Ecological Relationships and Interactions

Introduction

• Narrator's Sandbox Story: Introduction through personal story about antlions
  • Rediscovered sandbox with lots of tiny holes
  • Dad mentioned antlions
  • Dad loves insects

Antlions

• Appearance

  • Adult antlions resemble a less cool version of dragonflies
  • Larvae have mandibles and make sand pit traps

• Feeding Mechanism

  • Wait at the surface with mandibles showing
  • Trap ants by dragging them in, biting, and injecting digestive enzymes
  • Sometimes toss sand to help subdue prey

• Alternate Name

  • Often called ‘doodlebugs’

Ecological Relationships

• Predator-Prey Relationships

  • Antlions are predators; ants are prey
  • Population dynamics: Increase in ants -> Increase in antlions
  • Overpopulation of antlions -> Decrease in ants -> Decrease in antlions
  • These cycles often recur

• Antlions as Prey

  • Can be eaten by birds, becoming prey themselves

• Competition

  • Antlions compete for ants with other antlions and species (e.g., jumping spiders)
  • Plants compete for light (an abiotic factor)

Symbiotic Relationships

• Parasitism

  • One organism benefits, the other is harmed
  • Example: Dogs and fleas/hookworms
  • Parasite lives inside or on host, derives nutrients, and can harm host

• Mutualism

  • Both organisms benefit
  • Example: Acacia trees and acacia ants
    • Trees provide housing and sometimes nectar
    • Ants provide protection and eliminate plant competition

• Commensalism

  • One organism benefits, the other is neither helped nor harmed
  • Example: Barnacles on whales
    • Barnacles get access to food by attaching to whales
    • Whales are neither helped nor harmed

Importance of Ecological Relationships

• Interactions impact populations of species living together
• Human activities threatening one species can affect others

Conclusion

• Continuing discoveries in ecological relationships
• Reminder to stay curious