• Korean journal of applied entomology
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• v.31 no.4
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• pp.371-378
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• 1992

The ecdysteroid titers of representive developmental stages of the blackblow fly, Phormia regina, were determined by radioimmunoassay and the effect of ecdysteroid on the oocyte maturation was investigated. Prior to every molts ecdysteroid levels began to increase sharply, suggesting ecdysteroid was the major component for egg-larval, larval-larval, and larval-pupal transformation. A difference in the levels of ecdysteroid between male and female was ob¬served during adult life span. Following the protein meal, ecdysteroid in the females increased rapidly to a maximum at 96 hr of age when terminal oocyte fully matured. Effect of ecdysteroid on oocyte development was determined for control and ecdysone-treated female flies after the liver-feeding. The growth of oocyte in the flies treated by $\mu$g of ecdysone, along with the control flies, was not facilitated. When the flies treated by 5 $\mu$g of ecdysone, however, duration of oocyte maturation was shorter than those of other two groups. This can be suggested that oocyte development in P. regina is due to the critical level of ecdysone.

• The Korean Journal of Pesticide Science
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• v.5 no.4
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• pp.11-19
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• 2001

This review discusses the effects and roles of insect hormones and insect growth regulators (IGRs) on vitellogenesis in adult insects. Insect vitellogenesis is regulated by hormones such as juvenile hormone (JH), ecdysteroids, and neurosecretory hormones (ovaryecdysteroidogenic hormone : OEH) released by neurosecretory cells, diet, and other elements(male specific protein of sperm fluid). In the fat bodies, the vitellogenins are synthesized by the stimulation of JH released by corpus allatum (CA) and ecdysteroids produced by follicle cells with the ovary in most insects. Furthermore, vitellogenins are released into the hemolymph, transported to the ovarioles by carrier protein, and incorporated into oocytes for the developing ovary. Of IGRs, juvenile hormone and its mimics such as methoprene and pyriproxifen appear to have pharmacological effects such as membrane lysis, destruction of salivary grand and midgut epithlial cells, fat body cells, and ovarian tissue, and also anti-juvenile hormone such as precocenes I and II appear to have specific cytotoxicity such as inhibition of corpus allatum and oocytes development. These results suggest that IGRs may be useful as agents for integrated pest management.