Biological Control of Exotic Andean Solanaceous Fruits
The demand for solanaceae fruits such as tree tomato (Solanum betaceum) and lulo or naranjilla (Solanum quitoense) has increased, especially for fresh consumption. The exclusive flavor of these fruits also attracts attention in international markets such as Japan, the United States and Europe. In Colombia, Venezuela and Ecuador, the tomato fruit borer, N. elegantalis (Lepidoptera: Crambidae), is the most important pest and, together with fungal diseases, are responsible for the use of significant amounts of agrochemicals for its control.
Biological control is an alternative measure –with good success possibilities- since these fruit trees are semi-perennial, which would facilitate the establishment of parasitoids. An adequate population management program for the insect must consider basic studies that allow knowing with certainty the insect's different ecological relationships with the host plant, natural enemies, and the environment. This was the central premise of the project.
The project faced important challenges such as the unexpected departure of Venezuela and the incorporation of Ecuador, as well as climatic conditions that made it difficult for symptoms to appear or for the effective establishment of the proposed biological controllers. Despite this, the knowledge generated was significant and provided clear guidelines for the design of biological and ethological control programs for N. elegantalis with solid scientific bases.
The technological solution
The technological solution achieved was the development of protocols, methodologies and technologies for the biological control of the main pest (fruit borer) that attacks the tree tomato (Solanum betaceum) and lulo or naranjilla (Solanum quitoense) in the Andes. The use and abuse of chemical products, until now the common practice, has negative effects on the environment, the cost of production and, most importantly, it puts a barrier to the export of these products to North America and Europe that demand high quality fruits.
The solution considered collecting and characterizing potential biocontrollers, insect morphological and molecular analyzes, and the use of pheromones to differentiate biotypes, as well as methods to propagate parasitoids for subsequent release. Finally, plants associated with the two species of interest were identified to facilitate the parasitic action of biocontrollers.
The project laid the foundations for effective biological control of the N. elegantalis fruit borer, an insect that causes considerable damage and loss in the production of tree tomato and lulo or naranjilla. Specific achievements included collections of potential biocontrollers; morphological and molecular analysis and charactrerization of N. elegantalis and the use of pheromones to verify differences between insect biotypes.
Additionally, after an analysis of options, the methodology for the mass production of Lixophaga sp. Was developed as the most appropriate to use in Solanum quitoense. In parallel, plants associated with the two species of fruit trees were identified in order to facilitate the parasitic activity of the natural enemies of N. elegantalis.
The project generated significant production of technical and scientific articles, a chapter in a book, and capacity building in biological control in Colombia and Ecuador.
The project did not report a quantification of direct and indirect beneficiaries. However, the number is likely significant in particular technicians, specialists, students and producers associated with the different actions of the project.
Sustainable Development Goals
- Corporación Colombiana de Investigación Agropecuaria (CORPOICA) - Colombia
- International Center for Tropical Agriculture (CIAT) - Colombia
- MIZA - UCV - Venezuela