I. Romana et al., THE OVARY IS A SOURCE OF CIRCULATING ECDYSTEROIDS IN BLATTELLA-GERMANICA (DICTYOPTERA, BLATTELLIDAE), European journal of entomology, 92(1), 1995, pp. 93-103
The developmental fluctuations in immunoreactive ecdysteroids in the h
aemolymph of adult female Blattella germanica (L.) are reported. There
is a relatively low titre in freshly ecdysed females, an increase dur
ing vitellogenesis to a peak at choriogenesis, and a decrease after ov
ulation. These fluctuations parallel those of ecdysteroid content in t
he ovary. In addition, haemolymph ecdysteroid levels are reduced follo
wing ovariectomy, and single ovarioles incubated in vitro effectively
release ecdysteroids into the medium. The data strongly suggest that t
he ovaries are a major source of circulating ecdysteroids in adult fem
ales of this species. Since the prothoracic gland degenerates shortly
after the imaginal moult, the presence of ecdysteroids in the haemolym
ph of ovariectomized females suggests that there are other tissues tha
t also serve as a source of these circulating hormones during the repr
oductive cycle of B. germanica.