Social Insects Flashcards
Characteristics and orders of eusocial insects
characterized by overlapping generations, cooporative brood care, and reproduction of labor. 5 orders of insects have eusocial species: Blattodea (termites), Thysanoptera (thrips), Hemiptera (aphids), Coleoptera (weevil), Hymenoptera (bees, ants, wasps).
How caste determination occurs in termites?
Caste structure is a result of developmental plasticity in
response to the environment.
• Social environment: pheromones, behaviors, colony
age/size.
• External environment: seasonal changes, predators,
food availability.
How does a termite know when another termite is dead?
- Increased fatty acid death cue
- Diminished chemical vital sign
How do termites communicate?
The termites communicate primarily through pheromones, which are perceived through chemoreceptors on the antennae.
Discuss the neurobiology behind chemoreception.
Each sensillum has multiple neurons with dendrites that bear the odor receptors. Interaction between the odor molecules and these receptors generate graded potentials. Strong enough graded potentials trigger action potentials.
What is the difference between termites and hymenopterans castes? What factors can trigger castes’ differentiation?
Termites have a high degree of developmental plasticity, unlike hymenopterans, whose castes are determined before pupation by genetics, pheromones, and nutrition. Once a larva pupates, its caste is set and cannot be changed.
Hemimetaboly allows for differentiation from worker to other castes. Differentiation is a result of social (pheromones, behavior, colony dynamics) or external environment (season, predators, food)
What three characteristics are needed to be considered eusocial?
- Cooperative brood care
- Overlapping generations
- Reproductive division of labor
Name three orders that have true eusocial insects.
- Blattodea
- Hymenoptera
- Thysanoptera
- Coleoptera
- Hemiptera
