Observations on the ecology of Simuliidae from the River Frome, Dorset

Abstract

Abstract. 1. The species of Simulium present at twenty‐seven stations in the River Frome and some of its tributaries are recorded. 2. In the lower reaches of the river Simulium omatum and Simulium lineatum have basic life histories comprising four generations of larvae annually. 3. At other stations the annual pattern is modified by weed cutting and flow regulations and by position in the river system. 4. In winter generations the larvae and pupae are larger than at other times of the year. A survey of the size of pupae at ten stations in October 1973 indicated that temperature could account for variations in size.

Realism of model ecosystems: an evaluation of physicochemistry and macroinvertebrate assemblages in artificial streams

“…The Frome and its tributaries have been studied extensively over the past 30 years, with data published describing aspects of the ecology (e.g. Ladle et al, 1977;Mann, 1982;Pardo & Armitage, 1997) and water chemistry of this lowland system (e.g. Casey, 1975;Neal et al, 1998).…”

Walphy, un projet expérimental de réhabilitation de cours d'eau : suivis hydromorphologiques et écologiques

“…Le Cb2 suit la même tendance que pour la station de contrôle et la station aval, mais avec une plus nette augmentation du sous-indice ln, Le dendrogramme (Fig. 11) (Ladle et al, 1977). (Ladle et al, 1977).…”

Life history patterns of river invertebrates

“…Consequently it is likely that there will be a strong element of interspecific competition for food and feeding sites. In fact spatial segregation of species is often well marked and the individual species are in many cases restricted to particular zones of the river system (Ladle et al, 1977). Feeding site selection is by a combination of oviposition site choice and subsequent readjustment by drifting.…”

“…Simuliidae in chalk streams are mostly multivoltine and each generation may inhabit a different zone of the river (Ladle et al, 1977). A few specialised forms which inhabit winterbournes (Metacnephia amphora Ladle & Bass) or riffles downstream of impounded sections of river (Simulium posticatum Meigen) have only a single annual generation and in these oviposition behaviour places the eggs in the dry bed or banks of the river (Ladle et al, 1985).…”

“…Interspecific zonation -many families of insects, for example, show strongly developed patterns of species zonation (Ladle et al, 1977). Intraspecific zonation -life histories and growth patterns show systematic variation, within populations, along the length of streams (Fig.…”