Effect of crop residue management on damage by Diatraea saccharalis (Lepidoptera: Crambidae), its egg parasitoids and the ants associated with sugarcane

Abstract

In the American continent, the sugarcane borer Diatraea saccharalis (F.) is the main pest in sugarcane producing areas. The objective of this study was to assess the effect of crop residue management on damage by D. saccharalis, its egg parasitoids and the ants associated with sugarcane. The study was carried out during 2011–2012, 2012–2013 and 2013–2014 crop cycles, in three commercial fields located in different regions of Tucumán state, Argentina. Two types of crop residue management (= treatments) were compared: conservation of trash at the soil surface (CT) and trash burning (TB). In ‘trash conservation’ treatment, crop residue was allowed to remain over the soil surface during the whole sugarcane growing season, while the second treatment consisted of complete burning of trash blanket approximately 2 weeks after harvest. The injury level was measured by recording the number of stalks bored and internodes bored. Parasitism was estimated by counting the total number of eggs and number of black eggs (which indicates the occurrence of egg parasitoids). Ants (Formicidae) richness was calculated by two estimators; abundance-based coverage estimator and incidence-based coverage estimator, using the non-parametric richness estimators: Chao 2 and Jackknife. Finally, the indicator value was estimated through the measurement of specificity and fidelity. In all the parameters studied no significant difference was found between TB and CT treatments.