Egg Release and Egg Load in the Japanese Skimmer Orthetrum Japonicum (Odonata, Libellulidae) with Special Reference to Artificial Oviposition Egg Release and Egg Load in the Japanese Skimmer Orthetrum Japonicum (Odonata, Libellulidae) with Special Reference to Artificial Oviposition

Egg release rates were examined for the Japanese skimmer Orthetrum japonicum by dipping the abdomen of females in vials of water. The duration of egg release was about 100 sec. The number of eggs released was about 200 to 300 in both paddy fields (oviposition sites) and forests (roosting and feeding sites). Some eggs were unfertilized. The number of eggs released correlated with the number of mature eggs loaded in the abdomens. The release rate also increased linearly with the number of mature eggs loaded. Egg release was thus primarily determined by the number of mature eggs in ovaries.

Egg release rates were examined for the Japanese skimmer Orthetrum japonicum by dipping the abdomen of females in vials of water. The duration of egg release was about 100 sec. The number of eggs released was about 200 to 300 in both paddy fields (oviposition sites) and forests (roosting and feeding sites). Some eggs were unfertilized. The number of eggs released correlated with the number of mature eggs loaded in the abdomens. The release rate also increased linearly with the number of mature eggs loaded. Egg release was thus primarily determined by the number of mature eggs in ovaries.