The egg of Corduliidae

A final renewal day is September 22, 2003.

Corduliidae with the record in Kinki area are seven kinds. I haven't collected Macromia yet.　I observed Epophthalmia elegans, Somatochlora viridiaenea and Somatochlora clavata in 2001 by using the egg that a friend collected it.

How to obtaining eggs : The female of Epitheca marginata ejects a large mass of eggs. Then, a female puts that egg on the water plant. Those eggs become the string-shaped which is whitish soon. That is collected. As for Somatochlora, an egg is discharged when valvula valvae of the collected female is soaked in water.　 It doesn't lay eggs easily with Epophthalmia elegans, Macromia amphigena amphigena and Macromia daimoji in this method.　Therefore, the female which lays eggs is collected, and the egg left in valvula valvae is collected.

1. Macromia amphigena amphigena Selys　

I haven't collected an egg yet.

2. Macromia daimoji Okumura

I haven't collected an egg yet.

3. Epophthalmia elegans (Brauer)

Size: Right after laying; head diameter; 0.51mm, a short diameter 0.26mm. Just before hatching; head diameter 0.58mm, a short diameter; 0.30mm. Duration of egg : The shortest duration; 8days. Average duration; 13days. 　It is a little egg in Corduliidae.　Flight period is comparatively long, and durations of egg changes in temperature (water temperature) very much, too. The shortest durations was five days at August. Gelatine material is removed in the photograph though there is much gelatine material which surrounds an egg.

Figure10-1: Left; After laying, the 4th day Right; After laying, the 8th day (This egg is just before hatching.)

4.　Somatochlora viridiaenea Selys

Size: Right after laying; head diameter; 0.64mm, a short diameter 0.46mm. Just before hatching; head diameter 0.68mm, a short diameter; 0.50mm. Duration of egg :　The shortest duration; 18days. Average duration; 36days. 　

Figure10-2: Left; After laying, the 4th day Right; After laying, the 8th day (This egg is just before hatching.)

　

5. Somatochlora clavata Oguma

Size: Right after laying; head diameter; 0.64mm, a short diameter 0.43mm. Just before hatching; head diameter 0.66mm, a short diameter; 0.47mm. Duration of egg : The shortest duration; 50days. Average duration; 223days. 　

Figure10-3: Left; After laying, the 3rd day Right; After laying, the 50th day (This egg is just before hatching.)

　

6. Somatochlora uchidai Foerster

Size: Right after laying; head diameter; 0.65mm, a short diameter 0.42mm. Just before hatching; head diameter 0.69mm, a short diameter; 0.48mm. Duration of egg : The shortest duration; 19days. Average duration; 22days. 　

Figure10-4: Left; After laying, the 1st day Right; After laying, the 17th day (This egg is just before hatching.)

　

7. Epitheca marginata (Selys)

Size: Right after laying; head diameter; 0.73mm, a short diameter 0.36mm. Just before hatching; head diameter 0.87mm, a short diameter; 0.44mm. Duration of egg : The shortest duration; 11days. Average duration; 15days. 　

Figure10-5: Left; After laying, the 2nd day Right; After laying, the 10th day (This egg is just before hatching.)

　