Legume-based intercropping for the management of fall armyworm, Spodoptera frugiperda L. in maize

Fall armyworm, Spodoptera frugiperda (Noctuidae: Lepidoptera), is an economically important invasive pest infesting maize. Habitat manipulation as a method of conservation biological control which employs cover crops/hedge rows/flower strips crops in the main crop field to conserve the beneficial insect fauna like natural enemies. An experiment was conducted to study the influence of intercropping of leguminous crops in maize for the management of fall armyworm. Five treatments viz., maize + groundnut (Arachis hypogaea), maize + broad bean (Vicia faba), maize + (Desmodium sp), maize + soybean (Glycine max) and monocrop of maize were evaluated for the severity of damage caused by fall armyworm. The percent plant damage and number of live larvae per 25 plants were significantly less in the maize + Desmodium sp at 9 weeks after planting compared to the monocrop of maize. Significantly higher rates of parasitization of egg mass of fall armyworm by Trichogramma sp were recorded in the maize + broad bean compared to the monocrop of maize. The abundance of Coccinellid predators and geocorid bugs was significantly higher in maize intercropped with groundnut compared to the sole crop of maize. The results of the study indicated the definite role of maize-legume intercropping in reducing fall armyworm damage in maize.

Automated summary

The study showed that intercropping maize with Desmodium sp significantly reduced plant damage and number of larvae per 25 plants at 9 weeks after planting. Higher parasitization rates of fall armyworm egg masses by Trichogramma sp were observed in maize intercropped with broad bean compared to monocrop maize. Additionally, there were significantly more Coccinellid predators and geocorid bugs in maize intercropped with groundnut than in sole maize crop.