Population density of Tibraca limbativentris on flood irrigated rice and alternative host plants

Mauricio Paulo Batistella Pasini,Ana Lúcia De Paula Ribeiro,João Fernando Zamberlan,Alessandro Dal’Col Lúcio,Sidinei José Lopes,Alberto Cargnelutti Filho

doi:10.1590/s0100-204x2018000300001

Mauricio Paulo Batistella Pasini, Ana Lúcia De Paula Ribeiro + Show 4 more

Open Access

https://doi.org/10.1590/s0100-204x2018000300001

Copy DOI

Abstract

Abstract: The objective of this work were to evaluate the population dynamics of the rice stem bug (Tibraca limbativentris) around and in flood irrigated rice cultivation area, to quantify the insect population flow between crops and host plants, and to determine the effect of the species, the diameter of the plant, and the distance of the host plant from the border on the rice stem bug population. The work was conducted in the 2012/2013 harvest and in the off-season, with sampling of rice, Andropogom bicornis, and Andropogon lateralis plants in six cultivated areas, in order to count the number of insects. The population density of the rice stem bug in irrigated rice and alternative host plants presents spatial and temporal dependence. In the cultivated areas, the population density of the rice stem bug increases according to the evolution of the rice phenological stages, with the highest densities concentrated in regions close to the crop borders. The diameter and species of the host plant affect the rice stem bug population. Andropogon bicornis plants have higher population densities than A. lateralis, and plants with larger diameters show higher population densities of the rice stem bug. In the off-season, the greatest population of the rice stem bug on host plants is concentrated up to 45 m from the crop border, but it can disperse until 150 m.

Highlights

The rice stem bug [Tibraca limbativentris Stål 1860 (Hemiptera: Pentatomidae)] is one of the main pests of the rice (Oriza sativa L.) crop with major importance for irrigated rice (Machado et al, 2014)
The experiment was performed in the municipality of Santa Maria, in the state of Rio Grande do Sul, Brazil (785108 m; 6716393 m, 21J, UTM), in six flood irrigated rice crops with areas between 0.25 and 14.1 ha (Figure 1), cultivated according to the technical recommendations for the culture (Reunião Técnica da Cultura do Arroz Irrigado, 2014), but without the application of chemical pesticides
In alternative host plants, the population showed a behavior contrary to that observed in the cultivated areas

Summary

Introduction

The rice stem bug [Tibraca limbativentris Stål 1860 (Hemiptera: Pentatomidae)] is one of the main pests of the rice (Oriza sativa L.) crop with major importance for irrigated rice (Machado et al, 2014). The damage caused by this insect produces two symptoms: white panicle and dead heart, with direct interference on yield and damages that are proportional to its population density. In the off-season, these insects look for alternative habitats around the cultivated areas to find shelter, where they remain in quiescence (Medeiros & Megier, 2009; Smaniotto & Panizzi, 2015). Quiescent adults leave their shelter in late September and early October, when they seek host plants and copulate (Ferreira et al, 1997). With the sowing of rice and seedling emergence, the bugs migrate to the crops and continue their physiological activities until harvest, after which they migrate to the surroundings of the cultivated areas (Klein et al, 2012; Awuni et al, 2015)

Objectives

Methods

Results

Conclusion