Titers of ecdysone, 20-hydroxyecdysone and juvenile hormone III throughout the life cycle of a hemimetabolous insect, the ovoviviparous cockroachNauphoeta cinerea

Quantity does matter. Juvenile hormone and the onset of vitellogenesis in the German cockroach

“…In hemimetabolous species, the more prolonged secretion of ecdysteroids, or the occurrence of a double peak of ecdysteroids, prior to the imaginal molt has been related to the commitment to metamorphosis (Nijhout, 1994). The concentrations of ecdysteroids in the penultimate and last larval instars of B. germanica were similar to those measured in G. bimaculatus (Gerstenlauer and Hoffmann, 1995) and S. gregaria (Tawfik et al, 1996), but one order of magnitude lower than those measured in N. cinerea (Lanzrein et al, 1985). The contrast between the high amounts of circulating ecdysteroids in larvae (produced by the prothoracic glands) and the low amounts present in the adult female (produced by the ovaries) (Pascual et al, 1992;Romañá et al, 1995) 1A) is readily apparent.…”

“…The peak concentration was higher in the penultimate than in the last larval instar, but the secretion of ecdysteroids was more prolonged in the latter. This pattern is typical of a number of hemimetabolous species, like the cockroach Nauphoeta cinerea (Lanzrein et al, 1985), the cricket Gryllus bimaculatus (Gerstenlauer and Hoffmann, 1995) and the locust Schistocerca gregaria (Tawfik et al, 1996). In hemimetabolous species, the more prolonged secretion of ecdysteroids, or the occurrence of a double peak of ecdysteroids, prior to the imaginal molt has been related to the commitment to metamorphosis (Nijhout, 1994).…”

LC/MS/MS identification of 20-hydroxyecdysone in a scorpion (Liocheles australasiae) and its binding affinity to in vitro-translated molting hormone receptors

“…The maximum concentration of 20E for the large titer peak was estimated to be 1.5 mg/mL in the hemolymph of the last (fifth) instar larva of the tobacco hornworm Manduca sexta (Bollenbacher et al, 1981). A similar ecdysteroid titer profile was also recorded in the ovoviviparous cockroach Nauphoeta cinerea (Lanzrein et al, 1985), in which the maximum concentrations of 20E and E were estimated to be approximately 3.5 and 0.15 mg/mL, respectively. Since the immunoassay specificity for each ecdysteroid is not high, the values obtained in these studies could have been overestimated.…”

Changes in the size of corpora allata, in the juvenile hormone III titer in the hemolymph, and in the protein content of terminal oocytes throughout the first gonadotropic cycle in Aiolopus thalassinus (Insecta: Orthoptera: Acrididae)

“…An increase in CA size in relation to growth of oocytes and an increase in the JH titer in the hemolymph were reported in L. migratoria by Ferenz and Kaufner [ll] and in Nauphoeta cinerea by Lanzrein et al [29]. The presence of an immunogenic allatotropic factor in the mNSC of the brain of L. migratoria has been demonstrated by Ulrich et al [30].…”