Selective effects of natural and synthetic insecticides on mortality of Spodoptera frugiperda (Lepidoptera: Noctuidae) and its predator Eriopis connexa (Coleoptera: Coccinellidae).
Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is a serious pest of corn in several American countries. It is mainly controlled with synthetic insecticides. The objectives of this study were to evaluate the effects of the natural products, neem oil and pyroligneous extract, and the synthetic insecticide, lufenuron, at 2.50 mL water (0.25%) on the mortality of 2-, 4- and 6-day-old caterpillars of S. frugiperda, and their selectivities against fourth instar larvae of Eriopis connnexa Germar (Coleoptera: Coccinellidae). Four- and 6-day-old S. frugiperda caterpillars showed higher mortality after exposure to neem oil (83.33 +/- 0.83 and 89.58 +/- 0.90%, respectively) and lufenuron (95.83 +/- 0.96 and 85.41 +/- 0.83%), compared to pyroligneous extract (68.75 +/- 0.69 and 31.25 +/- 0.31%). The deleterious effect of pyroligneous extract was higher in 2- (83.33 +/- 0.83% mortality) and 4-day-old (68.75 +/- 0.69%) S. frugiperda caterpillars than in 6-day-old caterpillars (31.25 +/- 0.31%). Larval mortality of the predator E. connexa was lower with neem oil and pyroligneous extract (25.00 +/- 0.33%) than with lufenuron (91.66 +/- 1.22%). Neem oil is thus recommended for control of S. frugiperda because of its high toxicity, combined with its relatively low toxicity to larvae of the natural enemy E. connexa.
Tavares
Wagner S
WS
Departamento de Fitotecnia, Universidade Federal de Vicosa, Vicosa, Minas Gerais State, Brazil.
Costa
Mariana A
MA
Cruz
Ivan
I
Silveira
Rodrigo D
RD
Serrao
Jose E
JE
Zanuncio
Jose C
JC
D000818:Animals; D001549:Benzamides / Q000737:chemistry / Q000633:toxicity*; D001681:Biological Assay; D001688:Biological Products / Q000737:chemistry / Q000633:toxicity*; D001938:Brazil; D001517:Coleoptera / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D005989:Glycerides / Q000737:chemistry / Q000633:toxicity*; D007306:Insecticides / Q000138:chemical synthesis / Q000737:chemistry / Q000145:classification / Q000633:toxicity*; D011235:Predatory Behavior; D018411:Spodoptera / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D015996:Survival Rate; D013729:Terpenes / Q000737:chemistry / Q000633:toxicity*; D013997:Time Factors; D003313:Zea mays / Q000469:parasitology; D005466:Fluorocarbons
D001549:Benzamides; D001688:Biological Products; D005989:Glycerides; D007306:Insecticides; D013729:Terpenes; C070364:fluphenacur; D005466:Fluorocarbons; C002443:neem oil