Please refer also to the following links for details on this group:
Sialidae = Link 1
The alderflies are a small family and the larvae of Sialis and several other genera are entirely aquatic feeding partly on other aquatic insects and smaller animals in their environment. Adults are dark, ca. 25 mm. max. long. The eggs are laid in masses on vegetation over or near water. The larvae differ from the Corydalidae by having a terminal filament, seven pairs of lateral filaments and no hooked anal prolegs.
Sialids have not been used in biological pest control, but are certainly important in the natural control of insects in aquatic habitats.