Ecological Research

, Volume 29, Issue 6, pp 1025–1032 | Cite as

Does egg dispersal occur via the ocean in the stick insect Megacrania tsudai (Phasmida: Phasmatidae)?

  • Shun KobayashiEmail author
  • Ryota Usui
  • Kouta Nomoto
  • Mineyuki Ushirokita
  • Tetsuo Denda
  • Masako Izawa
Original Article


Although insects expand their distribution by various ways, generally only the adult phase has been taken into consideration in research on dispersal. In Megacrania tsudai, it has been proposed that eggs are dispersed through seawater. To test this hypothesis, eggs were treated under normal condition (NC) on wet cotton swabs, and marine condition (MC), floating on salt water for 30, 60, 90, and 365 days. In addition, eggs in the NC and MC treatment groups were dissected every 10 days to verify the developmental stage. The hatching rates in the NC and MC treatment groups were not significantly different among the five treatment groups. However, the egg period, time from laying to hatching, in the MC treatment group was significantly longer than that in any other treatment groups. The egg period was lengthened when the floating period on seawater was longer. The time of the start of egg development was similar in the NC and MC treatment groups, but the developmental speed was slower in the MC treatment group. These results support that M. tsudai can expand its distribution by dispersing its eggs through seawater, probably thanks to specific characteristics of eggs that allow their survival when they float in the sea.


Egg period Hatching rate Megacrania tsudai Salinity tolerance Seawater dispersal 



We appreciate Takeshi Sasaki of The University Museum (Fujukan), University of the Ryukyus for his valuable advices and support of this research. We also thank Yuki Yamakoshi, Keita Nakamura, and Hiromu Tanimoto for their help and two reviewers for their valuable comments. This study was partly supported by the ‘International Research Hub Project for Climate Change and Coral Reef/Island Dynamics’ from the University of the Ryukyus and The KAIGIN Environment Fund—managed by THE OKINAWA KAIHO BANK, LTD.


