Observations on rearing of Brechmorhoga Kirby, 1894 (Insecta: Odonata) nymphs under artificial conditions

Abstract

The goal of this work was to contribute to the improvement of a rearing method for Brechmorhoga that would allow a greater success in adult emergence. We sampled a total of 300 Brechmorhoga nymphs in association with a macrophyte in the Been stream, southern Amazonas state, Brazil. Out of the 300 sampled nymphs, only 60 were appropriate for rearing outside their natural habitat, as they were in the penultimate and last developmental stages. The tested methods for nymph rearing were: no substrate, artificial substrate (filter paper strips) and natural substrate (macrophyte). All methods were tested in laboratory and greenhouse. All adults obtained were recorded in the greenhouse vivaria with macrophyte. The results of the log-rank test showed a significant difference between treatment with natural substrate in laboratory and in greenhouse; and between treatments without substrate and with natural substrate in laboratory. We concluded that the rearing of Brechmorhoga under artificial conditions was more efficient in the presence of macrophytes in greenhouse vivaria.