Explorando o potencial de Doru luteipes (Dermaptera: Forficulidae) como predador e sua atuação sobre Spodoptera frugiperda

Abstract

Doru luteipes (Scudder, 1876) (Dermaptera: Forficulidae) is the most commonly observed predator in Brazilian maize crops, present in all main producing regions. In the crop, the earwig is considered an important natural enemy of lepidopteran insects, such as Spodoptera frugiperda (Smith, 1797) and Helicoverpazea (Boddie, 1850) (Lepidoptera: Noctuidae), of which it preferentially feeds on the eggs and neonate caterpillars, as well of different aphid species. D. luteipes has an omnivorous habit, feeding on corn pollen and fungal spores, which allows it to remain in the field even when there is low prey availability. Several researches have been conducted in the last three decades, exploring the predatory potential of this earwig and evaluating the selectivity of the main insecticides used in the management of insect pests that occur in the crop. However, information about its role as a natural enemy is still very scarce and scattered. Furthermore, even though the occurrence of D. luteipes in the field is directly related to the population reduction of the fall armyworm, several aspects of its predatory activity have not yet been studied. In this work, we developed a review article aiming to gather information about the role of D. luteipes as a natural enemy of agricultural pests and stimulate the development of new works. We investigated aspects of D. luteipes action on S. frugiperda that were little explored until now, such as non-consumption or non-lethal effects on moths, the predatory preference between eggs and neonates, the functional response on eggs and attraction to volatiles from egg and neonate-infested plants. Additionally, we evaluated the attraction of D. luteipes to volatiles from maize plants attacked by Rhopalosiphumpadi (Linnaeus, 1758) (Hemiptera: Aphididae), seeking to analyze its potential in locating aphids in the field. S. frugiperda moths deposited a smaller number of eggs on plants with the previous presence of earwigs, indicating that the early occurrence of this predator in the field may difficult pest colonization. The earwig prefers to feed on fall armyworm eggs, and males and females showed a type II functional response, but males perform better when exposed to higher egg densities. Thus, D. luteipes males and females efficiently search for and consume their preferred prey and the increase in population density of both would be favorable to S. frugiperdabiological control. Female earwigs are strongly attracted to plants damaged by neonate caterpillars, however, they do not respond to volatiles from plants infested by R. padi adults. These findings add knowledge about D. luteipes predatory activity and expand the perspectives for future studies aimed at favoring the occurrence and activity of this notable natural enemy.