  1. Andersen NM, Cheng L (2004) The marine insect Halobates (Heteroptera: Gerridae): biology, adaptations, distribution, and phylogeny. In: Gibson RN, Atkinson RJA, Gordon JDM (eds) Oceanography and marine biology: an annual review 42. CRC Press, Florida, pp 119–180CrossRefGoogle Scholar
  2. Azuma S, Yafuso M, Kinjo M, Hayashi M, Kohama T, Sasaki T, Kimura M, Kawamura F (2002) Check list of the insect of the Ryukyu Islands, 2nd edn. The Biological Society of Okinawa, OkinawaGoogle Scholar
  3. Basden EB (1955) Egg-laying of the stick-insect (Carausius morosus Brlinner) (Orthop., Phasmidae). Entomol Mon Mag 61:201–202Google Scholar
  4. Beament JWL (1961) The water relations of insect cuticle. Biol Rev 36:281–320PubMedCrossRefGoogle Scholar
  5. Bedford GO (1976) Description and development of the eggs of two stick insects (Phasmatodea: Phasmatidae) from New Britain. Aust J Entomol 15:389–393CrossRefGoogle Scholar
  6. Bedford GO (1978) Biology and ecology of Phasmatodea. Annu Rev Entomol 25:129–149Google Scholar
  7. Cheng L (1985) Biology of Halobates (Heteroptera: Gerridae). Annu Rev Entomol 30:111–134CrossRefGoogle Scholar
  8. Clark JT (1979) A key to the eggs of stick and leaf insects (Phasmida). Syst Entomol 4:325–331CrossRefGoogle Scholar
  9. Cochran WG (1954) Some methods for strengthening the common χ2 tests. Biometrics 10:417–451CrossRefGoogle Scholar
  10. Dehgan B, Yuen CKKH (1983) Seed morphology in relation to dispersal, evolution, and propagation of Cycas L. Bot Gaz 144:412–418CrossRefGoogle Scholar
  11. Foster WA, Treherne JE (2008) The ecology and behaviour of a marine insect, Halobates fijiensis (Hemiptera: Gerridae). Zool J Linn Soc 86:391–412CrossRefGoogle Scholar
  12. García-González F, Gomendio M (2003) Oviposition site selection and oviposition stimulation by conspecifics in the golden egg bug (Phyllomorpha laciniata): implications for female fitness. Behav Ecol Sociobiol 53:385–392Google Scholar
  13. Gibbs GW (1996) A large migration of the Australian painted lady butterfly, Vanessa kershawi (McCoy), to New Zealand. N Z Entomol 4:14–21CrossRefGoogle Scholar
  14. Hinton HE (1969) Respiratory systems of insect egg shells. Annu Rev Entomol 25:343–368CrossRefGoogle Scholar
  15. Hirsh H, Marle T (2002) Damage and recovery of Cycas micronesica after Typhoon Paka. Biotropica 34:598–602CrossRefGoogle Scholar
  16. Hsiung C-C (2007) Revision of the genus Megacrania Kaup (Cheleutoptera: Phasmatidae). J Orthop Res 16:207–221CrossRefGoogle Scholar
  17. Iwata S, Watanabe M (2004) Saline tolerance of young Zygopteran larvae inhabiting the emergent plants community established in estuaries. Jpn J Entomol (New Ser) 7:133–141 (in Japanese with English summary)Google Scholar
  18. Kiflawi M, Blaustein L, Mangel M (2003) Oviposition habitat selection by the mosquito Culiseta longiareolata in response to risk of predation and conspecific larval density. Ecol Entomol 28:168–173CrossRefGoogle Scholar
  19. Krebs CJ (2001) Ecology: the experimental analysis of distribution and abundance, 5th edn. Benjamin Cummings, San FranciscoGoogle Scholar
  20. Leader JP (1972) Osmoregulation in the larva of the marine caddis fly, Philanisus plebeius (Walk.) (Trichoptera). J Exp Biol 57:821–838Google Scholar
  21. McLachlan A, Brown AC (2006) The ecology of sandy shores, 2nd edn. Academic Press, AmsterdamGoogle Scholar
  22. Minakawa N, Kurowski K, Yabe M (2001) Salinity tolerance of the diving beetle Hygrotus impressopunctatus (Coleoptera: Dytiscidae) and its implication for insect dispersal. Entomol Sci 4:393–397Google Scholar
  23. Nakanishi H (1988) Dispersal ecology of the maritime plants in the Ryukyu Islands, Japan. Ecol Res 3:163–173CrossRefGoogle Scholar
  24. Patrick ML, Bradley TJ (2000) The physiology of salinity tolerance in larvae of two species of Culex mosquitoes: the role of compatible solutes. J Exp Biol 203:821–830PubMedGoogle Scholar
  25. Rikiishi K (1974) Note on the Kuroshio meander. J Oceanogr 30:42–45Google Scholar
  26. Roberts D (1996) Mosquitoes (Diptera: Culicidae) breeding in brackish water: female ovipositional preferences or larval survival? J Med Entomol 33:525–530PubMedGoogle Scholar
  27. Stone BC (1967) Studies of Malaysian Pandanaceae I, polymorphism in Pandanus odoratissimus L.f. of Asia. Gard Bull Singap 22:231–257Google Scholar
  28. Udvardy MDF (1969) Dynamic zoogeography: with special reference to land animals. Van Nostrand Reinhold, New YorkGoogle Scholar
  29. Ueno S (1978) The Thalassoduvalius (Coleoptera, Trechinae) of the Izu Area, Central Japan. Mem Natl Sci Mus 11:123–130Google Scholar
  30. Ushirokita M (1998) Eggs of stick insect drifting in the wake of screw pine’s seed. Insectarium 35:108–115 (in Japanese)Google Scholar
  31. Wang C-H, Chu Y-I (1982) The morphological study of the egg shell of the Tsuda’s giant stick insect Megacrania alpheus Westwood. NTU Phytopathol Entomol 9:98–109Google Scholar
  32. Williams DD, Williams NE (1998) Aquatic insects in an estuarine environment: densities, distribution and salinity tolerance. Freshw Biol 39:411–421CrossRefGoogle Scholar
  33. Yamasaki T (1991) Occurrence of Megacrania alpheus (Cheleutoptera: Phasmatidae) in Iriomote-jima Island, Ryukyus. Proc Jpn Soc Syst Zool 44:49–56Google Scholar

Copyright information

© The Ecological Society of Japan 2014

Authors and Affiliations

  • Shun Kobayashi
    • 1
    • 2
    Email author
  • Ryota Usui
    • 3
  • Kouta Nomoto
    • 4
  • Mineyuki Ushirokita
    • 5
  • Tetsuo Denda
    • 6
  • Masako Izawa
    • 6
  1. 1.Graduate School of Engineering and ScienceUniversity of the RyukyusNishiharaJapan
  2. 2.Japan Society for the Promotion of ScienceTokyoJapan
  3. 3.Graduate School of AgricultureUniversity of the RyukyusNishiharaJapan
  4. 4.Itami City Museum of InsectsItamiJapan
  5. 5.ECO-PLANNING RESEARCH co.Ltd.TokyoJapan
  6. 6.Faculty of ScienceUniversity of the RyukyusNishiharaJapan

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