Polygyny is the most common mating pattern amongst Phrynus longipes as the males are free to mate with many females. The females, due to their caring for the egg sac, are prohibited from mating freely with multiple males. In the cases where polygyny does not occur, Phrynus longipes has been observed to take part in mate-multiply behavior. This means that one male will mate multiple times with the same female in order to ensure full paternal-ship of every clutch. This type of monogamous mating better ensures that the male will have plentiful offspring of his own.
