Enhancement of the biological activity of nucleopolyhedrovirus through disruption of the peritrophic matrix of insect larvae by chlorfluazuron

• Published in: Pest management science Vol. 63; no. 1; pp. 68 - 74
• Main Authors: Guo, H.F, Fang, J.C, Liu, B.S, Wang, J.P, Zhong, W.F, Wan, F.H
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.01.2007; Wiley; Wiley Subscription Services, Inc
• Subjects: Animals; application rate; Autographa californica multiple nucleopolyhedrovirus; Biological and medical sciences; Biological control; biosynthesis; Body Weight; chitin; Chitin - antagonists & inhibitors; chlorfluazuron; Control; environmental scanning electron microscopy; Fundamental and applied biological sciences. Psychology; inhibitors; Insect control; insect growth; insect pests; Insects; Larva; larvae; mechanism of action; Nucleopolyhedrovirus; peritrophic matrix; peritrophic membrane; Pest control; Pest Control, Biological - methods; pesticide synergists; Phenylurea Compounds; Phytopathology. Animal pests. Plant and forest protection; plant pests; Protozoa. Invertebrates; Pyridines; Spodoptera - virology; Spodoptera exigua; Spodoptera litura; Nucleopolyhedrovirus; Entomopathogen; Insecticide; Insecta; Spodoptera exigua; Chitin synthesis inhibitor; Pest; Baculoviridae; Environmental microscopy; Ureas; Scanning electron microscopy; peritrophic matrix; chlorfluazuron; Pesticides; Peritrophic membrane; Biological activity; Virus; Spodoptera litura; Larva; Arthropoda; Lepidoptera; Noctuidae; Disruption; Invertebrata; environmental scanning electron microscopy
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.1316

The enhancement of Spodoptera litura (F.) nucleopolyhedrovirus (SlNPV) activity using the chitin synthesis inhibitor chlorfluazuron was investigated. When tested against fifth-instar S. litura larvae, chlorfluazuron produced synergistic effects at doses of 0.05 and 0.025 microgram per insect, and additive effects at doses of 0.1 and 0.2 microgram. Furthermore, the time required for SlNPV to kill larvae was significantly reduced by chlorfluazuron at all doses tested. The activity and killing speed of Autographa californica (Spey) nucleopolyhedrovirus (AcMNPV) against third-instar Spodoptera exigua (Hübner) larvae were similarly improved by chlorfluazuron at a dose of 0.05 microgram per larva. Furthermore, the growth of S. exigua was significantly retarded by chlorfluazuron. Environmental scanning electron microscopy (ESEM) showed that the peritrophic matrices (PMs) of S. litura exposed to chlorfluazuron alone, or the combination treatment, were markedly disrupted. Obvious ruptures on the outer surfaces of the PM were observed, which potentially facilitated the passage of virions through the matrix.