Neuropeptides of the cotton fleahopper, Pseudatomoscelis seriatus (Reuter)

The cotton fleahopper, Pseudatomoscelis seriatus (Reuter), is an economically important pest of cotton, and increasing concerns over resistance, detrimental effects on beneficial insects and safety issues associated with traditional insecticide applications have led to an interest in research on novel, alternative strategies for control. One such approach requires a more basic understanding of the neurohormonal system that regulates important physiological properties of the fleahopper; e.g. the expression of specific messenger molecules such as neuropeptides. Therefore we performed a peptidomic study of neural tissues from the fleahopper which led to the first identification of the sequences of native peptide hormones. These peptide hormones include the following neuropeptides: corazonin, short neuropeptide F (sNPF), myosuppressin, CAPA-pyrokinin and CAPA-PVK peptides. The CAPA-pyrokinin, sNPF, and CAPA-PVK peptides represent novel sequences. A comparison of fleahopper neuropeptides with those of related heteropteran species indicates that they are quite different. The sNPF of P. seriatus shows, among others, a novel substitution of Leu with Phe within the C-terminal region; a modification that sets it apart from the known sNPFs of not only other Heteroptera but of other arthropod species as well. The identity of the neuropeptides native to the fleahopper can aid in the potential development of biostable, bioavailable mimetic agonists and antagonists capable of disrupting the physiological functions that these neuropeptides regulate.