Attraction and oviposition responses of Phthorimaea absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae) females to different tomato varieties

The tomato leafminer, Phthorimaea absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), is currently the major pest threatening cultivated tomato production worldwide, causing severe yield losses. This study focused on investigating the effects of the five tomato varieties (Taykan, Torry, Verty, Seyran, and Mamston) most preferred by producers in Antalya province in Türkiye on the attraction and oviposition responses of P. absoluta females. Y-tube olfactometer bioassays were conducted to determine the attraction of tomato varieties to mated P. absoluta females. Oviposition preference bioassays were carried out in cages to establish the effect of tomato varieties on the pest’s oviposition response. Volatile organic compounds of each variety were also identified by GC-MS. Mated P. absoluta females were most attracted to the Taykan variety and least attracted to the Mamston variety in the Y-tube olfactometer. In the oviposition choice and no-choice experiments conducted in cages, mated females laid the highest average number of eggs on Taykan (92.70 ± 4.02 and 84.40 ± 3.14, respectively) and the lowest on Mamston (41.30 ± 3.95 and 39.80 ± 3.08, respectively), with a statistically significant difference observed. In GC-MS, the most abundant compounds identified in all varieties were terpenes, followed by aldehydes. Principal component analysis on volatile organic compounds from tomato varieties revealed a 71.25% variance between varieties by two components. The presence of VOCs, namely caryophyllene, humulene, 2-carene, beta-phellandrene, and o-cymene could serve as attractant to mated P. absoluta females, whereas the presence of (E)-2-hexenal, hexadecane, nerone, and mequinol could have a repellent effect. Consequently, this study showed that tomato varieties significantly influenced female tomato leafminer attraction and oviposition responses. Accordingly, the findings presented herein may prove beneficial in the development of tomato varieties resistant or tolerant to P. absoluta.