Characteristics of phenol oxidases in Mormoniella vitripennis (Walker)

Abstract

The activation of phenol oxidase activity in Mormoniella vitripennis (Walker) homogenates is shown to be similar to that in Drosophila and Musca. Activation has an initial lag period and then increases autocatalytically. The initial rate of activation increases with increasing temperature, but the maximum activity reached by incubated homogenates decreases with increasing temperature. Activity reaches a maximum during the third larval instar just prior to prepupation, decreases to 0 during the first 40 hr following prepupation, and increases to one-sixth of the prepupal activity during pigmentation. Specific maximum activity differs from maximum activity only in prepupae and adults.