Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Attraction of female tomato leaf miner, Tuta absoluta (Meyrick, 1917) (Lepidoptera:Gelechiidae) to shared compounds from hosts.

Abstract

Tomato leaf miner, Tuta absoluta is a ravaging pest of tomato in many countries of the world including Tanzania. The pest inflicts substantial damage to tomato crop that causes a huge loss to farmers. This study focused on evaluating potentials of shared volatiles emanated from four hosts of the pest, namely tomato, aubergine, sweet pepper and watermelon in formulating attractant for female T. absoluta. Y-tube olfactometer was used to evaluate attractiveness of leaf volatiles from four hosts and a blend of shared compounds and GC-MS was used to identify volatile constituents of the four hosts. Results indicate that, female T. absoluta were attracted to volatiles of tomato volatiles (χ2 = 4.9, P < 0.05) and repelled by watermelon volatiles (χ2 = 6.4, P < 0.05). We further observed high composition of terpenes in tomatoes (70%) as compared to other hosts, which might have contribute to its observed attraction compared to the other hosts. On the other hand, watermelon was highly constituted by green leaves volatiles (GLVs) which is suggested to account for the observed repellency. Thus, shared compounds that do not contain GLVs significantly attracted female T. absoluta at a dose of 10 μl (χ2 = 8.1, P < 0.05). Our findings have revealed that, compounds shared by hosts attract females T. absoluta. Therefore, results from this study have laid groundwork in the development of attractant for management and monitoring of the pest.