• Sperm flushing;
  • sperm competition;
  • semen ingestion;
  • genitalia;
  • Orthoptera;
  • Truljalia hibinonis.

ABSTRACT. A novel combination of adaptations resulting from sperm competition is demonstrated for the tree cricket Truljalia hibinonis (Matsumura) (Podoscirtinae: Gryllidae: Orthoptera). 87.5% of the semen of previous males is displaced onto the penis of the copulating male and is removed at the end of copulation. Semen thus removed is ingested during post-copulatory oro-genital grooming. No overt morphological adaptations for sperm removal were observed and, on the basis of anatomical evidence, it is suggested that rivals' semen is flushed out of the female?s sperm storage organ by the semen of the last male.