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View Diary: This week in science: billions and billionaires (107 comments)

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  •  Fruit Flies Medicate Offspring... (4+ / 0-)

    After Seeing Parasites, in this week's journal Science.  

    In brief, fruit flies avoid parasitic wasps by laying their eggs in alcohol soaked food, but only when they SEE female wasps, the ones that lay parasitic eggs on fruit fly larvae.  

    A team at Emory University studied the egg laying behavior of D. melanogaster around parasitic wasps.  D. melanogaster prefers to lay eggs in decomposing fruit;  the alcohol content of said fruit has selected for fruit flies that can basically drink you under the table, plus it protects the larvae from becoming wasp food. While they prefer to lay eggs in dishes with alcohol content of 3%, they chose a dish with 6% to 15% alcohol over no alcohol when female parasitic wasps were present.  This, even though high concentrations of alcohol make the poor little larvae work a lot harder. But it keeps the wasps away.

    They don't do this when male parasitic wasps or wasp larvae are present.

    Blind fruit flies (there is every variety under the sun) don't exhibit this behavior when female wasps are present. So this is a visual trigger.

    Fruit flies with anosmia (defective sense of smell) still respond to the visible presence of female wasps with this alcohol preference.  So smell doesn't seem to be a factor.  Don't ask me how they locate the alcohol.  Maybe they taste it with their feet.

    The alcohol-seeking behavior lasts long after the wasps are gone (for days).  But the researchers have mutant fruit flies that lack long-term memory and switch the alcohol preference off once the female wasps are gone.  

    •  Rotten bananas have a distinctive appearence (0+ / 0-)

      compared to fresh or unripe ones.

      The path of the righteous man is beset on all sides by the inequities of the selfish and the tyranny of evil men.

      by xxdr zombiexx on Sat Mar 02, 2013 at 08:51:52 AM PST

      [ Parent ]

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