Social Insects

Question 1

What are the types of sociality in insects? (5) Give an example of each

Answer 1

1. solitary - spider hawk wasp
2. communal - wasps and bees (digger bees)
3. quasisocial - Euglossine bees
4. semisocial - Halictid bees
5. eusocial - some wasps and most bees, all ants and termites

Question 2

What four criteria must be met for a species to be eusocial?

Answer 2

• common nest site
• cooperative brood care
• reproductive castes/ reproductive division of labor
• overlapping generations

Question 3

What are the advantages of eusociality?

Answer 3

• parallel vs. serial operations (fewer mistakes are made when labor is divided among specialists)
• concentration of energy through sheer numbers ( economy of scale) (contruct and maintain nests, defend colony, retrieve food and other resources)
• caste differentiation allows for divisions of labor

Question 4

What are the disadvantages of eusociality?

Answer 4

• most individuals sacrifice their ability to reproduce
• colony attracts more predators
• large numbers make them more susceptible to picking up diseases

Question 5

What is the haplodiploid theory of eusociality?

Answer 5

females are diploid and males are haploid. the queeen can control sex ratio by selectively fertilizing eggs.
- it is more effective to aid the queen in producing more sisters than in self reproduction ( own offspring would be less closely related than sisters who are related by 75% as opposed to 50%)

Question 6

What are some communications used by eusocial insects?

Answer 6

• alarm pheromone - nest defense cause recruits workers en masse
• nest identification/nestmate recognition
• queen pheromones 0 regulate activity + suppress reproduction in workers
• propaganda substance - some ant species raid nests of conspecifics. invading queen produces alarm pheromone to drive workers out –> sits on the host queen for 3 days to acumulate her scent and then kills her so that when workers return they will care for raiding queens brood.