural world, almost univerally negatively. Those events that Oarspur texts indicate were foretold by (or perhaps caused by, depending on translation) the Wind include: Interestingly, recently-discovered documents seem to indicate (once again, depending on the translation) that for several consecutive years, immediately preceding the approximate time we now belive the Oarspur Catastrophe to have taken place, the Black Wind never left the Baria Canyon; it simply rose, circled for several days, and retreated. The relevant texts make it clear that these bizarre Winds were taken as warnings of a coming "great cataclysm"; modern biologists currently lack any explantion for the ghoarz flies' reported bizarre behavior, and no similar migrations have appeared in any other record.
 * The Great Famine of 1001 MEC
 * Several catastrophic earthquakes in the middle of the 11th century
 * A years-long string of unusually-powerful sandstorms that began in 1132 known as the Sky of Stone
 * The Barian Fires that occurred in 1140
 * Grand General Seretus's death in his Great City campaign
 * The Oarspur Revolts
 * The birth and death of several religious leaders

Modern Significance
While in the past, a Black Wind could severely damage crops in the regions they passed through, it was discovered in 3030 MEC that they could easily be repelled by installing supersonic repellants in farmland areas. After use of such repellants became widespread, the ghoarz flies' food sources became significantly reduced, radically reducing the number of flies that survived to make it to the Cyranic Islands and thus the number of offspring produced. While this was largely regarded as a blessing, in 3057 a group of environmental scientists demonstrated the flies' significance to a number of ecosystems and regulations were put in place to ensure their continued survival.

Currently, the Black Winds have a negligible impact on agriculture, due to specifically-designed forced migration routes and ample uncultivated food sources; instead, their main significance is on tourism and medicine. A number of helpful compunds have been found in fertile ghoarz flies, and the yearly migrations make gathering those compunds much easier than attempting to extract them at more inconvenient stages of the flies' life-cycle. Additionally, since air travel became commonplace, it's been more possible to observe the Winds up close and from above; now, Windwatching is a popular vacation activity in much the same way that murmuration-chasing was before the mass avian extinctions of 3211.