Aquatic flies (Diptera) in phytotelmata of Neotropical Zingiberales plants

Abstract

ABSTRACT Phytotelmata are temporary pools of rainwater impounded on plants. These pools provide aquatic habitats in which immature stages of insects live. Zingiberales plants can have two types of phytotelmata, the bract pool on the inflorescence and the tubes formed as young leaves unroll. The Diptera fauna of these habitats are poorly known. This study reports on a systematic inventory of invertebrate communities from Zingiberales in Costa Rica and Peru. Collections of invertebrates were extracted from 251 phytotelmata representing six species of Zingiberales – Heliconiaceae: Heliconia robusta Pax, Heliconia stricta Huber, and Heliconia tortuosa Griggs; Marantaceae: Calathea lutea Schult; and Zingiberaceae: Alpinia purpurata (Vieillard) K. Schumann and Renealmia spp. Aquatic Diptera (620 larvae and pupae) were found in 34 samples (32 bract pools and 2 leaf rolls). These Diptera were extracted, sorted and identified to 22 morpho species in 5 families of aquatic ‘Nematocera’, two families of aquatic Brachycera, and one group of undetermined aquatic Brachycera families. Chironomidae (159 individuals, 3 species) were the numerically dominant family, then Syrphidae (141 individuals, 3 species), and Psychodidae (81 individuals, 2 species). The Peru phytotelmata contained more species of Diptera than the Costa Rica phytotelmata. Altogether, four new host associations are documented between aquatic Diptera and Zingiberales phytotelmata habitats in Costa Rica and 14 such records in Peru. Results of a cluster analysis indicate that communities of aquatic Diptera varied between sampling sites and within and between plants. Phytotelmata add to habitat heterogeneity and are likely to increase diversity of aquatic Diptera and other taxa; therefore, phytotelmata should be included in assessments of aquatic Diptera.