New structures for goat corrals to control peridomestic populations of Triatoma infestans (Hemiptera: Reduviidae) in the Gran Chaco of Argentina

David Eladio Gorla,Maria Laura Hernandez,Hugo Americo Hrellac,Ximena Porcasi,Silvia Susana Catala,Hugo Carrizo,Luciana Abrahan

doi:10.1590/s0074-02762013000300014

Abstract

Goat production is an important economic activity for rural communities in the Gran Chaco of Argentina. Goat corrals are important for the survival of peridomestic populations of Triatoma infestans. This study evaluated the impact of modifying the traditional structure of goat corrals on T. infestans populations and goat productivity in the region of Los Llanos (La Rioja). Thirty-nine experimental corrals were constructed and 57 traditional corrals were used as controls. We evaluated the infestations of the control and experimental corrals for five years following construction of the structures. The results showed that the new structures did not prevent the colonization, although it enhanced the detection of infestation at low densities of T. infestans. No significant difference was found in T. infestans population abundance between control and experimental corrals, probably because of the different detectability in the two types of structures, especially among the small nymphs. Although goat productivity average was higher in experimental than in control corrals, no significant difference was found because of high variability. The new structures can be used as a complement to promote the development of rural communities. Acceptability and adoption of the new corrals by the owners was high, as the enclosures offered better protection for the goats, increased growth of kids and facilitated herd handling.

Highlights

Goat breeding is one of the most important activities for the domestic economy of rural communities in the semi-arid Chaco
Peñaloza study sites - Infestation by T. infestans of control and experimental units - The entomological evaluation conducted before the construction of the new corrals showed that all traditional corrals assigned either to the control or experimental group were positive for T. infestans
By April 2006, 15 new corrals were finished. Ten of these corrals were colonised by T. infestans; two new corrals had a high abundance of the insects and eight new corrals had a medium or low abundance of the insects

Summary

Introduction

The lower section of the corral walls that are in contact with goat droppings (especially in the kid area) is the place where the abundance of T. infestans populations is highest Efforts to eliminate these populations using traditional vector control interventions, through professional or community-based pyrethroid insecticide applications, decreased the abundance of T. infestans populations, but did not eliminate the population. The environmental manipulation approach of changing the structure of the goat corral for the elimination of peridomestic populations of T. infestans was explored in the region of Los Llanos. The study tested the hypothesis that a procedure that decreases the likelihood of corral colonisation by T. infestans and simultaneously increases the number and unit value of the kids would be more attractive to the goat owners than a procedure that only decreases the likelihood of colonization

Methods

Results

Conclusion