The tomato leaf miner, Phthorimaea (Tuta) absoluta, Meyrick 1917 is recognized as a highly destructive pest, causing significant economic losses to crops in both greenhouse and open field environments across four continents: Asia, Africa, Europe, and South America. High genetic homogeneity among populations from various regions and countries indicates significant gene flow between P. absoluta populations, suggesting a lack of geographical barriers to dispersion. Furthermore, P. absoluta has developed resistance to insecticides due to target-site mutations or metabolic resistance, which enable the insect to withstand lethal doses of insecticides. To control this insect pest, the plant-mediated RNA interference (RNAi) is most promising host-induced gene silencing technique, utilized the plant’s machinery to express double-stranded (dsRNA), which triggers the RNAi pathway in P. absoluta. Due to thermal tolerance, the P. absoluta has increased its area of invasion by 600 km per year over 9 years. Female P. absoluta releases pheromones that are recognized by males with a sophisticated olfactory circuit on their antenna. Pheromone binding proteins (PBPs) play a crucial role in mate recognition and attraction, and their expression peaks during courtship, specifically around 6:00 a.m. Given its potential to significantly alter the insect genome, clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) offer a revolutionary strategy to control P. absoluta. Furthermore, this pest has developed remarkable adaptations to survive on unfavorable hosts by secreting specific proteins from its salivary glands that detoxify plant defenses. Insecticide resistance is likely the cause of field control failures of P. absoluta. Biological control, sex pheromone traps, and cultural control are the most promising approaches to address insecticide resistance resulting from these failures. Therefore, the implementation of integrated control programs and appropriate resistance management strategies is necessary to keep P. absoluta infestations under economic damage thresholds.
Zhang et al. (Tue,) studied this question.