Antennal transcriptome sequencing and identification of candidate chemoreceptor proteins from an invasive pest, the American palm weevil, Rhynchophorus palmarum

Abstract

For decades, the American palm weevil (APW), Rhynchophorus palmarum, has been a threat to coconut and oil palm production in the Americas. It has recently spread towards North America, endangering ornamental palms, and the expanding date palm production. Its behavior presents several parallelisms with a closely related species, R. ferrugineus, the red palm weevil (RPW), which is the biggest threat to palms in Asia and Europe. For both species, semiochemicals have been used for management. However, their control is far from complete. We generated an adult antennal transcriptome from APW and annotated chemosensory related gene families to obtain a better understanding of these species' olfaction mechanism. We identified unigenes encoding 37 odorant-binding proteins (OBPs), ten chemosensory proteins (CSPs), four sensory neuron membrane proteins (SNMPs), seven gustatory receptors (GRs), 63 odorant receptors (ORs), and 28 ionotropic receptors (IRs). Noticeably, we find out the R. ferrugineus pheromone-binding protein and pheromone receptor orthologs from R. palmarum. Candidate genes identified and annotated in this study allow us to compare these palm weevils' chemosensory gene sets. Most importantly, this study provides the foundation for functional studies that could materialize as novel pest management strategies.

Perspectives for Synergic Blends of Attractive Sources in South American Palm Weevil Mass Trapping: Waiting for the Red Palm Weevil Brazil Invasion

“…Given that Rhynchophorus has a palm borer lifestyle, the damage is based on larvae survivorship in the host palm trunk coupled with late damage and infestation diagnosis [ 17 ]. Thus, understanding the insect’s behavior is important for the implementation of new control strategies, especially those derived from research on telemetry [ 37 ], semiochemical interference [ 38 , 39 , 40 , 41 ], new secondary metabolites and formulations [ 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 ], early infestation detection [ 50 ], novel biopesticides [ 51 , 52 , 53 , 54 ], and natural enemies [ 55 , 56 ].…”

“…Molecular biology has provided some promises [ 39 ], eliciting interest in adopting biotechnological alternatives to pest control, mitigating the damage in different crop pests. The RNAi technique breaks the odor-binding protein, thus preventing the insects from tracking specific semiochemicals [ 38 ].…”

“…The RNAi technique breaks the odor-binding protein, thus preventing the insects from tracking specific semiochemicals [ 38 ]. The interruption of the olfactory ability leads to reduced pheromones detection and suggests a promising alternative for R. ferrugineus [ 39 , 106 , 109 ]. The RNAi silencing of R. ferrugineus RferOBP1768 appears in EAG tests with a reduction in the weevil responses to the aggregation pheromone.…”

Genome-Wide Identification of the Gustatory Receptor Gene Family of the Invasive Pest, Red Palm Weevil, Rhynchophorus ferrugineus (Olivier, 1790)

“…The number of gustatory receptor genes in R. ferrugineus reported in this study (50 genes encoding 65 functional receptors) is higher than in previous studies, which identified genes from the transcriptomes (9–15 genes) [ 58 , 60 ]. A recent antennal transcriptome study in the American palm weevil, Rhynchophorus palmarum , has identified only seven gustatory receptor genes [ 78 ]. We believe that the transcriptome technique has many limitations in identifying Gr genes.…”

Identification of Candidate Olfactory Genes in Scolytus schevyrewi Based on Transcriptomic Analysis

“…The genes reported in our study provide additional knowledge on the pool of identified olfactory genes in coleopterans. Compared with a large number of studies on Lepidopteran species, the current understanding of olfactory genes in Coleoptera is mainly sourced from a few reported studies on T. castaneum (Engsontia et al, 2008 ), Megacyllene caryae (Mitchell et al, 2012 ), I. typographus , and D. ponderosae (Andersson et al, 2013 ), Leptinotarsa decemlineata (Liu et al, 2015 ), H. parallela (Yi et al, 2018 ), Rhynchophorus ferrugineus (Antony et al, 2016 ; Gonzalez et al, 2021 ), etc. S. schevyrewi belongs to the genus of bark beetles and shares similar biology with the related species that are destructive forest pests, such as I. typographus and D. ponderosae .…”