Natural Biological Control of Lepidopteran Pests by Ants

Abstract

The predatory ants (Hymenoptera: Formicidade) are social insects and important natural enemies of pests in agroecosystems. Despite the importance of these predators, little is known about their role, especially in tropical regions. Among the major Lepidopteran pests of vegetables are Ascia monuste (Pieridae), Diaphania nitidalis (Crambidae), Neoleucinodes elegantalis (Crambidae) and Tuta absoluta (Gelechiidae). Thus, this work aimed to study the natural biological control of A. monuste, D. nitidalis, N. elegantalis and T. absoluta by ants. For this, we evaluated the natural biological control of A. monuste on kale and D. nitidalis on cucumber both species in the dry season. Whilst the natural biological control of N. elegantalis and T. absoluta on tomato plants were evaluated in the rainy and dry seasons. Ants preyed on Lepidoptera in the pupa stadium. They also preyed on eggs of D. nitidalis. The activity of predatory ants occurred mainly during the night. The ants were the main causes of pupae mortality of A. monuste, D. nitidalis and T. absoluta. Beyond the ants, the physiological disturbances and birds were also important factors of pupae mortality of N. elegantalis. The ants Labidus coecus and Solenopsis sp. were observed preying on pupae whereas the Paratrechina sp. was observed preying eggs of D. nitidalis. The pupae mortality of D. nitidalis and T. absoluta by ants were higher than the pupae mortality of N. elegantalis and A. monuste. The rate of pupae predation of N. elegantalis by ants was similar in rainy and dry seasons and the same occurred with T. absoluta.