Chlorpyrifos spraying of no-tillage corn during tasselling and its effect on damage by Helicoverpa zea (Lep., Noctuidae) and on its natural enemies

• Published in: Journal of applied entomology (1986) Vol. 126; no. 7-8; pp. 422 - 430
• Main Authors: Filho, M. M., Della Lucia, T. M. C., Cruz, I., Guedes, R. N. C., Galvão, J. C. C.
• Format: Journal Article
• Language: English
• Published: Berlin, Germany Blackwell Verlag GmbH 01.09.2002; Blackwell
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Chemical control; Control; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Fundamental and applied biological sciences. Psychology; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; South America; Brazil; America; Monocotyledones; Insecticide; Trichogramma pretiosum; Insecta; Tropical zone; Non target effect; Zero tillage; Cereal crop; Heteroptera; Pest; Entomophagous; Pest management; Gramineae; Beneficial animal; Helicoverpa zea; Chalcidoidea; Angiospermae; Trichogrammatidae; Emergence; Chemical control; Parasitism rate; Damage; Chlorpyrifos; Zea mays; Ecotoxicology; Spraying; Pesticides; Spodoptera frugiperda; Orius; Parasitoid; Anthocoridae; Arthropoda; Lepidoptera; Organophosphorus compounds; Spermatophyta; Noctuidae; Predator; Hymenoptera; Invertebrata; Infestation; Non target organism
• ISSN: 0931-2048; 1439-0418
• DOI: 10.1046/j.1439-0418.2002.00683.x

:  Corn plants were twice sprayed at 3‐day intervals during tasselling to evaluate the effect of chlorpyrifos on ear damage by H. zea and also on the populations of the natural enemies associated with this moth. The abundance of H. zea eggs and larvae and of predators on the whole plant, the egg parasitism by Trichogramma pretiosum Riley and the percentage of injured ears were sampled weekly. Chlorpyrifos did not show any significant effect on population levels and on ear damage by H. zea. Natural parasitism of eggs ranged from 52 to 75% and did not differ between treated and untreated plots; furthermore, the percentage of non viable eggs and adult emergence were not influenced by insecticide application. Among the predators found in the plots, Doru luteipes was not affected by spraying, whereas the abundance of Orius sp. decreased 21 days after insecticide application. The frequency of the ant Pheidole sp. was not affected by chlorpyrifos; however, foraging activity of Crematogaster sp. on treated plots was rapidly reduced and remained low during the following 2 weeks. The small number of damaged ears suggests that the insecticide did not affect the efficiency of the natural enemies of H. zea.