Co-Authors:
Feldlaufer, M.F., Insect and Nematode Hormone Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, United States
Svoboda, J.A., Insect and Nematode Hormone Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, United States
Thompson, M.J., Insect and Nematode Hormone Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, United States
Wilzer, K.R., Insect and Nematode Hormone Laboratory, Agricultural Research Service, U.S. Department of Agriculture, Beltsville, MD 20705, United States
Abstract:
Four age groups (0-1 h; 1-18 h; 24-40 h; 72-88 h) of unfertilized eggs of the tobacco hornworm, Manduca sexta, were examined for the presence of free ecdysteroids and ecdysteroid conjugates. High levels (42.46-51.17 μg/g fresh wt) of 26-hydroxyecdysone 26-phosphate were found in all age groups with lower levels (5.30-9.38 μg/g fresh wt) of 26-hydroxyecdysone 2-phosphate. The 22-glucoside of 26-hydroxyecdysone was not detected in any age group, and only trace amounts (<100 ng/g fresh wt) of free 26-hydroxyecdysone were present. These results contrast sharply with the dynamic changes observed in the ecdysteroid titer in fertilized eggs and indicate that those changes are the direct result of either fertilization and/or embryogenesis. © 1988.