EXAM #2 Flashcards
Reproduction
How is sex in collembola, diplura, and apterygotes?
Indirect sperm transfer. Male deposit sperm packet (spermatophore) on substrate, female picks up.
How is sex in pterygote insects?
Direct sperm transfer. Copulation, insertion ot aedeagous into female reproductive tract. In most insects, sperms delivered in a spermatophore and deposited in a copulatory pouch (genital chamber, vagina) or directly in a spermatheca.
What cues or mechanisms hook insects up?
Swarming
Leks (males defend territories with no resources)
Auditory (crickets (stridulate) and cicadas (tymbal)) -
Visual (fireflies - flash patterns are species specific)
Olfactory (moths - pheromones)
What are pheromones? What is the purpose for pheromone release?
Pheromones are chemicals released and received by conspecifics. These chemicals are released for different purposes such as sex, aggregation, defense, trail marking, etc.
Whats is courtship? How does it happen in insects?
Behavior that induces or enhances sexual receptivity. Courtship can be achieved by:
- Visual displays;
- Ritualized movement;
- Fight;
- Touching, stroking, and rubbing;
- Auditory signals;
- Pheromones;
Elaborate on the “runaway” evolution caused by female choice for male “ornaments”
Female choice for secondary male characterictics (horn, wing patterns, colors) over evolutionary time may drive exaggerated male carachteristics that do not otherwise contribute to fitness.
