Testosterone, progesterone, and FSH levels in Pimpla turionellae L. (Hymenoptera: Ichneumonidae) and its host Galleria mellonella L. (Lepidoptera: Pyralidae)

Abstract

Various vertebrate-type steroid and gonadotropin hormones have been identified in invertebrates, including insects; however, studies in this area are not sufficient to presume a generalized role for these hormones. We identified testosterone, progesterone, and follicle-stimulating hormone (FSH) in the whole-body homogenates of Galleria mellonella L. (Lepidoptera: Pyralidae) and its parasitoid Pimp la turionellae L. (Hymenoptera: Ichneumonidae). Testosterone concentration significantly decreased from early instars to last instars and pupal stages of G. mellonella; however, no significant difference was observed in progesterone levels at different stages. FSH concentration reached the highest level at the pupal stage of G. mellonella. No significant difference was observed in testosterone, progesterone, and FSH concentrations in young and mature adults of the parasitoid P turionellae for both sexes. We also monitored the changes in testosterone, progesterone, and FSH levels over 2, 6, and 24 h in parasitized G. mellonella pupae. During the experimental periods no significant difference in hormone levels was found between controls and parasitized G. mellonella pupae.