Movement of immature aquatic insects in a lotic habitat

Abstract

The movement of immature insects up down and across Salem Creek, Ontario, was measured with traps and nets at two week intervals from January to December 1977. Drift of most taxa was more strongly correlated with water velocity from August to December than it was over the whole year. That of Baetis, however, was not correlated with water velocity and it was significantly greater at the side of the stream than at the centre from May to July. Upstream movement, as measured in three different ways, was small compared with drift, being only 2.1, 7.3 and 15.2 percent respectively.Upstream and across stream movements were not consistently different from one another, changes in their intensity apparently merely representing changes in numbers and behaviour of the animals. It is concluded therefore that upstream movement is only random movement.Colonization of empty sediment in trays on and above the substratum confirmed that most reoccupation of denuded areas is by drift. This supports the finding that drift is far geater than random wandering of the insects.

Trophic interactions in open systems: Effects of predators and nutrients on stream food chains

“…Many stream invertebrates redistribute themselves by departing the sediments to drift short distances downstream in the water column (Bird and Hynes 1981;Bergey and Ward 1989), and benthic algae can also be transported among sites in this manner (Stevenson and Peterson 1991;Peterson 1996). Previous studies indicate that drifting accounts for most movement among habitat patches by baetids and chironomids (Bird and Hynes 1981;Bergey and Ward 1989).…”

“…Previous studies indicate that drifting accounts for most movement among habitat patches by baetids and chironomids (Bird and Hynes 1981;Bergey and Ward 1989). We therefore quantified the rate at which baetids and chironomids drifted into and out of the enclosures by placing drift nets (mesh size ϭ 0.125 mm, square mouth ϭ 0.2 ϫ 0.2 m, length ϭ 1 m) to intercept the flow at their upstream or downstream end.…”

Flow in culverts as a potential mechanism of stream fragmentation for native and nonindigenous crayfish species

“…Within these broad groups, however, there may be unique examples of a single species or family that demonstrates a greater tendency than others to move upstream within or along the stream's substrate. For example, in one study, upstream movement of riffle beetle larvae (Elmidae) compensated for 180% to 300% of the number of drifting larvae (Bird and Hynes, 1981) and, as mentioned previously, more than 2.8 times the number of drifting caddisflies (comprised of four species) moving upstream in another study (Bergey and Ward, 1989).…”

“…Freilich (1991) found that marked Pteronarcys nymphs (Plecoptera) moved between zones of attraction, both up and downstream. Bird and Hynes (1981) provide evidence that the direction of movement within the substrate is random.…”

“…It often involves short distances of 1 to 10 meters over 24 hours (Elliott, 1971). Yet, over the course of many days, these invertebrates may move as much as 40 to 300 meters (Ball andHooper, 1963 (reported in Bird andHynes, 1981); Freilich, 1991;Erman, 1986). A few stream insects will migrate up a stream, moving long distances, through several types of habitat (e.g., riffles, pools, sunny, shady, etc).…”