Analysis of ecdysterone in Bradinopyga geminata (Rambur) larvae by reverse phase-high performance liquid chromatography, RP-HPLC (Anisoptera: Libellulidae)

Ecdysterone or 20-hydroxyecdysone (20E) is a polyhydroxylated ecdysone that plays a major role in insect growth and metamorphosis. The 20E level was analyzed in 2 larval instars of the dragonfly using RP-HPLC. The presence of 20E was demonstrated for the first time in dragonflies, with the higher levels occurring in the older larval instar (larger larvae), while in the younger instar (smaller larvae) low or negligible levels were recorded. This has implications for extending the use of odon. larvae as biocontrol agents in aquatic ecosystems.