1. Frequently changing climatic conditions can cause recurring droughts which often subject plants to tremendous amounts of stress, leaving biologists to wonder about its impact on the associated herbivores and their interactions with host plants. 2. The present study was aimed at assessing the impact of low moisture stress on herbivore‐plant interactions using tomato and its associated herbivores (leaf miner, Tuta absoluta and sap feeder, Bemisia tabaci). 3. The leaf miner T. absoluta preferred tomato plants exposed to moderate drought stress compared to severely drought stressed or healthy plants while the sap feeder B. tabaci preferred healthy tomato plants that were irrigated regularly over others. Our study uncovers few intriguing aspects of low moisture stress on herbivore‐host interactions and also highlights that this influence may vary depending upon the herbivore feeding guild. 4. The volatile profiles of tomato plants were found to differ significantly when subjected to varied degrees of low moisture stress. Such changes in plant's volatile emissions may in turn alter its associated herbivore's behavioural perspective as observed in T. absoluta and B. tabaci. 5. Reduced amounts of caryophyllene, humulene, 3‐carene, myristic acid, and γ‐butyl‐γ‐butyrolactone might be what aids T. absoluta and B. tabaci in gauging the drought stress status of a host plant. Further, the presence of chemical cues such as α‐pinene, m‐cymene, and ethyl benzaldehyde might signal T. absoluta moths of severely stressed plants. Similarly, the presence of undecane, ethyl benzaldehyde, n‐hexadecanoic acid might aid whiteflies in identifying plants reeling under low moisture stress.

South American tomato moth, Tuta absoluta, a serious pest of tomato (Solanum lycopersicum) in tropics and subtropics, is rapidly spreading world over. Twenty one wild/cultivated/advanced breeding lines of tomato were screened for resistance to T. absoluta under greenhouse conditions (choice bioassay) and promising genotypes were evaluated further for their antibiosis activity through no choice bioassay under in-vitro conditions. From 21 genotypes screened, six wild accessions viz., S. pennellii (LA 1940); S. chilense (LA 1963); S. arcanum (LA 2157); S. lycopersicum (LA1257) and S. corneliomulleri (LA 1292, LA1274) were relatively resistant to T. absoluta based on mean percent damage and were further studied under in-vitro conditions. These genotypes recorded relatively more larval mortality, prolonged larval and pupal duration with reduced adult emergence of T. absoluta. Among these six genotypes, S. pennellii (LA-1940) showed resistance both under choice and no choice bioassays with higher number of type IV trichomes, highest total flavonoids and phenols. In general, glandular trichomes (GTs) (type I, IV, VII) showed negative correlation in different genotypes of tomato with reference to larval number/plant, percent damage and adult activity, whereas type V (non-GTs) showed negative correlation with number of larvae/plant.

Efficacy of integrated pest management tools evaluated against Tuta absoluta (Meyrick) on tomato in India ABSTRACT: South American tomato moth, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is an invasive pest on tomato and other solanaceous crops. In general, 20 to 30 % yield loss is caused by this pest and sometimes it may result in 100% damage, if timely management interventions are not followed. Though the pest was reported in India during 2014, presently it has spread to several tomato growing states. In the present study various IPM tools have been evaluated against this pest. As a long-term strategy of resistance breeding, genotype screening was carried out for identification of resistance sources from wild and cultivated tomato genotypes showing resistance/tolerance against T. absoluta. Among the evaluated wild and cultivated tomato genotypes, Solanum pennellii (Accession, LA 1940) was identified as a resistant source against T. absoluta both under choice and no-choice bioassays and is being used for resistance breeding. Various entomopathogens (Bacillus thuringiensis, Metarhizium anisopliae, Beauveria bassiana and M. rileyi), egg parasitoids (Trichogramma chilonis, T. pretiosum and Trichogrammatoidea bactrae), light traps, pheromone traps, synthetic insecticides, botanical origin insecticides were also evaluated for their relative efficacy. Among the egg parasitoids T. pretiosum and among synthetic chemicals, spinetoram 12 SC@ 1.25ml/l were found very effective for the management of T. absoluta. Yellow light traps were found as an effective component for integrated management of T. absoluta. Azadirachtin 5% EC at the tested concentrations showed highest mean radial growth (24.67 mm) with relatively less inhibition (16.51%) of M. anisopliae indicating these combinations can be effectively utilised in the eco-friendly management of T. absoluta. We reported natural incidence of M. anisopliae on T. absoluta larvae, causing up to 35 per cent mortality during 2016-17.

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