Ant colonies exhibit different properties as some are monomorphic while a few are polymorphic depending on the inherent characteristics and impact of the environment.
Are Black Crazy Ants Polymorphic? Black crazy ants are not polymorphic, as all of their workers look alike due to their similar size, shape, and function. They are monomorphic and have a single node, broad base, round acidopore, long legs, and wedge-shaped petiole. All of them lack stinger and bite for their defense.
Black crazy ants, also known as Paratrechina longicornis have smaller colonies and consist of multiple queens, but most of their members appear similar to each other except for queens and males.
Similar physical features affect their competitive ability and colony survival because all members have the same capability, and no one is stronger or expert in their work.
Why are black crazy ants not polymorphic?
There are different biological terms for the morphological differentiation of two organisms, like monomorphic, dimorphic, and polymorphic.
Monomorphic and dimorphic means all organisms in a colony are similar or appear in two different shapes and sizes.
In addition, polymorphic ants mean that there are different types of insects in a single colony with varying appearances.
The term ‘polymorphism’ in a colony means the workers have different appearances because every colony contains a queen, males, and females.
Accordingly, black crazy ants are monomorphic because all workers in their colony appear similar and perform identical functions in and out of the nest.
Moreover, their colonies are smaller and based on a few hundred members, so the division of labor is not considered essential, and it changes with age only.
They lack stingers and use the poison to defeat their enemy by spraying formic acid onto their body. Moreover, it can help avail chance to escape a predator’s grip.
They have a wedge-shaped petiole, a single node located between the gaster and propodeum, and consist of a broad base.
Moreover, all female workers have longer legs that help them forage for food and hunt their prey.
In addition, they have an acidpore of the same size, which is a small opening for releasing formic acid onto the prey body to cause a painful sensation. A fringe of bristles surrounds this acidopore.
All these wingless workers have an equal body size of 2.6mm (0.1 inches) on average, which is considered too small compared to other species.
So, the physical similarities of workers in black crazy ant colonies make them monomorphic and different from the carpenter and pharaoh species.
Are black crazy ants genetically identical?
Black crazy ant colony consists of genetically different organisms because it comprises reproductive males and females in addition to sterile females.
All these three castes are genetically different because new queens are clones of their mothers while males have genetic makeup similar to their fathers.
However, the sterile workers have a mixture of genes from male and female, and all workers are genetically identical because their parents are the same.
Some external factors can alter their appearance and introduce polymorphism in these workers, but their genetic makeup is almost identical.
A larger population inside a colony consists of sterile workers that cannot transfer their genetic makeup to the next generations due to their non-reproductive nature.
Furthermore, they are produced to perform nest activities and take care of the reproductive members and newly born eggs or larvae.
What types of ants are polymorphic?
Different species of ants exhibit different properties, as some are polymorphic, while a few are monomorphic when their workers perform the same roles in a colony.
There is no concept of minor and significant sterile workers in the monomorphic colonies because they all have the same body shape and size.
Moreover, the carpenter and harvester ants are considered polymorphic because tasks are divided between workers as larger ones protect the colony, while smaller clean nests and forage for food.
The pharaoh ants are also polymorphic insects as they have larger colonies based on thousands of members and hundreds of queens, and their worker’s body size ranges between 1.5 to 2mm.
The polymorphic red imported ants are 1.58 to 6mm long and appear red or yellowish with a different color of gaster as some have brown while a few have black gaster.
However, pavement and black crazy ants are monomorphic because all their sterile females have the same body length and shape.
The monomorphic insects show unnoticeable variations in their morphology, making it difficult to differentiate one worker from another.
Furthermore, some species are dimorphic, belonging to Pheidole or Cephalotes, as their workers are divided into two categories based on their size.
How does polymorphism affect an ant colony?
The difference in size and shape of workers determines their efficiency in performing tasks, the colony’s survival rate, and the queens’ reproduction rate.
It directly impacts the colony’s fitness as larger ones can protect the colony from predators and other animals by fighting for defense.
In the same way, the minor workers collect food, chew or break it into smaller parts for easier consumption and feed to other colony members as they have to take care of their nutrition.
Moreover, it is essential to provide adequate nourishment to young ones for better development, as compromised growth of larvae and pupae affect their efficiency in performing tasks.
The queens need food to be able to mate and produce eggs to ensure continuity of life, as the adult workers die after the completion of their lifespan.
The competitive ability of black crazy ants is lesser than the carpenter ants because carpenter workers have a division of labor, and every member performs their own task.
Furthermore, honeypot ants have special larger workers that perform only one task of storing food and feeding to the weak members of the colony to make them replete.
What factors determine polymorphism in ants?
Different factors are associated with polymorphism in ants, including internal factors related to the colony, like social interaction and the development of larvae.
Some heredity or genetic factors are most prominent in determining the size of workers as they get genes from their parents and look like them.
Moreover, external factors contribute to introducing polymorphism, like external temperature, enemies, and food availability affect larvae development.
The size of the colony affects the fate of workers as a larger colony has a division of labor and exhibit polymorphism, while the smaller ones have no such concept of variations.
The larger colonies have multiple queens that produce morphologically different workers as they mate with different males.
Furthermore, evolution also plays a role in bringing variations in the size of these insects that can occur due to changes in habitat structure or enemy environment.
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