Activity of Selected Formulated Biorational and Synthetic Insecticides Against Larvae of Helicoverpa armigera (Lepidoptera: Noctuidae)

• Published in: Journal of economic entomology Vol. 110; no. 1; pp. 118 - 126
• Main Authors: Vivan, L. M, Torres, J. B, Fernandes, P.L.S
• Format: Journal Article
• Language: English
• Published: England Entomological Society of America 01-02-2017; Oxford University Press
• Subjects: Animals; Bacillus thuringiensis - physiology; biological control; Carbamate pesticides; Carbamates (tradename); chemical control; Chlorfenapyr; Chlorpyrifos; Diet; ECOTOXICOLOGY; Growth regulators; Helicoverpa armigera; Infestation; Insect Control; insecticide screening; Insecticides; Insecticides - pharmacology; Instars; Introduced species; Invasive species; Juvenile Hormones - pharmacology; Larva - drug effects; Larva - growth & development; Larva - microbiology; Larva - virology; Larvae; Mortality; Moths - drug effects; Moths - growth & development; Moths - microbiology; Moths - virology; Nucleopolyhedrovirus - physiology; Old World bollworm; Organophosphates; Pest control; Pest Control, Biological; Pesticides; Spinosad; Thiodicarb; Triflumuron; Old World bollworm; biological control; chemical control; insecticide screening; invasive species
• ISSN: 0022-0493; 1938-291X
• DOI: 10.1093/jee/tow244

This work studied 17 insecticides belonging to nucleopolyhedrovirus (NPV), Bacillus thuringiensis (Bt kurstaki and Bt aizawai), benzoylureas (insect growth regulators [IGRs]), carbamates, organophosphates, spinosyns, and diamides against larvae of Helicoverpa armigera (Hübner), invasive species in the South American continent. Larvae of different instars were fed for 7 d with untreated or insecticide-treated diets. Mortality was recorded daily for 7 d, and surviving larvae were individually weighed on the seventh day. The NPV and Bt insecticides caused 100% mortality of first-instar larvae and first-instar and second-instar larvae, respectively. However, both NPV and Bt-based products caused low mortality of third-instar larvae and did not kill older larvae. The IGR lufenuron was highly effective against all three ages of larvae tested, whereas teflubenzuron and triflumuron produced maximum 60% mortality of second-instar larvae and lower than 50% to older larvae. Thiodicarb, chlorantraniliprole, indoxacarb, chlorpyrifos, and chlorfenapyr, irrespective of tested age, caused 100% mortality of larvae, with the last two insecticides reaching 100% mortality within 2 d of feeding on the treated diet. Flubendiamide caused lower mortality but significantly affected the weight of surviving larvae, whereas neither spinosad nor methomyl produced significant mortality or affected the weight of larvae. Based on the results, the age of H. armigera larvae plays an important role in the recommendation of NPV and Bt insecticides. Furthermore, there are potential options between biological and synthetic insecticides tested against H. armigera, and recording larval size during monitoring, in addition to the infestation level, should be considered when recommending biological-based insecticides to control this pest.