Development of experimental mesocosms for cicada nymphs Graptopsaltria nigrofuscata: methodology and research recommendations

Abstract

The experimental mesocosm, an artificial enclosure system for soil organisms, is a major research tool in soil ecology. Development of a rearing method for target organisms within mesocosms is essential for conducting mesocosm experiments. Cicadas (Hemiptera: Cicadoidea) are assumed to play important roles as root feeders and ecosystem engineers in soil ecosystems. Nonetheless, their ecological roles have not been investigated to the same extent as other root -feeding species, possibly because it is difficult to rear cicadas in mesocosm experiments. Here, we report a rearing method for cicada nymphs (Graptopsaltria nigrofuscata) in an experimental mesocosm over a period of 3 months. We prepared eight polyvinyl chloride cages filled with mineral soil in a forest. One final instar (0.33 0.10 g fresh weight [MeanSD]), and one early instar cicada nymph (2.230.16 g fresh weight [MeanSD]) were placed into each mesocosm cage with a seedling of Japanese larch (Larix kaempferi) as a food source. After 3 months, 75 % (6 to 8) of final instar cicada nymphs survived and increased in fresh weight by approximately 6 % since the beginning of the experiment, whereas all early instar nymphs had died. This is the first study to provide a detailed rearing method for cicada nymphs in East Asia, a region that harbors a high species diversity of cicadas. Our mesocosm system could be an effective tool for understanding the ecology and ecological roles of final instar cicada nymphs in belowground ecosystems.

Keywords

• above- and belowground linkage
• field experiment
• rearing method
• root feeders