Biological Control of Tuta absoluta in Saudi Arabia: A Promising Organic Strategy Using Entomopathogens

Author : Mohamed Baha Saeed, Abdulaziz M Alnasser, Nasser I Alaruk, Abdulrahmn A Algrwai, Salman A Aloudah and Sultan M Al Eid

Abstract :Tuta absoluta (Meyrick) is a damaging pest of tomato, with soil stages that are difficult to control using typical insecticides. This research tested two local biocontrol agents, Beauveria bassiana (strain NOAC.F7) and Heterorhabditis indica (strain NOAC.N8), applied alone or in sequence as soil drenches against the fourth larval stage of T. absoluta in greenhouse conditions. B. bassiana was tested at 2×10^8 and 2×10^9 spores/ml, while H. indica was applied at 100 and 150 IJs/cm². Sequential treatments involved B. bassiana followed by H. indica after 24 or 48 hours. The experiment used a randomized complete block design with three replicates, and adult emergence was measured. In the control, adult emergence was 100%. Single applications of either B. bassiana or H. indica moderately reduced pest emergence, to about 48–52%. Sequential treatments improved control, lowering adult emergence to 42 47%. While differences between the 24-hour and 48-hour intervals were not statistically significant, a slightly better suppression was observed with the earlier application of the nematodes. Overall, combining fungal and nematode biocontrol agents provided better control of T. absoluta than using either alone. These findings suggest that combining B. bassiana (NOAC.F7) with H. indica (NOAC. N8) could be an effective and environmentally friendly strategy for managing the fourth larval stage of T. absoluta in greenhouse tomato cultivation.

Keywords :Biocontrol, Tuta absoluta, Heterorhabditis indica, Beauveria bassiana, Tomato, Greenhouse.

Conference Name :International conference on agriculture and biological sciences (ICOABS-25)

Conference Place Taif,Saudi Arabia

Conference Date 19th Nov 2025