Lasius claviger
Abstract
Lasius claviger is a parasitic species of Lasius in the subgenus (Acanthomyops). It is one of the most successful Lasius social parasite in North America, being native to most U.S. states and Ontario, Canada. Workers are around 4-5 mm long, and queens are around 7-8 mm long. Workers are bright orange and smell like citronella, giving the nickname 'Citronella Ants', as the smell of citrus repels many predators. Queens are shiny compared to other Lasius parasites such as Lasius aphidicola, and can be black, dark brown, or reddish-brown in coloration.
Social parasitism is a method of colony founding in which a new queen, instead of founding her own colony, hijacks the colony of a related species in the same/similar genus, kills its queen, and uses the workers, referred to as 'host workers', to raise her own brood which will develop into Lasius claviger workers. Once all the host workers die out, the colony will be entirely composed of Lasius claviger workers.
Lasius claviger nuptial flights occur beginning in August and can continue as late as October, when I found my queen. Queens do not infiltrate host colonies right away and find a safe shelter to hibernate in alone for the winter. Once spring arrives, the queen emerges from hibernation and seeks out a host colony. Common target species may include Lasius neoniger, Lasius americanus, Lasius pallitarsis, Lasius crypticus, among others.
Once the queen encounters a host colony, she is attacked by the host workers. The queen is built for this, however, and her body is heavily armored with a thick exoskeleton meant to resist Lasius bites and formic acid spray. Parasitic queens infiltrate colonies utilizing chemical deception. Ants communicate using chemical signals known as pheromones. Each colony and each species has a distinct pheromone identifier to help them identify friend from foe. Since the queen is from a different colony and a different species, she is immediately identified as foreign and a threat to the colony. The queen uses this to her advantage, however. As the workers bite and swarm her, she is tasting their pheromones. Her body is capable of duplicating Lasius pheromones, yet she first needs samples. The biting workers rub a little of their pheromones onto her, and she also uses her muscular build and large mandibles to kill a couple workers. She grooms the dead workers' pheromones all over herself, coating herself in friendly messaging. This is where the wolf puts on the sheep's clothing. She engages workers to absorb their pheromones and then retreats if the workers become too aggressive or numerous. This continues until the workers recognize the queen as friendly and allow her into the nest. Once in the nest, the queen seeks out the queen of the host colony. Once she finds her, she attacks, using her killer-bred body to rip apart the host queen, grooming her queenly pheromones onto herself. After this, the workers are deceived into treating the Lasius claviger queen as their own queen. After a couple weeks, the new queen begins to lay her own eggs, slowly replacing the host workers with her own offspring. This can be replicated in captivity by collecting host workers and brood for the queen. Adult workers can be introduced, though it is better to give the queen callows (newly born, light-colored workers) that are less aggressive to minimize risk to the queen and calm down the queen's aggressive killer-temper.
Colonies generally stay exactly where their host colony was before. This means they live in a wide variety of biomes, as different host species have different preferences. Lasius neoniger prefers open fields and grassland while Lasius americanus prefers woodlands and forested areas. Since Lasius claviger preys on both, colonies will be found in both environments.
Many journals have documented polygyne (having multiple queens) in this species and related species such as Lasius interjectus, though it has not been thoroughly researched. While some populations of the species undoubtedly are polygynous, others may not be. It is uncertain as of yet.
The species is omnivorous, feeding on carbohydrates and proteins. Proteins can be obtained by scavenging for dead insects on the ground. Carbohydrates can be found in flower nectar and more importantly aphids. Lasius, especially Lasius (Acanthomyops) sp. are known for farming certain species of root aphids. The aphids produce a sweet, sugary nectar which the ants relish, and in return the ants protect the aphids from predators and move them to the most optimal locations for feeding and breeding. They are essentially dairy cows for the ants. While this has yet to be duplicated in captivity, most wild colonies of Lasius claviger have root aphid farms, though they can survive just fine without them.
Colonies grow large, much larger than their host colonies could ever dream. While a Lasius neoniger colony may reach 10,000 or 20,000 workers, Lasius claviger colonies can attain much higher numbers.
Resources
Journals:
AnthonyP163's Parasitic Lasius Journal - Ant Keeping Journals - Ants & Myrmecology Forum
AnthonyP163's Lasius sp. (Updated 2/27/25) - Ant Keeping Journals - Ants & Myrmecology Forum
AntBoi's Parasitic Lasius Journal - Ant Keeping Journals - Ants & Myrmecology Forum
Articles:
A Guide to Lasius Social Parasites | Stateside Ants
Update 1
October 24, 2024
In late October I found a lone Lasius claviger dealate on a sidewalk in central Sioux Falls. The temperature was cooling down, so there wasn't much I could do for hosts. I grabbed a few straggler Lasius workers from a local colony and soon after put them into hibernation. She didn't take very well to these hosts, and neither accepted each other in the long run. All hosts would end up dying during hibernation, yet the queen came out just fine.
March 22, 2025
In mid-March 2025 I took my colonies out of hibernation including the claviger queen. At this point the ground hadn't defrosted yet and there were still snow showerers occurring, so getting hosts right away was out of the question.
April 21, 2025
On one of the first days with a high above 70 F (~21 C) I collected around 200 host workers which I later identified as Lasius niger, an invasive species from Europe. It was far too early for the colony to have brood or callows, so adult workers would have to do. I introduced the queen to the workers in the outworld I gave them. As expected, the workers attacked the queen at first, yet the queen was adept at mimicking their pheromones. Within a couple hours of letting the workers attack her and then retreating, the workers accepted her, and she joined them in the Por Amor Cryptic Insert nest I gave them. This is one of the smoothest adult worker introductions I have witnessed with parasitic Lasius, and it may be due to the fact that Lasius niger, being from Europe, is not accustomed to Lasius claviger and hasn't evolved defense mechanisms against their deceptions yet.
June 3, 2025
Around 120 host workers ended up surviving. When collecting wild workers, many will die due to injury, stress, failure to adapt to captivity, and in this particular case, a CIA-esque martial artist Dwayne The Rock Johnson built killer queen ripping them to pieces. Around three weeks ago the queen began laying and the workers began craving protein. I fed them protein until the queen stopped laying eggs. Then the colony ate the eggs. After reading AnthonyP's Lasius journal I learned that Lasius do best when fed protein every day, so as soon as I began doing this the queen laid again. They have around 100 eggs in a pile as large as the queen herself. The hosts gorged themselves on the sunburst nectar and insects I gave them, and with all the hard parts of the founding stage out of the way, the colony's future is looking bright!
Edited by RushmoreAnts, June 2 2025 - 10:00 PM.
