Non-fertile sperm delay female remating

摘要: Sperm competition is thought to be responsible for the tremendous inter- and intraspecific variation in sperm number1 size2. But why several animals produce a range of types3,4, some which are incapable fertilizing female's eggs4, has remained unexplained nearly 100 years5. We have found that non-fertile protect male's reproductive investment by delaying female remating polyandrous green-veined white butterfly, Pieris napi (Pieridae).