Ants (Hymenoptera: Formicidae) increase predation of Belenois solilucis (Lepidoptera: Pieridae) eggs in organic agriculture production systems: a multiple-site field study at Rashad, Sudan

Abstract

Organic farming is becoming more popular as there is a greater demand for pesticide-free food. Pest control in organic agricultural production requires a set of skills, including the identification of effective predators and land-use practices. Predation by selected Coleopteran, Dipteran, and Hemipteran insects and Araneae is well established, whereas the predatory role of ants (Hymenoptera: Formicidae) has received little attention in the Rashad district, Sudan. This study was carried out to assess the predation rates of Belenois solilucis eggs and the impact of the land use type around the properties on these rates. An experiment involving predation tests on Belenois solilucis eggs and fauna sampling were conducted in 18 areas of organic agriculture in the Rashad district. The study showed that ants can reduce the eggs population by 26.8% per day. At the same time, other predator taxa, primarily Coleoptera, from Coccinellidae and Staphylinidae families, removed only 13% of the eggs. Ant species with the most significant recruiting power were Axinidris acholli, Tapinoma carininotum, and Technomyrmex moerens. Ant genera such as Linepithema, Dorymyrmex, and Camponotus ants were also frequently observed. The proportion of the planted area within a 500-meter radius, in addition to the interaction of other landscape categories, had a minor influence on predation, but only when the predators were not ants. The landscape does not affect predation by predators in general, including ants, or on ant predation in particular.