Lethal and sublethal effects of calcium carbonate formulation against fall armyworm, Spodoptera frugiperda

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an important insect pest of maize (Zea mays L., Poaceae). The use of synthetic insecticides to control this pest remains the most popular option amongst growers. Natural insecticides offer a safer alternative to synthetic insecticides for controlling FAW. This study aimed to investigate the lethal and sublethal effects of a calcium carbonate formulation against this invasive insect pest. The tested formulation was a mixture of calcium carbonate (five concentrations), wetting agent and dispersant agent. Four experiments were conducted including a direct contact test, a no-choice feeding test, a choice feeding test and an oviposition test. The application of the calcium carbonate formulation on maize leaves had a strong anti-oviposition effect for adult female FAW, but a low-to-moderate antifeedant effect on FAW larvae. The growth and development of FAW larvae were only slightly affected by the calcium carbonate formulation in the feeding and the direct contact tests. The lethal effects of the calcium carbonate formulation against FAW larvae were low in direct contact and feeding tests. These results indicate that a calcium carbonate formulation has the potential to be used as the push component in a push–pull strategy for FAW control. Considering its low toxicity, both through direct contact and feeding, calcium carbonate can be an environmentally friendly alternative for the management of FAW.