Assessment Of Insecticidal Effectiveness Of Selected Crude Plant Extracts On The Tomato Leaf Miner, Tuta Absoluta (Meyrick) (Lepidoptera: Gelechiidae)

ABSTRACT

Effects of Commiphora swynnertonii, Synadenium glaucescens and Allium sativum ethanolic extracts on the tomato leaf miner, Tuta absoluta Meyrick were evaluated under laboratory and screen house conditions. The threes life stages (eggs, second instar larvae and adults) of the tomato leaf miner were involved in the experiment. All the life stages of tomato leaf miner were treated topically with the plants extracts at (2%, 4% and 8%). The mean percentage mortality of eggs, second instar larvae and adults were recorded daily for 5 days. Results indicated that, each plant extract caused significant mortality to larvae and adults of T. absoluta after 5 days in comparison to the control. In laboratory, using the leaf dipping technique, Commiphora showed the highest effects on T. absoluta second instar larvae while Synadenium extract exhibited the least effect. The Commiphora ethanolic extract was the only one that showed potential to be used as a control agent against eggs as it led to 0% egg hatchability. Synadenium resulted in no mortality of T. absoluta eggs in this trial as there was 96.6% hatchability. Leaf dipping against second instar and adult of T. absoluta proved to be the most effective for all plants extracts at 30-100%. Commiphora resulted in the highest second instar larval and adults’ mortality of 100%. In the screen house Commiphora showed the high reduction of infestation for Tanya and Cal J varieties. Treatment with this plants extracts resulted in the highest fruit yield and the lowest yield loss compared to all the plant extracts. Commiphora swynnertonii extract is recommended into integrated pest management strategies for the control of T. absoluta.