Volatile chemical signals underlying the host plant preferences of Tuta absoluta

Abstract

The South American leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a serious pest of tomato causing substantial annual economic losses at a global scale. Our study comprised choice and no‐choice bioassays, aimed at understanding the preference of this oligophagous pest for a few selected solanaceous hosts (tomato, potato, eggplant, ashwagandha, black nightshade, wild tomato, tobacco, and datura), and the identification of the volatile cues that influence its host selection process. In choice assays, T. absoluta females preferred tomato for oviposition over all the other plants, whereas ashwagandha, tobacco, and datura were the least preferred; on datura zero eggs were laid. A similar trend was observed in the subsequent number of larval mines formed. The moth’s preference for host plants of the genus Solanum was quite evident in both the choice and no‐choice assays. Tomato plant volatiles were found to be more attractive to the female moths in single‐ and dual‐choice olfactometer assays. In electroantennographic bioassays, the mean depolarization was significant for tomato, potato, ashwagandha, and eggplant compared to empty air and honey. In total 76 volatile compounds were identified in the GC‐MS analysis across the eight previously selected host–plant headspace samples. Principal component analysis revealed that 1‐fluorododecane and p‐quinone mainly contributed to the observed variation among the host plant volatiles. Of all the host plants, tomato, wild tomato, and tobacco were found to share similarities with respect to volatile cues, whereas ashwagandha, eggplant, and datura were found to be closely related. The other two hosts, potato and black nightshade, had fewer volatiles in common. Volatile cues, namely p‐quinone, 2‐carene, δ‐curcumene, and 1,2‐diethylbenzene, in tomato could serve as oviposition stimulants to T. absoluta, whereas the presence of 1‐fluorododecane in host plants such as datura, eggplant, ashwagandha, and black nightshade, might have deterred T. absoluta from ovipositing. 1‐Fluorododecane was found to be completely absent in tomato.

Development of attractants and repellents for Tuta absoluta based on plant volatiles from tomato and eggplant

“…Specifically, 15 VOCs were highly accumulated in tomato, with alcohol and heterocyclic compounds the most abundant. These results were different from the previous study, which reported that tomato had a higher number of terpenes and acid compounds than other host plants (including eggplant) (Msisi et al, 2021;Subramani et al, 2021). Our results showed that 24 VOCs were accumulated higher in eggplant with aldehyde and heterocyclic compounds the most abundant.…”

“…Tuta absoluta is oligophagous and can survive and reproduce normally on potatoes, tobacco and other Solanaceae crops (Arnó et al, 2019). Nevertheless, it has been found that T. absoluta had a strong preference for tomatoes among host plants, and volatile chemical signals played important roles in its host plant preferences (Subramani et al, 2021). Similarly, in our previous study, it has been found that the number of eggs laid by T. absoluta was significantly higher on tomatoes than on eggplants (Chen et al, 2021).…”

Genomic and metabolic profiling of two tomato contrasting cultivars for tolerance to Tuta absoluta

“…All compounds identified in the present work are in accordance with literature data concerning the VOC released by tomato plants upon herbivore feeding (i.e. T. absoluta larvae) (Proffit et al 2011 ; Anastasaki et al 2015 , 2018 ; Catola et al 2018 ; Milonas et al 2019 ; Subramani et al 2021 ; Ayelo et al 2022 ; Deletre et al 2022 ; Miano et al 2022 ). In particular, we recorded a blend of volatiles emitted by tomato plants infested by Tuta larvae quantitatively different with respect to undamaged control plants as already reported (Anastasaki et al 2015 , 2018 ; Milonas et al 2019 ; Ayelo et al 2022 ).…”

Non-host plant odors influence the tritrophic interaction between tomato, its foliar herbivore Tuta absoluta and mirid predator Nesidiocoris tenuis

“…Our results indicate that adult females of T. absoluta are attracted to Solanaceae host plant volatiles but avoid host plant volatiles in the presence of the non-host Asteraceae plants marigold, blackjack, and the positive control, wild tomato. These results are consistent with the fact that olfactory cues play an important role in the host finding process of T. absoluta ( Desneux et al., 2010 ; Bitew, 2018 ; Subramani et al., 2021 ). Our findings corroborate results of a previous study ( Miano et al., 2022 ), which demonstrated the host disruption and masking role of the volatiles of the positive control, wild tomato in the host location process of T. absoluta in the presence of the host plant cultivated tomato.…”