Nesidiocoris tenuis au Burkina Faso: Distribution, capacité de prédation et sensibilité aux insecticides

Tuta absoluta (Lepidoptera: Gelechiidae) is a worldwide invasive insect species, considered a major pest of tomato. It has recently established in Burkina Faso, where chemical control remains the only affordable option to limit damage. Nesidiocoris tenuis (Hemiptera: Miridae) is commercialised as a biological agent to control this pest in other parts of the world. But no literature is available on this predator in Burkina Faso.
Therefore, in this study, we (1) scoured the country to determine its distribution and abundance in tomato fields, (2) verified its ability to consume T. absoluta eggs in two scenarios: the first one where N. tenuis has to search for the eggs on the plants and the second one in Petri dishes where the eggs are placed and N. tenuis could consume the eggs at will (3) measure the susceptibility of both insects to insecticides (two synthetic insecticides, three bio-bacterial insecticides and eight plant extracts) using the IRAC 022 method.
It appears that, N. tenuis was found in 13 regions of the country with very interesting densities in some tomato fields (up to 80 individuals / m2).
All stages of N. tenuis consume T. absoluta eggs and the number of eggs consumed depends on the stage of development and mode of egg delivery. When he has to look for some on the leaves, the adults find about 20 eggs to consume per day, while for an availability and consumption at will of eggs, he consumes about 45 eggs per day.
Abamectin, emamectin benzoate, spinosad, spinetoram were very toxic for both T. absoluta and N. tenuis. In contrast, biopesticides including Bacillus thuringiensis, neem oil, Cleome viscosa, Ocimum basilicum and Cassia occidentalis were found to be compatible with N. tenuis while controlling T. absoluta.
Based on our results, we recommend that through training for growers, they can be shown the importance of N. tenuis in the management of T. absoluta. We therefore recommend the use of biopesticides in combination with N. tenuis in the control of T. absoluta in Burkina Faso.