01481nas a2200133   4500008004100000245009700041210006900138260000800207300001100215490000700226520105400233100001601287856004401303       2000                        eng d00aPossible Removal of Rival Sperm by the Elongated Genitalia of the Earwig, Euborellia plebeja0 aPossible Removal of Rival Sperm by the Elongated Genitalia of th  cJul  a667-720 v173 aSperm displacement is a sperm competition avoidance mechanism that reduces the paternity of males that have already mated with the female. Direct anatomical sperm removal or sperm flushing is known to occur in four insect orders: Odonata, Orthoptera, Coleoptera and Hymenoptera. In a fifth order, Dermaptera (earwigs), I found that the virga (the elongated rod of the male genitalia) of Euborellia plebeja seems to be used to remove rival sperm from the spermatheca (a fine-tubed female sperm storage organ). In this species, copulation lasted on average 4.6 minutes, during which time the male inserted the virga deep into the spermatheca, and then extracted it ejaculating semen from the opening of the virgal tip. The extraction of virgae (with its brim-like tip) appeared to cause removal of stored sperm in the spermatheca. The virga was as long as the body length of males, and the spermatheca was twice the female body length. The long length of the spermatheca and the possible removal function of the virga may select for virgal elongation.1 aKamimura, Y  uhttps://odonatas.myspecies.info/node/69