Eusocieties Strong Interdependence Within a Population
Eusocieties Objectives
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Provide examples of eusocial species, including the roles individuals play in these societies.
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List representative species in Order Hymenoptera, including shared structures, social behaviors, and ecosystem roles.
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Describe characteristics of ant eusocieties, including roles and interactions.
These worker bees are foraging for food. Other worker bees, the queen, and male drones back at the hive are dependent on these bees returning with food. Strongly interdependent societies are called eusocieties, or even super-organisms.
This video introduces the concept of eusocial behaviors.
Breeding colonies of naked mole rat eusocieties have been established in some zoos and research facilities. This one is located at the Oregon Zoo in Portland Oregon.
Some of the most elaborate examples of eusocieties are insect species in Order Hymenoptera.
Hymenoptera
Our relationship with the ants, wasps, bees, and termites in Order Hymenoptera is often adversarial.
Most people know not to interact with these wasps. We are well aware of the possibility of getting stung, and also the damage some species can do to crops and structures.
It is easy to overlook the significance of these 15,000+ species.
We’ll start with a brief look at classification, to contextualize where the hymenopterans fit with other insects.
This video focuses on the Hymenoptera and their shared characteristics.
Some of the best stories about animals, including the hymenopteran, are found in highly illustrated “gift books.”
It includes the valuable roles ants can play in ecosystems, including spreading seeds and fertilizing soils.
Hymenopterans can build structures out of different materials, depending on the species.
Wasps
Paper wasps can chew up leaves and stems to make a pulp building material they use to construct waterproof, strong, and lightweight structures.
Hornets
These hornets also build a paper structure, but the inner cells are protected with layers of outer material so they do not need to be under cover.
Termites that build large mounds use soil and many generations of labor. The mounds can outlive a colony, and in some cases new termites move in and rebuild a mound for their own use.
Some of the wasp species eat a wide variety of foods. These wasps are feeding on Asian pears that have fallen to the ground. This is one of the points where it’s worth reconsidering whether the video is worth the risk.
Here a related species is consuming a dead snake. These are often the wasps that will carry off your food when you are having a picnic and have the common name of “meat bees” (they’re not bees).
Lesley has her own adversarial relationship with this species of “yellowjacket” ground-dwelling wasp. It is easy to step on their entrances when walking off trail, and a single wasp can sting repeatedly. After being stung on three different days over a week’s time, Lesley developed an allergy to the venom. After being stung, it is probably a better idea to not try it again right away :).
Ant Eusocieties
Many ant species form eusocieties. This video introduces ants with a range of artifacts.
Ants have some of the most intricate behaviors seen within invertebrate species. This includes coordinated efforts like these ants attempting to bridge a gap between branches.
Ant species have incredibly varied diets. Leafcutter ants harvest and carry leaves back to their tunnels. The leaves are used as compost for the fungal colonies they grow underground. They are so efficient at foraging, a single colony’s underground tunnels can reach 30 meters in diameter.
A single ant can carry a leaf many times its body weight. The cuts seen on the leaves are made with powerful mandibles that also deter predators.
Honeydew is sugar water secreted by aphids that feed on plant sap. Different species of “honeydew ants” farm these aphids like mini cows. The ants protect the aphids, herd them to keep them from straying, and consume the honeydew the aphids produce.
This close association is an example of symbiosis. The honeydew ants benefit because they get nutrients, and the aphids benefit because the ants drive off predators like lady beetles. Which type of symbiosis is this?
You can check your answer in the symbiosis section.
Maintaining ants for study in an “ant farm” enclosure is popular because ants can be quite active and some species will dig tunnels in a provided substrate.
This video demonstrates the set-up for one of the most popular ant enclosures.
Ants, and their relatives termites, often appear uninvited to human enclosures.
Typically we see ants moving from one point to another as they are in the photo. They follow chemical paths deposited by other ants.
Ants do spend time eating, resting and sleeping, we just don’t typical see it occurring. Note the tactile communication between ants in this video.
This is the end of the Societies Guide. Material from this online guide and corresponding lecture, as well as the previous Fitness Guide, is assessed on the weekly quiz.
Check your knowledge. Can you:
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provide examples of eusocial species, including the roles individuals play in these societies?
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list representative species in Order Hymenoptera, including shared structures, social behaviors, and ecosystem roles?
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describe characteristics of ant eusocieties, including roles and interactions?
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Societies Lecture Guide Contents
The material from this guide and corresponding lecture is assessed on the weekly quiz.
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