Compatibility of a natural enemy, Coleomegilla maculata lengi (Col., Coccinellidae) and four insecticides used against the Colorado potato beetle (Col., Chrysomelidae)

• Published in: Journal of applied entomology (1986) Vol. 128; no. 3; pp. 233 - 239
• Main Authors: Lucas, É., Giroux, S., Demougeot, S., Duchesne, R.-M., Coderre, D.
• Format: Journal Article
• Language: English
• Published: Berlin, Germany Blackwell Verlag GmbH 01.04.2004; Blackwell
• Subjects: Bacillus thuringiensis; Bacillus thuringiensis subsp. tenebrionis; Biological and medical sciences; Biological control; biological control agents; Chrysomelidae; Coccinellidae; Coleomegilla maculata; Coleomegilla maculata lengi; Control; cryolite; cyromazine; developmental stages; Fundamental and applied biological sciences. Psychology; imidacloprid; Leptinotarsa decemlineata; mortality; nontarget organisms; Phytopathology. Animal pests. Plant and forest protection; predatory insects; Protozoa. Invertebrates; topical application; toxicity; Chrysomelidae; Coleoptera; Toxicity; Insecta; Bacillus thuringiensis; Systemic; Bacillaceae; Bacillales; Leptinotarsa decemlineata; Foliage; Bacteria; Developmental stage; Biopesticide; Coleomegilla maculata; Egg; Mortality; Insect growth regulator; Contamination; Recommendation; Prey; Coccinellidae; Lethal dose 50; Larva; Arthropoda; Cyromazine; Predator; Invertebrata; Compatibility; Microbial insecticide
• ISSN: 0931-2048; 1439-0418
• DOI: 10.1111/j.1439-0418.2004.00843.x

:   The toxicity of four insecticides used to control the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), imidacloprid (Admire®), cryolite (Kryocide®), cyromazine (Trigard®), and Bacillus thuringiensis var. tenebrionis (Novodor®), to one of its natural enemies, the 12‐spotted lady beetle, Coleomegilla maculata lengi Timberlake (Coleoptera: Coccinellidae) was determined in the laboratory. Toxicity assays against C. maculata adults and larvae consisted of (1) topical applications and (2) exposures to treated foliage and prey, using concentrations up to 10 times the manufacturer's recommendations. Over a 6‐day period, cyromazine (insect growth regulator) and B. t. var. tenebrionis (microbial insecticide) had no lethal effects on first and third instars C. maculata. For both larval and adult stages, cryolite (inorganic insecticide) caused very low predator mortality when topically applied and moderate mortality when ingested through contaminated eggs of Colorado potato beetles. Imidacloprid (systemic organic insecticide) was highly toxic to adult and larval C. maculata. Its estimated LD50 at 6 days following treatment, corresponded to 0.02–0.09 times the recommended field concentration, depending on the developmental stage and mode of contamination. These results indicate that integrated pest management programmes for Colorado potato beetles using imidacloprid or, to a lesser degree, cryolite, would be detrimental to C. maculata. Cyromazine and B. t. var. tenebrionis seem to present a better compatibility with the protection of C. maculata populations.