Appendix 1: Number of individuals per macroinvertebrate taxa-stage (including separately adult, larvae and nymphs) captured by each sampling technique, the dip-net and fyke nets, in two sampling days per month (the dip-net was only used in March). Taxa which included adult, larvae or nymphs with small body size (<5 mm) are indicated with +.

Dip-net / Fyke net
Macroinvertebrate taxa-stages / March adults / March larvae / March adults / March larvae / April adults / April larvae
Bassomatophora
Physa spp. + / 179 / 23 / 28
Planorbis spp. + / 1
Coleoptera
Bagous spp. + / 1 / 5
Dryops spp. + / 1 / 1
Agabus conspersus (Marsham 1802) / 1 / 1
Agabus nebulosus (Forster, 1771) / 1 / 7 / 3
Agabus spp. larvae + / 23 / 1 / 1
Colymbetes fuscus (Linnaeus, 1758) / 8 / 39
Cybister lateralimarginalis (De Geer, 1774) / 3 / 3 / 8 / 6
Dytiscus circumflexus Fabricius, 1801 / 2 / 2 / 2
Hydroporus gyllenhali Schiödte, 1841+ / 1
Hydroporus lucasi Reiche, 1866 / 5
Hydroporus spp. and Hygrotus spp.+ / 2
Ilybius montanus (Stephens, 1828) and Agabus bipustulatus (Linnaeus, 1767) / 6
Laccophilus minutus (Linnaeus, 1758) + / 15 / 1
Rhantus hispanicus Sharp, 1882 / 1 / 3 / 13
Rhantus suturalis (McLeay, 1825) / 1 / 4 / 31
Rhantus spp. + / 10 / 1
Helophorus spp. + / 1 / 1 / 9
Anacaena lutescens (Stephens, 1829) + / 1
Berosus affinis Brullé, 1835 / 1
Berosus guttalis Rey, 1883 / 19 / 1
Berosus signaticollis (Charpentier, 1825) / 1 / 3
Berosus spp. larvae + / 4 / 10
Enochrus bicolor (Fabricius, 1792) / 3
Enochrus fuscipennis (C.G. Thomsom, 1884) / 6
Hydrobius fuscipes (Linnaeus, 1758) and Limnoxenus niger (Zschach, 1788) + / 5 / 12 / 6 / 4 / 18
Hydrochara flavipes (Steven, 1808) / 12 / 13
Hygrobia hermanni (Fabricius, 1775) / 2
Decapoda
Procambarus clarkii (Girard, 1852) / 3 / 4 / 2
Ephemeroptera
Cloeon dipterum (Linnaeus, 1761) + / 358 / 15
Heteroptera
Corixa affinis Leach, 1817 / 6 / 6 / 5
Corixidae + / 2 / 7
Sigara lateralis (Leach, 1817) + / 1
Gerris thoracicus Schummel, 1832 / 15 / 22 / 10 / 12 / 10 / 7
Microvelia pygmaea (Dufour, 1833) + / 1
Anisops sardeus Herrich-Schäffer, 1849 / 25 / 5 / 2
Notonecta glauca Linnaeus, 1758 / 19
Notonecta maculata Fabricius, 1794 / 9
Notonecta spp. / 68 / 42 / 66
Plea minutissima Leach, 1817 + / 1
Saldidae / 2 / 1
Odonata
Aeshna affinis Vander Linden, 1823 / 4
Crocothemis erythraea (Brullé, 1832) / 1
Sympetrum fonscolombei (Selys, 1841) / 103 / 35 / 6
Sympetrum sanguineum (Müller, 1764) / 4
Sympetrum striolatum (Charpentier, 1840) / 2 / 3
Dip-net / Fyke net
Diptera / March larvae / March nymph / March larvae / March nymph / April larvae / April nymph
Culicidae + / 1 / 1 / 1
Rhagionidae + / 4