Diel activity patterns in nymphs of an Australian mayfly Atalophlebioides sp. (Ephemeroptera : Leptophlebiidae)

摘要: Activity of nymphs Atalophlebioides sp. on the surface a stone in laboratory stream was greatest at night, with peak activity occurring about 2400 h. Most remained lower during day, but there gradual movement to upper night. Although showed anocturnal maximum both drift rates (field observation) and activity. peaks did not correspond rates. Nymphs high density (15 per stone) significantly greater level light hours (1200-1800 h) first two darkness compared densities (five no significant difference between for period 1200- Feeding behaviour observed all three densities, activities form rapid darting (duration < 1 s) 'swimming' response occurred higher density. It is postulated that relationship exists swimming (as result competition space) insect's propensity drift.