show Abstracthide AbstractThe research material is the red flour beetle, Tribolium castaneum. A random collection of 100 males and 100 females was made from the stock culture and their death-feigning behavior was observed. Males and females (10 of each) with the shortest duration of death-feigning were selected to propagate short-duration lines (S-lines); similarly, 10 of each with the longest duration were selected to propagate long-duration lines (L-lines). The males and females of each line were placed in a plastic cup with 20 g of medium and allowed to lay eggs for one week. The pupae from the eggs were stored in separate-sex groups in other plastic cups and allowed to emerge. When the adults reached 10-15 days old, 100 males and 100 females were randomly collected from each line and their death-feigning was observed again (F1 generation). The same procedure was carried out in each generation. After more than 30 generations, the DNA of the S-line and L-line was extracted.