Imagine that varroa mites (a pest for honey bees) develop a resistance to acaric
ID: 167101 • Letter: I
Question
Imagine that varroa mites (a pest for honey bees) develop a resistance to acaricides (a pesticide that kills arachinds) Further imagine that this resistance is due to a mutation in an autosomal gene and is recessive suppose you have a lazy beekeeper who does not check her hives regularly, but because she knows mites are present, still treats them each winter with an acaricide when bees are sedentary and notequalto mites can be introduced from outside the colony. After three years, she finds that the number of varroa mites in each hive is far greater that what it was previously. She suspects resistance among the mites and, sure enough testing by an independent laboratory in August (prior to this year's treatment with acaricide) finds that 97 out of every 1000 mites are resistant to her acaricide. Take all calculation and answers to 6 decimal points Based on this information: __________ What percent of the mite population prior to the next scheduled treatment are expected to be heterozygotes? _________ If, this year, the hives are treated three times in succession. and by the end of the third treatment the acaricide has killed 100% of susceptible mites, by what percent would the mite population be reduced? R _________, r __________ What is the frequency of each allele (dominant and recessive) in the population of mites before the treatment this three-round treatment? R ________, r _______ What is the frequency of each allele after the three treatments? (note, this requires some thought (1 pt each blank) Based on the information here, would the frequency of the recessive allele been higher, lower, or the same as compared to three years ago? Would you expect any assumptions of the H-W equilibrium to have been violated over the three previous years of hive management? If so, specify which assumption (s) and provide evidence.Explanation / Answer
9.7*2=19.4 percent of the mite population are expected to be heterozygotes.
By the end of third treatment the acaricide has killed 100% so the
reduction rate=100/3=33.33%
Before treatment
Frequency of allele R=0.03, r=0.97
After three treatments there are no susceptile mites.
So R=1 r=0
Frequency of the recessive allele will remain same through successive generation.
In H-W equlibrillum we assume mutations are negligible but here mutaion has occured with quite high freqency.