Desiccation tolerance in fully developed embryos of two cicadas, Cryptotympana facialis and Graptopsaltria nigrofuscata
Article first published online: 23 MAR 2010
© 2010 The Entomological Society of Japan
Volume 13, Issue 1, pages 68–74, March 2010
How to Cite
MORIYAMA, M. and NUMATA, H. (2010), Desiccation tolerance in fully developed embryos of two cicadas, Cryptotympana facialis and Graptopsaltria nigrofuscata. Entomological Science, 13: 68–74. doi: 10.1111/j.1479-8298.2010.00365.x
- Issue published online: 23 MAR 2010
- Article first published online: 23 MAR 2010
- Received 23 April 2009; accepted 27 July 2009.
- egg hatching;
- physiological traits;
In two Japanese cicadas, Cryptotympana facialis and Graptopsaltria nigrofuscata, with different habitat distributions, fully developed embryos hatch in response to high humidity due to rainfall. Despite the advantage of hatching on rainy days, this trait burdens embryos with an extra period of desiccation until the unpredictable advent of rain. We compared the ability of the fully developed embryos of these cicadas to endure periods of low humidity. Eggs were exposed to a combination of different humidities (43% and 75% relative humidity, RH) and durations (0–15 days), and then transferred to an environment with 100% RH to stimulate hatching. In both species, total hatching rates decreased as duration increased, although there was no significant effect of humidity. In C. facialis, a considerable proportion of the eggs hatched during the desiccation period, and the hatching rate was higher at 75% RH than at 43% RH. After transfer to 100% RH, most hatching occurred within a day regardless of the desiccation level. In G. nigrofuscata, no nymphs hatched during the desiccation periods. However, more eggs required more than a day after transfer to 100% RH to hatch after desiccation at 43% RH than at 75% RH. Consequently, the overall proportion of timely hatching of eggs (eggs hatching within a day of moisture supply) was higher after desiccation at 43% RH in C. facialis, but it was higher after desiccation at 75% RH in G. nigrofuscata. These different physiological responses of the two species may reflect adaptation to habitat dryness.