Seedcorn Maggots (Diptera: Anthomyiidae) and Slugs in Conservation Tillage Systems in Ohio

Abstract

Seedcorn maggot, Delia platura (Meigen), adults and slugs were sampled from three tillage systems (conventional, reduced, and no tillage). There was a trend for more adult seedcorn maggots to emerge from reduced- and conventional-tillage systems than from the no-tillage system. Previous crop history influenced numbers of adults emerging, with more flies collected when the previous crop was soybeans rather than corn. Soil insecticide (phorate) application increased numbers of seedcorn maggots 1 yr and reduced them 1 yr. Based on data from this study, seedcorn maggots are not likely to be a problem in conservation-tilled fields where only soybean or corn residue is present. Slug populations were highest in no-tillage systems where crop residue cover was greatest and lowest when no residue was present. There was a trend for numbers of slugs to be greater when the previous crop was soybeans; this is thought to be related to either the increased amount of dead, weed biomass present or a preference for decomposing soybean tissue in the no-tillage system. Slug problems are expected to increase as conservation tillage becomes more common because of the residue cover and inclusion of soybeans in no-tillage rotational systems.