Juvenile hormone III (JH III) and its immediate precursor, methyl farnesoate (MF), are synthesized and released by the corpora allata (CA) in cockroach embryos. We have determined how much of each of these is produced by the glands in several species of cockroach, including the viviparous Diploptera punctata; the oviparous Periplaneta americana, Blatta orientalis, and Eurycotis floridana; and the ovoviviparous Blaberus discoidalis, Rhyparobea maderae, Nauphoeta cinerea, and Byrsotria fumigata. Preliminary work is also under way to examine JH titers in cockroach embryos and to compare these with in vitro products of the CA. Methyl farnesoate, along with JH III, was produced by the CA of N. cinerea and R. maderae. Moreover, the rates and patterns of JH III and MF synthesized and released varied greatly among all species. Generally, a smaller fraction of JH III and MF was released from the CA while a greater fraction was retained within them. Why the CA of some cockroach embryos produce and release MF is still unclear.
Species 1: Blattaria Blaberidae Diploptera punctata (Pacific beetle cockroach)
Species 2: Blattaria Blaberidae Blaberus discoidalis (discoid cockroach)
Species 3: Blattaria Blaberidae Rhyparobia maderae (Madeira cockroach)
Keywords: methyl farnesoate, evolution
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