Oviposition preference of tomato leafminer, Tuta absoluta (Lep: Gelechiidae) on different tomato genotypes

Abstract

Tomato leafminer Tuta absoluta Meyrick (Lep: Gelechiidae) is one of the most important pests affecting tomato cultivation in Iran. Given its wide spread distribution, it becomes necessary to apply an effective management method. The high damage inflicted by this pest on tomato crops has historically led farmers to use chemical pesticides for quick control, resulting, in pesticide overuse and the development of resistance, rather than effective control against the tomato leafminer. Planting resistant cultivars to agricultural pests considered as one of the most important strategies for the cost-effective production of healthy products and the reduction of pesticide consumption. This study investingates the egg laying preferences of T. absoluta on 15 different tomato genotypes resulting from the hybridization (crossing) of two commercial cultivars, Sakhiya and Eshkol, using a free choice test under greenhouse conditions. Additionally, trichome density and chlorophyll content were assessed in the studied genotypes. The results revealed that Eshkol 52-2 (2), Sakhiya 9-2 (3) and Sakhiya 8-2 (3) exhibited the highest rates of egg laying, while Eshkol 52-7(2) and Eshkol 52-4 (2) showed the lowest. Furthermore, the genotypes with higher egg-laying rates were associated with lower trichome density. However, the chlorophyll content in Eshkol 52-2 (2), which had the most egg-laying rate, was notably high. Conversely, Sakhiya 9-2 (3) and Sakhiya 8-2(3), which also demonstrated relatively high egg-laying rates, exhibited lower chlorophyll content. The chlorophyll content in the genotypes Eshkol 52-7 (2) and Eshkol 52-4 (2), was relatively low but also the egg laying rate was low.

Keywords

• trichome
• chlorophyll
• tomato genotype
• pest management