摘要Baculoviruses constitute a large group of invertebrate DNA viruses,predom-inantly infecting larvae of the insect order Lepidoptera.During a baculovirus infection,the virus spreads throughout the insect body producing a systemic infection in multi-ple larval tissues,included the central nervous system (CNS).As a main component of the CNS,neuropeptides are small protein-like molecules functioning as neurohormones,neurotransmitters,or neuromodulators.These peptides are involved in regulating animal physiology and behavior and could be altered after baculovirus infection.In this study,we have investigated the effect of Spodoptera exigua multiple nucleopolyhedrovirus (SeM-NPV) infection on expression ofSpodoptera exigua neuropeptides and neuropeptide-like genes.Expression of the gene encoding a polypeptide that resembles the well-known in-sect neuropeptide proctolin and named as proctolin-like peptide (PLP),was downregulated in the larval brain following infection and was chosen for further analysis.A recombinant Autographa califomica multiple nucleopolyhedrovirus (AcMNPV) overexpressing the C-terminal part of the PLP was generated and used in bioassays using S.exigua larvae to study its influence on the viral infection and insect behavior.AcMNPV-PLP-infected lar-vae showed less locomotion activity and a reduction in growth compared to larvae infected with wild type AcMNPV or mock-infected larvae.These results are indicative of this new peptide as a neuromodulator that regulates visceral and skeletal muscle contractions and offers a novel effector involved in the behavioral changes during baculovirus infection.