|Nabli, Henda - UNIV OF MO|
|Wright-Osment, Maureen - UNIV OF MO|
|Okuda, Takashi - UNIV OF MO|
Submitted to: In Vitro Cellular and Developmental Biology - Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 17, 2005
Publication Date: April 1, 2005
Citation: Goodman, C.L., Wagner, R.M., Nabli, H., Wright-Osment, M., Okuda, T., Coudron, T.A. 2005. Partial morphological and functional characterization of the corpus allatum-corpus cardiacum complex from the two-spotted stinkbug, perillus bioculatus (hemiptera: pentatomidae). In Vitro Cellular and Developmental Biology - Animals 41:71-76. Interpretive Summary: Stinkbugs can be used to help control pest insects because of their ability to attack and kill pests known to damage crops. Given this, it is important to understand various aspects of how stinkbugs function in order to find ways of improving their mass production. The primary goal of this work was to develop a test system that can be used to understand the role a hormone, known as JH, plays in reproduction, development and diapause (a state similar to hibernation) of these insects. For our studies, we removed the organ that produces this hormone from the two-spotted stinkbug and found that the JH it produced was similar to that of other insects and that we could encourage its production with a chemical called t-t-farnesol. Furthermore, we found that these heightened JH production levels were similar for insects of different ages and sexes and yet lower for insects raised in cooler temperatures with less light (which is important in diapause). We expect these results to impact scientists by providing them with a means of studying the JH-like substances from stinkbugs to help them understand their importance in insect reproduction and diapause, both key factors in insect mass production schemes. This information can in turn be used by beneficial insect companies to help them improve the quantity, quality and storage of the stinkbugs they are growing to be sold as control agents to growers.
Technical Abstract: An in vitro assay for studying the synthetic activities of the corpus cardiacum (CC) ' corpus allatum (CA) complex from the two-spotted stinkbug, Perillus bioculatus (Hemiptera: Pentatomidae), was developed. The CA is known to produce juvenile hormone (JH) in insects, hormones important in development and reproduction. Little is known about the JHs in hemipteran insects, the true bugs. The primary goal of the present work was to develop an in vitro CA assay to enable further detailed studies to be performed. Initial characterization of an extract of the assay incubation medium indicated that primarily one activity was synthesized that was stimulated by t-t-farnesol (a known precursor for JH III) and that this activity migrated more slowly than JH III when subjected to thin layer chromatography. These data indicate that the JH-like structure synthesized by P. bioculatus CAs has properties similar to those of other hemipteran JHs. Additionally, the effect of selected factors on CA basal synthetic activities and t-t-farnesol-stimulated activities was determined, including the effects of addition of various compounds to the medium as well as that of the age and sex of the insects. Lastly, the complexes from adults reared under conditions that produced diapause-like effects were found to be unresponsive to stimulation by t-t-farnesol, suggesting a slow regulation component similar to the hemipteran Pyrrhocorris apterus.