Anteaters also eat ants, hence their name. Its nest lures ants to its opening, where the antlion awaits it with gaping jaws. Ants even fight each other!
Despite computer games that depict black ants attacking red ants, ants may very well compete with members of their own species, regardless of color. In fact, it is more likely that these ants will attack their own species since they get food from a common source. Leafcutter Ants. Hello, Cousin! The Queen and Her Subjects.
A colony of leafcutting ants is comprised of several castes. Most of these are female. Males, which are drones, hatch from unfertilized eggs and die shortly after mating with the queen.
Drones are considered lazy and inferior members of the colony, since all they do is eat and lie around until they are mature enough to mate. Most colonies have only one queen, but sometimes there is two or three, especially in large colonies. Ants, in general, have many enemies.
They are found in rainforest and deciduous forests as well as in open woodlands and scrub forests. Atta ants will also invade agricultural areas that supplant their forest habitats. Atta ants are often considered agricultural pests. However, they help maintain ecosystem health by aerating soil. They provide crucial nutrient redistribution in the forest through their discarding of spent fungus and their removal of their own waste material.
The ants are also a valued source of protein for other forest animals. During the day, leaf cutter ants leave the nest to forage. When a suitable food source is found, the ants will secrete chemicals from their poison gland sacs. These chemicals have two functions. Firstly they serve as a recruitment signal, attracting other ants from their colony to join them. Secondly these chemicals function as long-lasting orientation cues for the foraging trail.
Many chemical and behavioral details of the ants' poison gland are not well understood. However, we do know that the deposition and potency of these chemicals depends on both the quality of food and the need of the colony's fungus for new vegetation. When an ant finds a high quality food source, they summon other nearby ants to join them by stridulating, or rubbing their body parts together to make a vibrating sound.
Tender leaves, higher in sugar, are usually deemed the most desirable, as opposed to tough, thick leaves. The more desirable the food source, the more ants tend to stridulate. When a leaf carrying ant is ready to take a leaf fragment back to the nest, she will stridulate, attracting a minim worker to join her on the journey home. These minim workers ride on the leaf fragments, and defend the leaf carriers from attack by parasitic phorid flies, that try to lay eggs on the leaf carriers' bodies.
Minim ants also perform another job while riding on the leaf fragment. It is thought that minim workers inspect and clean leaf fragments, so they are free of any harmful bacteria or fungi. Leaf Cutter Ants subscribe to a caste system, where ants carry out specific jobs based on the size of their head. Where ants are abundant, it is almost impossible to establish natural pine reproduction. In such sites, young pine seedlings often are destroyed within a few days unless the ants are controlled before planting.
Because leaf cutting ants only eat the fungus they cultivate, they do not respond well to most conventional ant baits, including sugar- or oil-based baits.
Leaf cutter workers can be distinguished from other ants by the three pairs of prominent spines on their back thorax and one pair of spines on the back of the head. Another species of leaf cutting ant found in Texas, Acromyrmex versicolor , may be found in the far west, drier parts of the state.
Acromyrmex is a true desert ant, and can be distinguished from the Texas leaf cutting ant by having more than three pairs of short spines on the thorax and by the bumpy upper surface of the abdomen gaster. Leaf cutting ant colonies comprise many mounds. Image by Josh Blanek. The Texas leaf cutting ant queen rules the colony from her underground chambers.
Colonies may have as many as four or five fertile queens, each of which continually produce eggs. Most larvae develop into sterile female workers ants; however, in the spring, some of the larvae develop into winged males and females. These reproductive ants can number into the thousands. They are distinct from worker ants, being several times larger, that they are often not recognized as the same species. They are dark, rusty brown with have long, smoky brown-black wings.
Females can be distinguished from males by their larger heads. Mating flights of Texas leaf cutting ant reproductives take place on clear, moonless nights during April, May and June. In areas of higher rainfall, swarms can occur at any time during the spring; however, to more arid areas swarms invariably occur after a heavy rainfall. Prior to her nuptial flight the virgin queen stores a small portion of the fungus garden in a small cavity inside her mouth.
After mating the winged males die, while mated queens drop to the ground, lose their wings and attempt to establish small nests beneath the soil. After digging a small gallery in the soil, the queen takes the fungus wad from her mouth and begins to culture it as food for her first eggs. Initially the fungus is nourished by fecal material. Approximately 90 percent of this first brood will be eaten by the queen.
This polymorphism stems from both environmentally and genetically controlled factors. The obligate co-dependence between the leaf-cutter ant and their fungal crop makes both species precariously susceptible to contamination events with other nearby microbes. How is this relationship maintained when decaying leaves make such a great feast for a multitude of microbes? Ants are meticulous cleaners when it comes to caring for their crop.
They remove debris and pest-infested areas in a process called weeding. Some ants even use separate areas within the nest as a waste dump to keep debris and contaminated portions of leaves or fungus away from their prized fungus gardens. Figure 3. While leaf-cutter ants like to maintain a tidy abode, they also populate their fungal gardens with fecal droplets. Ants also secrete phenylacetic acid and short-chain fatty acids, both with antimicrobial properties.
When the ants tend to their gardens, these secreted molecules are conveniently deposited to keep their crop pest free. While ants produce molecules to keep pests and invading microbes at bay, they also enlist several microbial partners to defend against pests.
The most well-studied example are the actinobacteria.
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