In field and laboratory evaluations Cenicaña has found high percentages of parasitism in all species of the pest, which demonstrates its efficiency as a biological controller in sugarcane crops in the region.
With the purpose of incorporating new natural enemies that help regulate the cane borer Diatraea spp. and complement the biological control that is carried out with flies in crops of the region, Cenicaña advances studies with the wasp cotesia flavipes, with very good results.
According to the entomologist of Cenicaña, Dr. Germán Vargas, in the seventies the sugar agribusiness introduced to Colombia this wasp, originally from India, for the management of borers Diatraea. At that time there was no good adaptation of this natural enemy to the conditions of the Cauca River Valley and, therefore, research efforts were concentrated on tachytin flies and wasps Trichogramma.
With the recent outbreak of the plague the investigation was resumed with cotesia and the results both in the field and in the laboratory are showing their efficiency in all the borer species present in the region: D. indigenous, D.busckella, D. tabernella y D. saccharalis.
The results
In laboratory evaluations cotesia flavipes managed to parasitize all species of Diatraea, with a range of parasitism between 68% (D.busckella) and 92% (D.indigenella).
In fields with high infestation of Diatraea tabernella, in the north of the Cauca river valley, a parasitism of 61% was found in the plots where wasp releases were made and this resulted in a reduction of up to 65% of the damage caused by the borer.
According to Dr. Vargas, these results demonstrate the importance of incorporating the wasp into biological control programs of Diatraea, as a complement to the use of flies and wasps Trichogramma exiguum, widely used in the region's crops.
Cenicaña's research advances in studying the adaptation of the parasitoid in the different areas of the region and in promoting its use by mills and farmers. In addition, it is studied how to optimize its use in relation to other natural enemies, this in relation to the times and doses of release in the field.
KEEP IN MIND
The bees cotesia flavipes They are available in commercial laboratories present in the region.
Wasp female Cotesia flavipes parasitizing a larva of Diatraea saccharalis. “When at the end of 2012 and 2014 we detected two new species of the borer in the Risaralda mill Diatraea (D. tabernella y D.busckella) more aggressive than D.sacharalis the need arose to have new parasites that contribute to the reduction of damage levels. For that reason, when cotesia flavipes showed high levels of parasitism, we included it in our current management package and until today we have achieved sustainability in the percentage of infestation intensity. However, we continue working to reduce levels to less than 2,5% (level of economic damage). ”
Elizabeth Christina Molina
Chief of Agronomy Ingenio Risaralda
