Evaluation of Doru lineare (Dermaptera: Forficulidae) effectiveness against Spodoptera frugiperda (Lepidoptera: Noctuidae) and its potential protection of maize seedlings

The “fall armyworm”, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a significant pest of many crops, particularly maize. To control it, genetically modified plants and synthetic pesticides are the main strategies employed, which has led to the emergence of resistant populations to both methods. The earwig Doru lineare (Eschscholtz) (Dermaptera: Forficulidae) has been observed in Argentina consuming both eggs and early instars S. frugiperda larvae. To contribute to the implementation of a rational pest management system, field cage tests were conducted to assess the efficiency of D. lineare as a predator against S. frugiperda and its potential protection of maize seedlings from the pest. The results of the tests showed that the survival rate of S. frugiperda larvae was significantly affected by the presence of earwigs. When two earwigs were released into a cage containing ten maize seedlings infested with twenty S. frugiperda larvae, after ten days, the dry weight of the plants was significantly higher and the level of damage was significantly lower compared to those without earwig release. These results confirm the protective effect of D. lineare against S. frugiperda, suggesting that earwigs should be considered as promising predators in conservation control strategies for maize crops.