Mating Walnut Flies: Summary
Let's summarize what's been covered.
- In walnut flies, both males and female mate multiple times.
- Copulations last either a short time (less than three minutes) or
a long time (more than ten minutes) -- why?
- When females are plentiful, males who mate with many females in a
short time fertilize the most eggs.
- When males outnumber females, males that continue mating for a long
time fertilize more eggs than those that move rapidly from female to
- This is in accordance with the predictions of "optimal foraging
theory:" when food patches (females) are far apart (search/travel
time is long), foragers (males) maximize their energy gain (egg fertilization
rate) by staying in each patch (with each female) for a relatively longer
- Researchers at the University of Arizona demonstrated this by manipulating
the sex ratios of walnut flies. Under male-biased sex ratios, copulations
were longer than under female-biased sex ratios.
End of Walnut Flies module.