Dragonflies and Damselflies: References

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Reference Link. Citation Primary biogeographic zone Disciplinary domains URL Usage
Fukunoda 2007a. Fukunoda, H., Takahashi, K. (2007) The landing from the water and the terrestial period before emergence of the final instar larvae of Epiophlebia superstes Selys (Anisoptera: Epiophlebiidae). TOMBO, Matsumoto, 49 (1/4): 15-21. East Palearctic Behaviour Development no url Check use

Key words

The exiting of the final instar larvae of Epiophlebia superstes from water to terrestrial hiding sites before emergence was investigated in the spring of 2005 and 2006, at a mountain stream (width: 2-3 m, water depth: 20-60 cm, altitude: 520-550 m) in Nurukawa, Hirakawa-shi, Aomori prefecture. The number of larvae walking on the snow (snow depth: 3-4 m) was counted during the period from 3 to 29, April. Over 14 days during 2005 and 2006, we found 193 and 188 larvae on the snow, respectively. Most of the larvae climbed and crawled westward (90.3%) on the snow cover from the mountain stream in the morning, while some larvae climbed and crawled eastward (25.8%) or changed their course to the east from the west as the sun moved from the east to the south (ca. 10:30). The larvae moved to land without snow cover 13-36 m away from the stream, and hid under fallen leaves. It took 1.5-4.5 hours to move from the stream to the hiding sites. When hiding sites were not available, the larvae continued walking on the snow for 5-6 hours traveling as far as 40-60 m from the stream. Exiting from the water was observed from 8:00 to 15:00 h with a peak between 10:00-11:00 h, and were mostly in the morning (67.7%) rather than in the afternoon (33.3%). The number of exits from the water was also influenced by weather conditions: 33+/-11 (s. d.) (n=5) on fine days, 24+/-11 (s. d.) (n=7) on fine-cloudy days and 4+/-2 (s. d.) (n=5) on cloudy days. Walking velocities of the larvae on slope (0-80o) and on vertical surfaces (90o) on the snow were 8-66cm (n=89) and 15.3+/-5.2 (s. d., n=23) cm/minute , respectively. The larvae moved faster at higher ambient temperature. The body temperature of larvae varied between 3.5 and 15.5oC, with a mean of 7+/-3.8oC (s. d.) (n=17, Fig. 5), which correlated with the ambient temperature. We could not observe any adult emergence in May or early July, the time that is supposed to be the emergence period for this species in the study area (Naraoka, 2004). Some larvae were collected in mid and late April and were brought to the lower altitudes (16 m) to observe their emergence periods. The larvae collected in mid April emerged 30.2+/-1.3 (s. d.) days (n=4) after exiting the water but those collected in late April emerged 24.0+/-1.2 (s. d.) days (n=5) after leaving the water. Also, some exiting larvae were collected in late April, and were kept in containers in the study area. They emerged 29.3+/-1.3 (s. d.) days (n=4) after departing the stream (Table 2). We concluded that the final instar larvae of Epiophlebia superstes leave the water area before their emergence during April, and their terrestrial period of life is 25-35 days.