Mating frenzies, sperm hoards, and brood raids: The life of a fire ant queen - Walter R. Tschinkel

Summary

In June, following heavy rain, fire ants embark on a nuptial flight where males and females mate in a lethal frenzy. The successful female, now a queen, starts a colony alone, laying eggs and nurturing the first workers. As the colony grows, it faces brood raids but can usurp others, expanding its workforce. The colony's lifecycle involves producing workers and, once large enough, fertile alates for annual mating flights. The ants work together, defending and expanding their nest, forming living rafts in floods. After about 8 years, the queen's reign ends, but her genetic legacy continues.

Takeaways

• 🌧️ After heavy rainfall in June, fire ants (Solenopsis invicta) engage in a nuptial flight, a critical event for mating and colony establishment.
• 🐜 The nuptial flight is a high-risk period for alates, the reproductive ants, as they face predators and the challenge of mating, which is often fatal for males.
• 👑 A mated female ant becomes a queen, tasked with founding a new colony by herself, starting with laying about ten eggs per day.
• 🏰 The queen selects a suitable location, often disturbed soil, to build her nest, signifying her status by breaking off her wings.
• 🍂 In the early stages, the queen relies on unfertilized eggs for sustenance, losing significant body weight while waiting for her first workers to mature.
• 🐛 The first generation of worker ants emerges after about 20 days, taking over foraging and caring for the queen and brood.
• 🤝 Neighboring colonies can engage in brood-raiding, where workers steal offspring from other nests, leading to conflicts and sometimes the usurpation of colonies.
• 🔄 A defeated queen may join a rival colony, fighting to become the new reigning queen if successful.
• 🌿 Once the colony's population surpasses 23,000, it transitions to producing fertile alates, ensuring the continuation of the species through annual mating flights.
• 🌱 The colony operates as a super-organism, with ants of different ages performing various roles, from feeding the queen to defending the nest.
• ⏳ The life cycle of a fire ant colony typically lasts about 8 years, after which the queen's sperm supply is depleted, and the colony declines or is taken over.

Q & A

What is the nuptial flight of fire ants?

The nuptial flight is a mating event where thousands of reproduction-capable male and female fire ants, called alates, take wing for the first and last time.

Why is the nuptial flight a one-time event for fire ants?

The nuptial flight is a one-time event because even successful males who manage to avoid predators will die after mating, and for mated females, their wings are broken off to establish their status as a queen and start a new colony.

How does a new queen ant start a colony?

A new queen ant starts a colony by descending to the ground, searching for a suitable spot with loose soil, breaking off her wings, digging a tunnel ending in a chamber, and laying her eggs.

What is the role of the first generation of worker ants in a new colony?

The first generation of worker ants in a new colony is responsible for foraging for food and sustaining their queen, who has lost half her body weight by nourishing herself and her brood with unfertilized eggs.

What is brood-raiding and how does it affect a new colony?

Brood-raiding is a phenomenon where workers from neighboring nests steal offspring from a queen's colony. It can lead to the loss of the entire brood supply and the abandonment of the queen by her surviving daughters.

How does a queen ant usurp another colony?

A queen ant usurps another colony by following the raiding trail to the winning nest, fighting off other losing queens and the defending nest's workers, and taking over the brood pile.

What is the primary goal of a fire ant colony?

The primary goal of a fire ant colony is reproduction, which is achieved by producing fertile alate males and females every spring to continue the cycle of mating and colony establishment.

How does a fire ant colony function as a super-organism?

A fire ant colony functions as a super-organism through the division of labor among ants, with younger ants feeding the queen and tending to the brood, and older workers foraging for food and defending the nest.

What happens to a fire ant colony after heavy rainfalls?

After heavy rainfalls, fire ant colonies produce alate ants that take to the skies for mating, and the colony comes together to use the wet dirt to expand their nest.

How does a fire ant colony respond to a disastrous flood?

In response to a disastrous flood, a fire ant colony bands together into a massive living raft, carrying their queen to safety.

What is the typical lifespan of a fire ant queen and her colony?

The typical lifespan of a fire ant queen is about 8 years, after which she runs out of sperm and can no longer replace dying workers, leading to the decline and eventual takeover of the colony by a neighboring colony.